Category: desert gardens

Best native shrubs for relentless desert heat

Here we are in September with weather that used to belong to July. With weather this hot it is too early to plant shrubs and trees in your garden. Wait until the daytime high air temperature is 90 degrees Fahrenheit or less. That 90F temperature is a useful indicator that the soil has cooled off enough. Hot soil can kill a newly installed plant within days.

Now, however, is not too early to plan adding tough native shrubs to help minimize the effects of the blistering heat next year.  (And it will be blistering hot next year. You can count on it, as the climate changes.)

While you may think “I need to plant big trees to cool my garden”, in fact, shrubs can definitely help by shading smaller areas and the lower sides of your home. Shrubs also keep the ground beneath them cooler and your overall garden at a lower temperature. The shade shrubs cast can create a haven for small wildlife like birds, lizards, bees and other insects.

So here are a few favorites, most are evergreen and all, but two, are native to the U.S. Southwest. (And those two are tough Aussies!)

1. Texas Ranger (Leucophyllum frutescens)

Also known Texas Sage, is a staple in desert landscaping due to its low water needs and striking silvery foliage. Imagine how glorious a hedge of these will look as this hardy shrub bursts into a display of purple blooms when the summer humidity gets high. It thrives in full sun and poor but well-drained soils, making it an ideal choice for low-maintenance gardens. Whatever you do, do not trim your Texas Ranger into a lollypop shape. It is naturally a loose, open, and graceful shrub that reaches up to 6 feet in height and will live for as long as 30 years. ProTip: trying to bring on blooms by watering the plant, won’t work.  It takes the increased humidity of the monsoon for the Texas Ranger to flower.

Desert Willow Chilopsis linearis

2. Desert Willow (Chilopsis linearis)

Desert Willow (Chilopsis linearis) can be grown as a small, messy tree or multi-trunk shrub. But messy as it is, the Desert Willow is popular because it will survive on its own with no extra water or fertilizer required.  Grows two to three feet a year and reaches a height of 15 to 20 feet and will live for over 40 years, if planted no higher than an elevation of 5,000 feet. It can be found in the wild in all the major Southwestern deserts from Chihuahuan to the Mojave to the Sonoran and the Colorado desert. As a desert native it needs little care and will produce red, pink, white, and purple flowers for months on end, but, I repeat, it is a messy tree dropping those long, brown seed pods for you to clean up. Now read about the next tree, a tidier hybrid of the Desert Willow.

3. Chitalpa trees (Chitalpa tashkentensis)

Chitalpa trees can grow as large, multi-stemmed shrub or a single-trunk tree. Unlike its cousin the Desert Willow, Chitalpa trees were created by scientists to be sterile and do not have those long, pointy seed pods. Their leaves are wider and create more shade. For that reason, the Chitalpa, like its cousin, is often planted as a street tree that blooms for months on end without supplemental watering. This hybrid thrives in endless sunshine and grows very fast to 30 feet tall. It’s said to live up to 150 years which seems a bit unlikely to me, but it you can be sure it will be growing where you plant it even after you are no longer gardening. Hummingbirds and bees love its pink or white orchid shaped flowers.

4. Jojoba (Simmondsia chinensis)

Jojoba (Simmondsia chinensis) has been an ignored shrub of the Sonoran Desert and Baja. The oil from the seeds was used for centuries by native Americans to treat skin conditions such as psoriasis and eczema.  A few decades ago, young women who were advocates of natural skin care “discovered” it and the oil was added to many skin and hair care products as a hydrating agent as well as having skin health benefits. But, skin care aside, it is simply a nicely shaped, round shrub that grows to a height of three to six feet with gray-green leaves year ‘round with seeds that go from green to dark brown. Oil is relatively easy to express from the seeds. It is highly drought-tolerant and reputed to live for decades.

5. Littleleaf Cordia (Cordia parvifolia)

Cordia parvifolia is a low maintenance plant which is not common in hot, dry gardens – but it should be. It is very drought tolerant once established. Ideally, it should be planted in locations with full sun and will produce large white flowers for months on end from early spring to fall with supplemental irrigation. This native of the Sonoran and Chihuahuan deserts is a dense shrub with arching branches that grow up to 6 feet tall and wide, making it suitable for hedges or as a standalone plant. You may have to call around to garden shops or plant nurseries to find it and you may end up finding it at a native plant nursery. In a pot it is disappointing, but plant it in the ground and this shrub with its white flowers becomes a beauty.

6. Feathery Cassia (Senna artemisioides)

Feathery Cassia, a native of Australia, is smaller shrub with feathery leaves that can tolerate very high temperatures. Known for its wispy, gray-green foliage and bright yellow flowers, which bloom in late winter and early spring, this plant provides seasonal color while maintaining year-round interest. Its flowers are also very fragrant attracting bees and other insects. Feathery Cassia grows up to three to four feet tall and wide, making it suitable for smaller spaces or as a border plant. It thrives in full sun and well-drained soils, needing little water beyond what falls from the sky once it is established.

