Category: U.S. Southwest

Lonely Cactus and a Giant Plastic Fish

At a visit yesterday to the Tucson Botanical Garden I found three of my passions combined: gardening in hot dry climates, art in gardens, and picking up trash from public areas.

I’m going to start with the picking up trash part in this post. [Full disclosure: I am a member of a Tucson environmental group called Trashy Divas and twice a month we pick up trash in public parks and along side streets.] Now, back to the ocean debris art.

Ocean debris turned to sculpture

The TBG always has interesting sculpture on exhibit in and around its many, small demonstration sites for drought-tolerant plants. Sometimes the sculpture is small and suitable for a residential garden. Other times the art is large — the ideal size for a public garden.

The fish at the top of this page, Priscilla the Parrotfish, is one of several sculptures now on display at TBG and it is large. The large Jellyfish, which hangs near the entrance, is unnamed for now. TBG is running a campaign to name it. I voted for the name Bubbles.

Both these sculptures were created by an environmental group called Washed Ashore based in Bandon, Oregon. All the materials have literally been picked up off Oregon beaches, then cleaned and refashioned by artists.

A few steps away from Priscilla the Parrotfish at TBG is another figure, a Rockhopper penguin, a native of islands around Australia and New Zealand. Nearby in the trees are a group of smaller jellyfish in sizes suitable for backyard gardens. One wonders if any of the materials in this penguin crossed the ocean from Australia to Oregon.

Another bird sculpture in black and white is Sebastian the Puffin. As a work of art it must be close to 10 feet tall; in real life puffins are only 2 to 3 feet tall.

Here are close-ups of elements that have gone into these creations. The image on the left is some of the plastic trash that makes up Priscilla the Parrotfish. On the right is the foot of Sebastian the Puffin with California poppies blooming behind. Every bit of this debris was at one time bought by someone in a store for some purpose, used and then discarded–perhaps in the ocean or perhaps nearby in a waterway leading to the ocean.

Puffin feet

The lesson here: dispose of your plastic trash properly in a garbage can or recycling bin. As charming as these art works are, we do not need any more of them made from plastic debris.

On to the lonely cactus

From the 1950s through the end of the 20th Century, lawn was the landscape solution for builders of large developments in the Midwest and East Coast. Sow grass seed to cover the lot with lawn, then plant a very small tree or a couple of small shrubs and call that landscaping. Cheap and fast.

Here in the desert, developers have continued this “fast-and-simple” approach to landscaping around new homes, but with one big change: instead of lawn they dump a truckload of rock mulch and spread it all over the lot. Then plant a small cactus and very small tree and call that landscape.

So now there are solo cactus in front of homes all over the Southwest. In reality cacti look better when planted in groups and give a home a more established, upscale appearance. Adding a mix of larger rocks adds to the sense of a natural environment.The image below shows denser plantings of a mix of cacti on a berm–an artificial hillock. You can see another example of planting on a berm here.

But this is not to say that an all rock mulch garden can’t be beautiful as this newish Japanese-style garden at TBG demonstrates. But you will have to rake it every day to keep it looking good.

And finally, back by the butterfly house, there is a new addition to Tucson Botanical Garden: a garden flowers kaleidoscope. The tube the girl is looking through has been created with a kaleidoscope refractive lens. It was fun to look through as the bowl of flowers spun slowly around.

A final note: The Washed Ashore sculpture will be on display through May 18.

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. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

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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.

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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. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

Gates to hide secret gardens and courtyards

Summer heat has arrived and planting season is behind us in the Southwest. If your gardening urge is still strong, there are other additions and/or changes you can make at this time of year starting with landscape features — the walls and garden gates around your home.

In newer communities in the Southwest, grey concrete block walls on three sides of a property are pretty much standard. In Tucson, perhaps because of its long ties with Mexico and Spain, many homeowners–especially in older neighborhoods–go one step further and enclose the front yard to create a private, family courtyard. And with walls on four sides, the garden gate entry to this secluded area becomes a very important statement.

So be inspired by these photos. Some are of very expensive custom stuccoed walls with garden gates designed by artists. But there others that use standard, off-the-shelf elements and even one that falls within the do-it-yourself range. And a simple coat of paint on a gray block wall or iron fence can always bring new life to a desert garden.

Fearless color and custom gates

One would expect a Spanish Revival home behind this wall and custom garden gate, but actually the house looks more like a Craftsman home that has been painted dark chocolate brown with orange trim. The gate with its sunburst is clearly Arizonan, but not a visual barrier. Definitely no fear here–well, except for that coiled snake on the left.

Another orange/terra cotta wall, but with a far less elaborate–and less expensive–gate. It is an ordinary door, painted deep blue. The sugar skull design appears to have been routed out of a thin panel of wood, but using paint for the face would create a similar look. The lights on either side of the door have pierced clay covers. Privacy is clearly important to these homeowners. But where is the door bell? I’m not sure.