7. Lantana (Lantana camara)

This native of the African tropics and popular in Australia, has spread around the world because it thrives in hot climates and blooms with colorful flowers for months on end. In the U.S. Southwest the Lantana camara, the upright version of this shrub, can become an attractive hedge. (In places like the damp U.S. SouthEAST it has become an invasive plant to be eradicated if possible.) Please note that for a hedge or a taller shrub you want to get the Lantana camara, not the low-growing, mounding Lantana montevidensis, also called trailing Lantana. Planted densely, as shown in the photo, the upright version will grow to 6 feet tall and as wide as 5 feet and can be trimmed into a tidy hedge. And as for flower colors — they seem to be endless! Mix them up.

8. Creosote (Larrea tridentata)

Why no photo for creosote? When doing research for this post, I asked the artificial intelligence ChatGPT for a list of native desert shrubs suitable for residential gardens to see how its list compared to mine. The first on its list was creosote. What?? Creosote is basically a weed in most Southwestern deserts. In Tucson there are actually neighborhoods with acres and acres of creosote “forests” dense with volunteer plants that are about 5 feet tall. They provide privacy to homes built in the back of the property decades ago, but no one planted the creosote bushes; they just grew. Creosote’s one claim to fame is that it/they can live for centuries. It’s true. New plants spring up from the roots of the older ones forming an ever-widening circle of creosote. One creosote circle in the Mojave was dated to 10,000 years old! Maybe one day ChatGPT will “read” this and realize that it gave bad advice. Don’t plant creosote.

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Growing a backyard orchard

Imagine stepping into your backyard and being greeted by the sight of thriving fruit trees ladened with succulent, sun-kissed fruits. A dream? Not at all. It takes a little planning and some digging but you can easily start a backyard orchard this weekend in your desert garden.

On left, green figs and on right, ripe peaches. Both would be delicious fresh from the tree in your garden and on your table. (Photo of peaches on tree by Czapp Botond on Unsplash.)

Not all fruit trees are created equal

First you need to select the right varieties suited to arid conditions in order to create a successful backyard orchard. Opt for drought-resistant and heat-tolerant species such as pomegranates, figs, quinces, citrus trees (like oranges and lemons), and stone fruits like nectarines, apricots, plums, and peaches. These varieties have adapted to thrive in the challenging conditions of a desert environment.

(Note that citrus trees do not do well in low desert locations like Phoenix. And fruiting olive trees and mulberries are banned in Las Vegas, NV and Pima County, AZ.)

If you want to branch out, consider adding nut trees like pecans to your orchard. Keep in mind, however, that pecan and other nut trees (and fig trees) grow very tall and may put the rest of your garden in the shade–literally–blocking out almost all sunlight.

Soil Preparation and Watering

Desert soil always poses challenges, so you need to start your mini-orchard by improving the soil structure with organic matter, such as compost. This should enhance water retention and nutrient levels. Adequate drainage is also crucial to prevent waterlogging, especially in desert climates where heavy rains can be sporadic but intense.

To install your fruit trees dig a hole that is only as deep as the root ball, and be sure that it is three times as wide. This will allow roots to spread out, grow faster, and anchor the tree better.

After the young fruit trees are installed it is important to set up a drip irrigation system to ensure a slow, steady release of water directly to the root zones, minimizing evaporation and wastage. Use mulch around the base of your fruit trees to further retain moisture and regulate soil temperature.

Protecting Against Extreme Temperatures

Desert climates are notorious for their extreme temperature fluctuations. To protect your new fruit trees consider installing shade cloth during the hottest parts of the day. It can be just something as simple as an old sheet or length of burlap draped over the top of the tree. As you can see in this photo from the Tucson Mission Garden, this cloth cover will shield the trees from the intense sun and reduce stress on them. Additionally, planting trees in locations that receive some natural shade during the day can provide relief from the harsh afternoon sun.

Pruning and Maintenance

Regular pruning is essential for shaping your backyard orchard and promoting healthy fruit production. Pruning regularly and tightly also lets you plant trees much closer together so you can grow more fruit. For example, nectarines only produce fruit on new growth so they should be pruned annually. On the other hand, pomegranates need almost zero attention. And fig trees, if left unpruned, will grow to 20 to 30 feet tall and cast deep shade.

Prune during the dormant season, typically in late winter, to remove dead or diseased branches and encourage new growth. Avoid over-pruning, as some fruit trees in desert climates may benefit from a bit more foliage for sun protection.

Timing Matters and Size Doesn’t

Fall or early Spring are the best times to plant trees — or almost any long-lived tree or shrub–in a desert garden. By planting now you will allow the new trees to acclimate and establish strong root systems before the scorching heat of summer arrives.

If you have any doubts about planting a backyard orchard because you think the space is too small, I hope you can visit the Tucson Mission Garden. You will see fruit trees planted densely and producing fruit, especially figs, abundantly. And then think of how good your own home-grown fruit will taste in a summertime fruit salad.

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Fixing that neglected side yard

It’s long. It’s narrow. And a home’s side yard is usually given little attention. Perhaps the original builder or an earlier owner spread a layer of rocky mulch on the soil and added a few stepping stones along the unused passageway from the front to the back of your home. But often it is not even considered part of the garden.

I have to confess that I ignored my current home’s side yard. A previous resident had, in fact, covered the 10 foot wide strip with reddish brown rock mulch. No stepping stones, however. There are pockets of grass where baby Mourning Doves huddle together and, in another corner, one rugged, volunteer Lantana plant survives. On one side of this passageway is a 6 ft. tall wood fence and on the other, the pale, sand-colored stucco wall for my living room. No windows — thank goodness.

Then, one day this last summer when it was once again 110 degrees fahrenheit outside here in Arizona I realized how much cooler that side of my home–the south side–would be if I planted something tall and shady there–a tree that was very drought resistant and wouldn’t die in relentless 100F+ heat.

Two drought tolerant trees for shade

My first thought was to install a Palo Verde tree in late October or November, when Fall planting season starts. I love this Arizona native’s brilliant yellow blossoms in April but once the flowers are gone, it would only provide a light screen effect with its leafless branches. Not much help countering the blasting sunlight in summer.

Then, I thought, what about another favorite of mine, the long-blooming Chitalpa (Chitalpa x tashkentsis)? Its branches would be ladened with pink flowers for months on end. And Chitalpa trees have leaves to cast more shade than the Palo Verde. Better yet, they grow fast and are so tough that in Las Vegas and Tucson they’re planted as street trees.

But I had to face reality: the passageway is only 10 feet wide and both the Palo Verde and the Chitalpa should be planted a minimum of 15 feet away from the side of a house.

So, a tall, skinny tree was called for–like an Italian Cypress (Cupressus sempervirens) which I know grows in Los Angeles and the Mojave desert. I haven’t seen many of them here in Sonoran desert gardens. A friend in Vegas planted a wall of them but looking at her garden now, maybe that is not the solution–especially when I check the price for 5 or 6 trees. I’ve been told that they suffer from red mites and if not watered deeply they will die.

Thanksgiving and cooler weather arrived and I stopped thinking about shady trees for my side yard. But in that doldrum week between Christmas and New Year, I began to consider it again.

Tough shrubs are a shady solution

Shrubs, I decided. Big, leafy, drought tolerant shrubs–maybe 5,6 or 7 feet tall–planted like a wall of shade next to the house. They will never grow tall enough to shade and cool the roof, but drought tolerant shrubs could block some of the blasting sunlight heating up the stucco. (Yes, Yes, I know I wrote about shrubs to cool concrete block walls last January. I’m now following my own advice.)

lantana hedge in Pasadena

Texas rangers (Leucophyllum frutescens) and upright Lantanas (Lantana camara) immediately came to mind. Both bloom often throughout the year, usually after some rain falls.

With some strategic trimming colorful Lantanas, like the ones in a hedge in Pasadena, can be encouraged to grow to 5 feet high. The Texas Rangers, however, I plan to leave untrimmed. I hate what commercial “gardeners” do to these beautiful, loose shrubs: whacking them into a lollipop shape with most of the lovely purple flowers cut off.

I’ll plant in February when we have had more rain and the soil is beginning to warm up. Now to figure out what to do to my back yard where a neighbor’s small tree died last year. It shaded both our yards and cut off the view from two homes behind us. Maybe that’s the right place for a Palo Verde or Chitalpa. I’ll let you know.

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Visit my author’s site to see the books I’ve published.

Harvesting monsoon rain saves gardens

Climate change clearly has arrived in the American Southwest with scorching heat daily. And sadly, no monsoon rains yet, even though monsoon season officially started on June 15th. 

We all hope that storms will be sweeping in from the Gulf of Mexico and Sea of Cortes soon. That’s what the TV weather forecasters keep telling us nightly. So now is the time to prepare to capture that rain water. And by doing it now you will already be prepared to harvest rainfall again when winter storms arrive. (6 hours after I posted this a fierce monsoon storm struck Tucson. Maybe I should have posted it earlier.)

There are basically two methods to keep water in your garden for future use. One is to save it in above-ground or below-ground containers and the other is to help the rainfall percolate into the soil instead of running off your property and away from your plants.

Start with your flower beds

While most flower beds are mounded — hopefully because you add a thick layer of organic mulch twice a year — you may want to consider digging little basins in the center of the beds to capture as much rain as possible. Be careful not to damage the roots of your plants. The water will then seep into the earth for future use by the plants.

If you plant in raised boxes, be sure to have good drainage on the bottom or during a heavy downpour your planter may flood and drown the plants.

High priced infiltration or on the cheap

Infiltration, in its costly form, involves digging a large pit in your yard to hold rain runoff from your roof. This means rain gutters and downspouts must be installed. The pit must be lined with a strong, permeable material and must have an overflow to channel excess water away from your home. Water will seep from the pit into the surrounding soil, thus “irrigating from underground.” Consult a landscape architect or soils engineer if you plan to do this.

In the less expensive version of infiltration, dig or drill narrow, deep holes spaced apart in a circle around trees and shrubs. These holes will fill with rain which will then seep into the soil. To do this effectively, you may have to line the holes with strong, permeable material to prevent the sides from collapsing into the holes while allowing water to escape into the root zone. Some people recommend using French drains, those metal drain pipes with holes, installed vertically like mini-wells.