Three doors that are almost medieval. All three appear to be handcrafted with found or repurposed wood. And each says “Stay Out”. The small sign on the brown wood door with a lion knocker states that the person standing there is under video surveillance. I guess some people are friendlier than others.

Gates across your driveway

  • garden gate with giraffe

Driveway gates with decoration added. The teddy bear parade gives passers-by laugh, especially with the giraffe, far right, peaking over the wall. In the second photos, the actual gate to the house is quite open. And in the third image at another home, the trickster Kokopelli playing his flute guards the drive.

Less expensive and very Arizonan

An ocotillo branch fence — a tradition that goes back thousands of years. The indigenous people used ocotillo for fencing, as well as for “roofs” on their ramadas long before any Europeans showed up. You may be able to collect ocotillo branches yourself, or they are available for purchase at a few stores I found online.

Another use of ocotillo on a gate. This one, however, seems to be a hybrid of the medieval fortress gates and ones using natural materials.

Rustic and charming

This is a charmingly rustic, do-it-yourself sunburst garden gate. It appears someone dismantled an ordinary gate and inserted painted metal elements representing the Arizona environment: cacti, mountains and a sunburst. The wall has been artificially “aged” by incomplete exposure of the brick. Fun!

Painting a iron gate and fence purple gives a customized look to what is probably an off-the-shelf addition to this Spanish Revival cottage and garden.

True confession: I love this gate and wall. 100% found and repurposed materials aging naturally in the Arizona sun. And who knows what lies behind; it’s on the edge of a light industrial area. In the second image, it is apparent that the red door was once something else that looks as if it is from India. Repurposed on an entirely different continent!

One last comment: if your homeowners association bans front yard walls or if you prefer not to add one, see the 6 distinctively different desert landscape designs on this website. They range from woodland to dry creek bed. All are open to the street.

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

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3 trees for Fall color in desert, but beware

With the limited color range in gardens in hot, dry desert climates–usually shades of brown and muted greens–having a tree outside your window that blazes with reds, yellows and oranges in Fall is a happy choice.

(I have a warning for you about leaves turning yellow at other times of year…but more about that later.)

First, let’s look at 2 big, beautiful, drought-tolerant trees and a small one that signal the change of seasons with their leaves.

These drought-tolerant Chinese Pistache (Pistacia chinensis) trees are still young. When mature, they are excellent shade trees at 40 feet tall and about 30 feet wide. Every Fall their leaves on the male trees turn from summer green to yellow to gold to blazing red–often with all those colors on the tree at one time as you can see in the photo at the top of this post. The female trees simply turn golden yellow. Strictly ornamental trees, they produce small non-edible red berries.

  • Rio Grande Variety of Fan Tex ash tree

The ‘Rio Grande’ cultivar of Fan-Tex ash (Fraxinus velutina) in this photo is about 14 years old. Not only is it a fast grower, it can be ideal for summer shade and winter warmth, after the leaves fall and the sun shines in. Once established, it is drought tolerant. While there are other ash trees that grow well in hot arid gardens — for example, the very fast growing ‘Modesto’ ash–only the ‘Rio Grande’ Fan-Tex ash leaves turn gorgeous gold in Fall. Click on photo to see it in summer.

And a colorful Fall and Spring tree for smaller gardens

If you do not have space for a very large tree, consider planting a crabapple (Malus) tree in your garden. They grow to about 15 feet wide and 15 feet tall. While needing regular watering, the crabapple flowers beautifully in Spring and the leaves turn a lovely orange/red in Fall. See second photo for spring blooms. If you should decide to buy one be sure to ask what the Springtime blooms look like. Some bloom white, some pink, some almost red and some are single blooms, others doubles. And the fruit is edible as a jam or pickle when cooked properly.

Beware of some yellow leaves

You may notice that the leaves on one of your shrubs are turning yellow — but the veins stay green–and it isn’t even Fall. This is an indication of plant chlorosis due to problems with soil conditions, specifically iron deficiency. There are commercial treatments you can use, like Kerex or other iron chelates and other spray-on treatments. They work short term. But improving the overall condition and chemical balance in the soil should be your next step after spraying for longer term results.

Listen to Mother Nature

Mother Nature plants in Fall and so should you. By planting at this time of year when the soil temperature has cooled off, the shrubs and trees have the opportunity to develop deep roots over winter and are, thus, stronger plants when they start to grow above-ground next Spring.

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

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

So your garden died. What’s next?

While there are two ways to combat plant death-by-dehydration, it is probably too late for many in the U.S. Southwest, especially Arizona and Nevada, after a weeklong stint of record setting heat. (For those of you outside of the SW, there were high temperatures of 110-120F (43-48 celsius) for 8 days in a row and it continues.)