In the super-cheap version, very coarse gravel or small rocks may also keep the holes from collapsing. Deep watering like this will encourage trees and shrubs to grow deeper, stronger roots. And deeper roots mean more stability when the seasonal winds howl across the landscape in Spring and Fall.

Install cisterns or rain barrels

Our last suggestion is to add a cistern or rain barrel to capture rainfall which you can use later by pumping the water out for irrigation. Unlike infiltration which is designed to allow water to spread out underground during and after a storm, a cistern is supposed to hold water in the container, not diffuse it.

If you want to add an underground cistern–which is essentially a well filled with rainwater–you should consult with a landscape architect or soils engineer because there are engineering and permit issues involved. The sides and bottom must be sealed to prevent water from escaping and the system must have an overflow drain. If water overflows in the wrong direction you may have serious and potentially expensive erosion problems from damage to your home or your neighbor’s house!

On the other hand there is a simple way to capture rain: buy a big plastic barrel or one of the large above ground cisterns–prices start at about $70 and go up into the thousands depending upon the size. It can be a quick and easy method to store the rainfall from the downspouts on your roof to use later. The big risk here is that the rain falls so intensely that the barrel overflows and starts flooding the area before you notice it.

Are cisterns still illegal?

Happily and wisely, the laws in Colorado and Utah banning water harvesting have changed. Now Coloradans can have 2 rain barrels with a total capacity of 110 gallons of water for use on their own property. In Utah homeowners can save up to 2500 gallons of rainfall in above or below ground cisterns for use on the same property. In both these states, please check for specific regulations.

Many other states, including Texas, Nevada and California, now have laws supporting rainfall harvesting and rules regarding usage. These states now allow saving rainwater that falls on your roof and using it in your garden. Using the water for drinking water is banned in some states, discouraged in others. My advice: do not drink it. Give it to your garden.

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Visit my author’s site to see the books I’ve published

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How to make wildlife happy in your garden

You’re probably happy with your gardening efforts — with good reason. After all, you…
– planted a tree on the south or west side of your home to cool it
– removed your front lawn…and perhaps kept some grass in the backyard for a children’s play area
– even added one (or more) shrubs along that concrete block wall to minimize the heat.

So congratulations!

But this post is about why you should take a second look and see your garden through the eyes of a hummingbird, lizard, butterfly, quail, ground squirrel, or other wild creature that may live in your area. (But not javelinas or bears. They are clearly not animals you want to encourage.)

You may even want to re-think your garden as a haven–a kind of “happy place”–for wild creatures in your neighborhood and, thus, deserving of being a Certified Wildlife Habitat. Complete with an official metal plaque you can order and post in your front yard.

The National Wildlife Federation (NWF) and the Arizona Wildlife Federation set standards for having a Certified Wildlife Habitat and the official plaques come from them. They state that in order to be Certified a garden should provide wildlife with food, water, cover from predators, shelter for raising the young, PLUS do all this sustainably.

Start with food for wild creatures

For wildlife food the NWF suggests that you plant natives with colorful flowers and lots of seeds. It’s not necessary, however, to install only native plants because natives often bloom all at once. Other drought-tolerant plants that bloom and produce nectar or seeds at different months during the year can be suitable additions to your wildlife-friendly habitat. For example, you could plant South African natives Pink Trumpet Vine (Podranea ricasoliana) or Cape Honeysuckle (Tecoma capensis) for summer nectar for bees and birds. Humingbird and birdseed feeders can also be good additions to your backyard.

Then next to those vines, for example, plant a desert native Brittlebush (Encelia farinosa) and Mexican Gold Poppies (Escholtzia mexicana) to produce seeds. (Click below to see images of each.)

  • Pink Trumpet Vine Podranea ricasoliana
  • Capoe Honeysuckele
  • Mexican poppies in Tucson

Daily water is a must-have

To provide water, small shallow plant saucers or bowls are your best bet. Backyard fountains look glorious, but given the water problems–and potential water rationing–in the American Southwest, fountains should be disconnected and turned into planters.

Add a few small stones to the plant saucer to help smaller creatures, such as little lizards or little birds, drink comfortably from this water source.

Hidden from danger

Like humans, wildlife wants shelter from predators and shelter to raise young. These can be identical. Trees and shrubs–from short to tall–are excellent hiding places and nesting sites for birds, as well as havens for insects and lizards. These two photos, taken at the Tucson Botanical Garden, demonstrate wildlife-friendly gardening with shrubs at various heights combined with tall trees. There are also hiding places between the pots shown in the second photo.

What you don’t see in these photos are wide stretches of rock mulch with one or two plants. In a good wildlife garden at ground level, attractive ground covers, like cacti and succulents as well as Lantana montvidensis, hide small creatures from predators. Lantana is also a good food source for bees. (In the first photo a fountain appears in the back right side, but we do not recommend adding fountains these days!)