If you still have hopes for some plants in your garden you can do this:
1. Deep water plants more frequently than usual.
2. Hang shade cloth over your plants.

Realistically, however, dead plants — especially vegetables that were planted not long ago–are the new normal in Southwest gardens.

So what comes next?

For starters you can add those dead plants to your compost pile, so all is not wasted! And do not regularly fertilize any plants during summer months in desert climates. Even sturdy native plants are simply hunkering down and trying to survive until cooler weather arrives. Give them water, and in late summer, a tiny taste of fertilizer–that’s all.

Replanting right away is, obviously, not a good idea. Many gardeners now seem to be considering planting only natives when they replace what they lost this summer, but wisely they are waiting until Fall.

I’m thinking about pots on my patio overflowing with non-native Lantana (L. montevidensis) which seems to be able to survive almost anything and continue to flower.

Adios tomatoes and peppers

My vegetable growing experiment of this year will not be repeated. It has become a once-in-a-lifetime experience. I can buy organic veggies and support organic farmers while I eat healthy.

While I have stopped wasting water trying to help my sunflowers, tomatoes and peppers survive, I am still trying to help birds and other wildlife stay alive. I’d suggest that you do this, too.

Set out a shallow plant saucer filled with water and refill at least once a day. It can be a lifesaver for birds, insects and other creatures suffering from the intense heat and scarcity of water.

I’m not sure which creatures drink from this water source on my patio, but at least this Mourning dove has. You could also set up a trail camera to learn which wildlife comes to visit your garden.

Turning your garden into a kind of wildlife preserve may be the best use of that space as climate change brings hotter and dryer conditions. This extreme heat may not be the last.

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

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

4 desert trees good for the soil and 4 toxic ones

Recently Tucson’s Mayor Romero announced a tree planting goal for the City: one million new trees planted in the next ten years to help combat climate change. (That works out to 274 trees a day!) Homeowners are encouraged to plant one or more trees around their homes. But the number of tree choices for hot dry gardens runs into the dozens. So how to choose?

Trees related to peas?

In the hot dry gardens of the Mojave and Sonoran deserts homeowners should consider the benefits of planting these 4 trees that belong to the pea family. Why pea family trees? Because they take in abundant nitrogen (NH2) from the air and convert it to ammonium nitrogen (NH4) which gets added to the soil via bacteria-filled nodules on the tree roots.

So, not only do these trees do what all good trees do–provide shade and remove carbon dioxide from the air–they also help other plants beneath and nearby to thrive by providing nitrogen to the soil for nutrition.

You see this everywhere in untouched, natural areas, like this photo from the Saguaro National park: cacti and other plants growing right under and up through trees.

Food for the soil and plants nearby

First on the Good-for-the-Soil List: Mesquite (Prosopis). Among the most common varieties of Mesquite are Argentine mesquite (P. alba), Chilean mesquite (P. chilensis), honey mesquite (P. glandulosa), the screwbean mesquite (P. pubescens ) and velvet mesquite (P. velutina). The honey and velvet mesquites produce edible seeds pods that are commonly ground up into a flour for cooking. The screwbean is quite a messy tree. In size, mesquites range from 8 to 10 foot tall shrubs to 40 foot tall trees.

Mesquite tree prosopis
Mesquite alba in Las Vegas

They are super-easy to grow. On my short walk this morning I noticed dozens of young volunteer mesquite trees sprouting along neglected areas next to the street. If they are left alone, within a few years they will become trees with no help from anyone.

Trivia: in Australia and Ethiopia mesquites were introduced a few decades ago and loved the weather and land so much that they are now regarded as invasive pest trees because they are aggressively taking over grazing lands.

palo verde tree at Sunnyland garden
“Palo Verde Tree, Sunnylands, CA 2-22-14” by inkknife_2000 (11.5 million views) is licensed under CC BY-SA 2.0

Second on the Good-for-the-Soil list: Palo Verde trees (Parkinsonia florida), the Official Arizona State Tree. In Spanish the name means “green stick” with good reason. It is immediately recognizable by the green color of its trunk and nearly leafless branches. In Spring it bursts into bloom with brilliant yellow flowers and small leaves emerge, only to fade away quickly. While it does not cast much shade, it too helps other plants thrive by fixing nitrogen in the earth. The Foothill Palo Verde, which has a more yellow tinge to the trunk, reaches 20 feet in height. The blue Palo Verde can grow to 40 feet tall.

Acacia in bloom at Los Angeles Arboretum

Third, we have the Acacia tree (Acacia), which some claim should be knick-named the “Allergy Tree”. These fast growing Southwest natives love the heat and bloom with yellow powder-puff flowers in the spring that leave a pretty carpet of yellow pollen and spent blooms beneath them. Some also bloom again in the Fall. The larger varieties will reach 40 feet in heights and provide excellent shade, but there is one smaller variety suitable for courtyards.