  • lantana montevidensis yellow blooms

Now, the last requirement for Certification as a Wildlife Habitat is that the garden is sustainable. You probably already do much of this: minimize or eliminate lawns, harvest water, avoid pesticides, use natural mulch, and use only drip irrigation.

Do all this and you, too, can have a Certified Wildlife Habitat. You can take the first step here.

While this post is primarily written for gardeners in the arid U.S. Southwest, these standards for a wildlife-friendly garden apply worldwide including Australia, the U.K., Cyprus, and Middle East where many Hot Gardens subscribers live. And where many native creatures are now struggling to survive due to climate change.

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Turn a love of gardening into extra cash

Mother Nature can be your BFF if you want to turn your love of gardening into a source of extra spending money. And it is so simple. All you need are inexpensive pots you can buy on Amazon or your local garden center, some potting soil and patience. Then, on a sunny Saturday, hold your “garden sale” on your driveway.

Here is how to start creating cash from plants

varigated pelagornium geranium

Take cuttings from special plants in your garden and plant them in small plastic pots–like the ones you see in the local garden center. Actually, the plants don’t have to be rarities, but they do have to be healthy. For example, if you have a sturdy geranium (Pelargonium) with pretty blooms or varigated or scented leaves, take a few 4″ to 6″ long cuttings for starters. Then stick the cuttings in a inexpensive plastic pot filled with good potting soil. And water frequently. If you think that your geranium seems too ordinary, keep in mind that you liked it enough to buy it, so, no doubt, other people will like it too. You could even have an example in bloom nearby during your garden sale so people can see how attractive it is. It may take six weeks for the geranium cutting to take root.

Divide to multiply

Another example of a plant to sell would be iris, which grow well in hot dry climates as well as looking beautiful. You should divide iris rhizomes every 2 to 5 years anyway, so why not keep some and offer others for sale? Be sure to cut the leaves back to 5 to 6 inches and clearly label the color and if the iris is a rebloomer.

Depending upon where you live, you may also have agapanthus in your garden and they are good candidates for dividing. Simply dig up the root ball, cut it into 2 or 3 large size pieces, replant one section in your garden and sell the others. You should probably divide the iris and the agapanthus just before your driveway garden sale. They should not dry out before replanting. It might also be helpful to your customers to have a little note to give them about planting iris and agapanthus. Each has different requirements.

Then there are seedlings–pick your favorite annual flowers and herbs–which should be started in very small pots again like at the garden center. Then water and wait.

Mother Nature should do her work within a few weeks. The cuttings will have taken root and the seeds should have sprouted to produce seedlings.

Advertise your private garden sale

Then hold a “garden sale” on your driveway on a Saturday morning. Post signs around your neighborhood. List your garden sale online on Craigs List or Next Door. Post notices about it on community bulletin boards. 

Before the sale begins do some research about pricing. As you probably know, iris rhizomes are expensive and agapanthus, too, so price yours accordingly. But geraniums are priced lower and herb seedlings even lower at garden centers and yours should be, too. And at the end of the garden sale day, you pocket the money you made and move any unsold pots into your back yard to continue growing until you hold your next garden sale.

Selling unusual plants for microclimates

Hot gardens plumeria blossoms
Plumeria blossoms are exceptionally fragrant and the plant–a small tree–can grow indoors.

Not long ago we spoke with a man at a California farmer’s market who had trimmed an old tropical Plumeria tree in his back garden and put the 2 foot long ends of the trimmed branches into big plastic pots filled with rich potting soil.  Several months later, when he was confident the cuttings had taken root, he held a garden sale on his driveway based on one ad on Craigs List. And he earned over two thousand dollars over two weekends.

A few weeks later he showed up at a farmers’ market with the few remaining potted Plumeria and proceeded to sell them in another couple of weekends. His goal for his garden sale was to raise money for his daughter’s college education.

One of the reasons he was so successful was that Plumeria trees had just begun making a comeback in popularity after 50 years of being pretty much ignored.  His Plumeria was also of a rare color, which made it all the more desirable and allowed him to charge higher prices.

It’s important to note that Plumerias need a sheltered microclimate in a Southwest desert garden; their leaves will burn when subject to intense, all day sunlight. (Sorry, Phoenix, no plumeria trees for you.) On the other hand, they do well in Mediterranean climates where the temperature doesn’t rise over 90-95F very often.

Cacti and condos – meant for each other

A retired couple we know sell succulents and cacti in small, colorful pots at a local open air market for extra retiree income. Cacti and succulents are often the plants of choice with apartment and condo owners because they grow very slowly and can be ignored for weeks without whithering and dying. Of course, cacti and succulents are the mainstay of many desert gardens so homeowners are also potential buyers.

And as with the other garden sale ideas in this post, Mother Nature does most of the work in producing the products you sell. And you harvest the profits.

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Visit my author’s site to see the books I’ve published.

Should you get gardening advice from an A.I.?

You’ve probably already heard about ChatGPT, the new artificial intelligence program by OpenAI that is being called “scarily good.” Well, okay, I thought, maybe it is scarily good about techy stuff but how good is it with gardening advice? So I asked it this fairly basic question.

chlorosis shrub leaves

What causes plant leaves to turn yellow with green veins?

Here is what ChatGPT answered:

“Leaves on plants that turn yellow with green veins is a condition known as chlorosis. Chlorosis is caused by a lack of chlorophyll, which is the pigment that gives leaves their green color. The green veins on the leaves indicate that the plant is still producing some chlorophyll, but not enough to fully color the leaves.”

Okay — so far so good, I thought. And it continued…

“There are several causes of chlorosis, including:

  1. Nutrient deficiencies: A lack of iron, manganese, zinc, or other essential nutrients can cause chlorosis. This is often due to a lack of these nutrients in the soil, or a pH imbalance that makes it difficult for the plant to absorb them.
  2. Disease: Some plant diseases can cause chlorosis, such as leaf spot or rust.
  3. Pest infestations: Pests such as spider mites or aphids can suck the sap from the leaves, causing them to turn yellow.
  4. Environmental factors: Extreme heat, cold, or drought can stress plants and cause chlorosis.”

Item 2 is where ChatGPT begins to slip off the track. Leaf spot or rust do not look remotely like chlorosis; they are orangy yellow round spots on leaves not yellow leaves with green veins. Spider mites and aphids can damage plants but the effect is also spotty leaves–smaller spots–not leaves yellowing.

Then Chat GPT goes for the solution:

“To fix this issue, you need to find the root cause of the problem and take appropriate action. A soil test can help you determine the pH and nutrient levels in your soil and make recommendations for correcting any imbalances. You can also consult with a local nursery or botanical garden for help identifying and treating any diseases or pests that may be affecting your plants.”

That’s where ChatGPT ends.

My conclusion is that it offers basically good advice–as I did in an earlier post about yellowing leaves. But it falls short of the detailed information I wrote about, including short term, fast fixes to out-of-season yellowing leaves. ChatGPT clearly hedges its bet by suggesting that one should consult with a real local human being. (Or maybe a Master Gardener!)

Is ChatGPT trustworthy?

OpenAI, the company that developed this A.I. warns not to trust what ChatGPT says completely — that it sometimes just makes things up. This is a failing of other artificial intelligence programs, too. My guess is that it doesn’t want to appear ignorant — which, of course, opens the question about whether an artificial intelligence computer program can behave as if it is embarrassed by a lack of knowledge — but that is for another blog. Not this one.

I have another gardening question for ChatGPT — one that should be more challenging, but, unfortunately, the Open AI website is so busy that I haven’t been able to get on it again. I’ll report about it, if I can talk with it again.

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Where to get free or cheap trees in L.A., Phoenix, San Diego and…

The push for increased tree planting in cities around the world swells with each disruptive weather event. Whether it is reflected in nation-drowning floods in Pakistan or wildfires sweeping mountainsides bare in California, climate change has arrived. And ordinary people are saying: “We gotta do something.”

In response to clamor from citizens to “do something”, several U.S. Southwest city mayors have begun to set goals for the number of trees that should be planted in their communities. And they have enlisted the aid of organizations–usually utility companies–to help them by offering free or discounted small trees.

Before I go into how to get free trees locally, however, I want to answer a basic question.

Why plant trees?

Tree planting in cities has gone on for decades, mostly for aesthetic reasons. People like living and walking along tree-lined streets. There are now two other reasons to plant a tree at your home.

A street lined with Palo Verde trees that bloom brilliant yellow in April.
  1. As I wrote in the previous post, trees can become green canopies, natural umbrellas to cool hot city streets, sidewalks and other hardscape. It is a simple mechanical process: tree leaves blocking, reflecting or minimizing sunlight means cooler air and a cooler landscape underneath.
  2. There is also a chemical process that occurs when a new tree is planted. As they grow, trees absorb carbon dioxide, a gas that is a major contributor to climate change. Trees are carbon capturing plants that remove CO2 from the air and keep it stored in their leaves, trunk and branches. Less CO2 slows climate change. And the oxygen plants emit is the breath of life for people like you and me.

Trees planted for both these reasons make the world a pleasanter place for humans.

Ok. Now for those free trees

In Los Angeles, the Green New Deal identifies a goal of planting 90,000 trees. To reach that goal an organization called City Plants will deliver up to 7 free trees to your door. You have to plant them yourself but they provide instructions.

Crape myrtle

Don’t have space for another tree? They will also plant a street tree in front of your home or business, including obtaining the proper city permits.

City Plants also offers many “Adopt a tree” events for same day pick up of one fruit or shade tree. Check their website for details.

So who is picking up the tab for all this? The LA Dept. of Water and Power.

In Phoenix the goal is to plant 5,000 trees every year to increase the citywide tree canopy to 25%. It’s currently around 10%. Working in conjunction with Salt River Power and Trees Matter, Phoenix residents can take home 2 free desert native trees — mesquites, palos verdes, desert willows–after attending a Zoom meeting about planting and caring for trees. This program is underway for 2023.

San Diego is going in a different direction: homeowners receive a $35 rebate from San Diego Gas and Electric for each tree purchased up to a total of 5 annually. And–happy news for renters and condo owners–you don’t have to plant the tree in the ground. Put your 1 or 5 gallon starter tree in a big pot on your balcony or patio and you qualify for the rebate.

Chines pistache tree hot gardens

In Tucson, the goal is an ambitious Million Trees planted by 2030. Trees for Tucson, a part of the environmental organization, Tucson Clean and Beautiful, is selling locally grown trees for $30 each. You will have to plant the tree yourself.

A better tree deal comes from Tucson Electic Power. You can order up to 3 starter trees through their website for $5 each. They will send you an email about where and when to pick up your tree to take home and plant.

Like San Diego, Albuquerque uses a rebate program to help homeowners plant new trees. The ABQ Tree-Bate plan will pay a homeowner 25% of tree planting costs up to $100 as a rebate on the water bill. Better yet, the rebate can cover tree maintenance expenses and irrigation installation as well as the tree you plant from the city’s authorized list. Be sure to check the website before you rush out to buy a new tree.

And San Antonio, which really isn’t in a desert but I’m including it anyway, gives away free fruit trees at various special events around the city. (If you want more info about growing fruit trees in the desert go here.)

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Big goals but not involving homeowners

El Paso also has a goal of a Million Trees planted, but is working through a non-profit organization which solicits cash donations and does the planting itself. I couldn’t find anything about free or almost free trees for homeowners.

Another example of a non-profit soliticiting donations and doing the planting is Las Vegas where the mayor wants the city to plant more than 60,000 street trees by 2050 to provide shade and bring temperatures down in areas most impacted by the urban heat island effect. Nothing on the website about tree planting assistance for homeowners.

Now about those huge national and international tree planting organisations

I am suspicious of some of the organizations who will for a dollar or two or more promise to plant a tree on your behalf somewhere around the country or around the world. You may not be helping who you think you are. Some are commercial tree growers who plan to harvest the “tree you paid to have planted” in 15 to 30 years. “Your tree” may well become a roll of bathroom tissue! These people are not restoring permanent forests!

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Visit my author’s site to see the books I’ve published.

Best 9 trees to combat climate change in the Southwest

Here in the hot, dry region of the U.S. Southwest tree planting has become more urgent as year after year the days get hotter and drier. The driving idea behind the tree planting efforts is to create a green canopy, a natural, cooling umbrella over cities.

In Las Vegas, the Mayor’s goal is to have 60,000 new trees planted by 2050.

In Tucson, the mayor is more ambitous: she wants to see a million new trees planted by 2030. El Paso, too, has set a million tree goal.

And In Los Angeles, one volunteer group, City Plants, installs 20,000 trees for free along the city streets every year. (More about free or almost-free trees in Western cities in my next post.)

If you want to do your part, but on a personal, residential scale, consider planting one or more of these trees–plus one shrub, the Chaste tree. Many are as wide as they are tall. They are all drought-tolerant and cast shade to cool your home and garden. I’ve added information about how tall the tree should grow, how fast it will grow and how long the tree should live. (Hint: All but one should outlive you!)

Trees that bloom in the Spring and Summer

Sweet Acacia (Vachellia farnesiana) is a species of thorny shrub or small tree. Brilliant yellow ball-like flowers, which are used in perfume industry. Will grow to 20 feet tall x 20 wide, moderate to fast grower. Lives 20 to 30 years.

Palo Verde (Parkinsonia florida) is a native to the Sonoran desert and is recognizable by the green color of its trunk and branches. Almost leafless most of the year, so it casts only a light shade. It bursts into brilliant yellow bloom in April. Grows 2 or 3 feet a year to 15 to 30 feet tall with an umbrella-like canopy. Lives 100+ years.

Desert Willow (Chilopsis linearis) can be grown as a small, messy tree or multi-trunk shrub 30 feet tall. Grows 2 to 3 feet a year. Lives from 40 to over 100 years, if planted no higher than an elevation of 5,000 feet. As a desert native it needs little care but, I repeat, it is a messy tree dropping those long, brown seed pods for you to clean up.

But read about the next tree, a tidier hybrid of the Desert Willow…

Chitalpa trees (Chitalpa tashkentensis) can grow as large, multi-stemmed shrub or a single-trunk tree. Unlike its cousin the Desert Willow, Chitalpa trees were created to be sterile and do not drop those long, pointy seed pods. For that reason the chitalpa is often planted as a street tree that blooms for months on end. Loves the endless sun shine and grows very fast to 30 feet tall. And is said to live up to 150 years.

Trees that turn color in Fall

Fan Tex Rio Grande ash has leaves that turn to a brilliant gold in fall, unlike it’s cousin, the ordinary Arizona Ash (Fraxinus velutina) that lacks the golden yellow fall color. Both ash varieties are adapted for a desert climate with low water usage. It is moderately fast-growing tree that will grow to a height of 30 to 50 ft and may survive 50 years with proper care.

memoir writing guide ebook paperback

Chinese Pistache (Pistacia chinensis) is a pistachio hybrid that produces no nuts. In Fall the leaves on the male tree turn from green to gold to brilliant red then loses those leaves in winter. The female tree simply turns golden — not vibrant red. Grows 12 to 15 inches per year to a mature height of 25 to 40 feet tall and as wide. Should be planted in full sun; if planted in partial shade the result will be a lopsided tree.

Trees that need little maintenance

Mesquite (Prosopis velutina) commonly known as velvet mesquite, grows 12 to 24 inches per year to a mature height of 40 feet tall. Needs almost no care. It’s advisable not to plant it in a lawn that is regularly watered. Too much water or fertilizer weakens the roots of the mesquite which may then tip over during high winds. It will live for as long as 200 years. Equally durable in a desert garden are the Honey mesquite, the messy Screwbean mesquite and Chilean mesquite which has fewer thorns.

Chinese elm (Ulmus parvifolia). Capable of adding 12 to 36 inches of height per season, the drought-tolerant Chinese elm is a very rapidly growing tree with a weeping shape and deep shade underneath. Some lose their leaves in winter and others do not and it is not clear why this happens. This tree can grow to a height of 40 to 50 feet within 15 years. Lives 50 to 100 years.

A tree that produces fruit

Fig tree (Ficus carica) The common fig tree is a deciduous tree that can also be grown as a shrub or espaliered on a trellis. Produces fruit in 3 to 5 years. Grows 12 inches a year up to 30 feet tall and in its tree form ends up much wider than taller. Its large leaves cast very dark, cooling shade and a fig tree lives 50 to 200 years. For other fruit trees for the desert go here.

And my favorite shrub, the fragrant Chaste tree

Chaste (Vitex agnus-castus) is a hardy, fast-growing flowering shrub that produces bloom spikes of light purple, white, or blue flowers in mid-summer. If seeds and faded blooms are removed it will continue to flower. It has very fragrant leaves. Grows rapidly to a height of 20 feet — the size of a small tree–and lives for 15 to 20 years.

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Follow the 90 degree rule for planting

Fall is definitely the best time to plant in hot, dry Western gardens. It’s actually a good time to plant in much of the world, because, after all, Fall is when Mother Nature sows seeds.

But not just any Fall day will do. In the desert southwest, including parts of Texas and California, you should wait until the average daytime temperature drops under 90F before you plant.

The issue isn’t only the air temperature, but the temperature of the ground. The soil, especially native soil, is far too warm now for the roots of transplants to grow. Between the dehydrating effect of the air temperature on new leaves and the “cooking” effect of the hot earth on the roots, new transplants may not survive very long even if you water them frequently.

How to protect your transplants

Clematis in bloom
The Clematis jackmanii in my backyard.

However, if you just can’t wait to start gardening again after a summer hiatus, you may be able to protect your transplants by placing a piece of tile or broken terra cotta pot over the root zone, thus keeping it cool.

I did this with a Clematis Jackmanii, a plant not commonly found in a hot, dry garden. I planted it by a trellis in a very sheltered corner with a broken piece of pot over the root zone. It grew and bloomed then over winter it died back. The following spring it rose from the seemingly dead to climb the trellis and bloom again. To see other climbing plants for hot dry gardens, to here.


You could also add shade cloth to help reduce the temperature.

Should you avoid planting in native soil?

I have to admit that the Clematis was not planted in purely native soil. In most of the Southwest the soil is alkaline and lacking many of those tasty chemicals that hungry plants need. Realizing this, I made sure the Clematis was installed in a flower bed with super-enriched soil made mostly of organic mulch. And remulching twice a year is a must with our poor quality dirt which leeches all the good chemicals out of the mulch into the dirt within months. “Poor dirt” returns to being “poor dirt” rather quickly.

Another approach is to plant in raised beds, but those large wooden or metal boxes can become rather expensive. So, consider going to Amazon to find grow bags for a more affordable solution.

They come in small, medium and large and are good for growing almost every type of vegetable or herb. You can fill these bags with soil you buy at the garden center or mix native soil into the bag with commercial potting or top soil. And all the good, nutritious chemicals in the growing mixture end up feeding your plants — not dissolving into the surrounding soil.

Playing for Julia ebook

Prickly Pears may save us all

Well, I’m late with this, but according to a five-year study at the University of Nevada Reno, those ubiquitous prickly pear cacti (Opuntia) can become a new source of bioenergy feedstock to replace fossil fuel. This cactus also does double-duty as a land-based carbon sink removing carbon dioxide from the atmosphere and storing it in a sustainable manner. Just like trees do.

This is especially important because, according to a biologist at Saguaro National park as the climate in Arizona and around the world is changing prickly pear cacti are becoming more common. They really like the new weather conditions and poor quality soil is no problem for them. So add a prickly pear to your garden to help with the changing climate. And keep in mind that prickly pear jam is delicious!

Our 8 most popular newsletters

  1. Best and beautiful native shrubs for extreme heat
  2. Five fragrant plants for your garden
  3. Where to get free or cheap trees for your garden
  4. Six distinctively different landscapes to replace a lawn
  5. Cover up that naked wall
  6. Nine trees to combat climate change
  7. Four desert trees good for soil, 4 toxic ones
  8. Plants that bloom even in mid-summer scorching heat

Visit my author’s site to see the books I’ve published.