Food for the soil and people, too
“Carob tree” by tree-species is licensed under CC BY 2.0

Fourth, and a little harder to find, is the Carob tree (Ceratonia siliqua). Not only does this Mediterranean native tree add nitrogen in the soil, it has pods that, when ripe, can be ground up and used as a substitute for chocolate. Be sure to read instructions online if you plan to do this.

Growing to a height of 50 feet carob trees cast dark, cooling shade. Unlike the previous three on this list, it needs some water year ’round. It is, however, on the suggested tree list in Tucson. For whatever it is worth, it is one of my favorite trees and Carob ice cream was very popular among the hipsters in San Francisco in the 1960s.

4 Toxic beauties

But not all trees in the pea family are good. There are some toxic trees in the pea family which are quite beautiful and are planted in hot dry gardens throughout the Southwest–and probably shouldn’t be. While they can fix nitrogen in the soil they are best NOT planted in a family garden because of the dangers they can pose.

The Golden Medallion tree
Golden Medallion tree in Tucson

The striking Golden Chain tree (Laburnum × watereri) is uncommon, temperamental, and all parts are poisonous. The brilliant yellow flowers hang down like long chains of gold, which is where the name comes from.

The Golden Medallion tree (Cassia leptophylla) is similar in appearance to the Golden Chain tree. Its pods are poisonous.

The umbrella-shaped Mimosa tree (Albizia julibrissin) with its pretty pink-white flowers has poisonous seed pods and a reputation for being invasive.

The small Texas Mountain Laurel (Dermatophyllum secundiflorum) is a shrub-like tree with lovely purple blooms that look like wisteria or lilacs. Its brilliant red seed pods are deadly poisonous.

For more information about trees suitable for hot dry gardens, go to our Leafy Trees for Shade page.

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

Quinces and Figs thrive in the desert. Make great jam, too!

In 2014 Quinces (Cydonia oblonga) were named the Fruit Tree of the Year by the California Rare Fruit Growers Association. Well, maybe rare in California, but here in Tucson quince trees have been growing since the late 1600s. Brought to this locale by Jesuit Father Kino, one of the first Europeans to the area, later travelers complained that the only fruit tree in Tucson was the quince, which is basically inedible fresh off the tree. It has to be cooked and then it is delicious as a jam. I’m sure the travelers were hankering for juicy Spanish oranges or crisp German apples–but no luck. In Tucson hard quinces were the only choice.

Two quinces fro Tucson Presidio
These two quinces were given to me by a docent at the Tucson Presidio. The are unripe, hard, fuzzy outside and have no scent. More modern hybrids have a smooth peel and are fragrant when ripe.

While I have seen plenty of pomegranates growing in yards around Tucson I hadn’t seen a quince tree until I visited the replica of the original Tucson Presidio where a quince tree is planted side-by-side with a sweet Spanish orange tree and a lemon. As you can see, it is loaded with quinces, which are drought tolerant, sun and heat-lovers that need good drainage. Online it stated that 2 trees were needed for pollination, but this solo plant seems to be doing okay by itself. One other thing to note about quince trees: they are covered with lovely white flowers in Spring. So if you are thinking about adding a small tree to your hot, dry garden, maybe a quince is the tree for you. (Or maybe a fig–see below.)

Quince tree at Tucson Presidio Hot Gardens
The quince tree at the Tucson Presidio.

While quince trees are naturally small, fig trees can become enormous, as this fig, below, growing in one courtyard of the Tucson Presidio demonstrates. And it does not take decades to grow to this size. This Presidio was built from scratch on a former parking lot and opened in 2007, so this fig (and the quince above) are no older than 12 years!

fig tree in downtown Tucson Hot Gardens
A huge fig tree in the courtyard of the Presidio in downtown Tucson

In addition to producing delicious figs to eat raw or cook into jam, fig trees (Ficus carica) have large leaves that cast a dense shade to create a cool oasis in a desert garden. The ‘Black Mission’ and ‘Brown Turkey’ are good varieties for the desert. Most produce two crops of figs per year and need regular watering, especially when the fruit is growing. If you intend to plant a fig in your garden, be sure to ask the nursery staff how large the tree is expected to grow. Smaller size fig trees can be espaliered along a wall. (I know. I did this in my garden in Las Vegas!)

Pomegranates on the ground at the Tucson Presidio.

Now a word about pomegranates, which I have written about before because they are among the easiest and most forgiving of neglect of any fruit tree in a desert garden. There are ignored pomegranates on the ground all over my neighborhood, as well as at the Tucson Presidio. But it looks like they are providing food for birds and animals. A good thing!

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

Plant white this fall for nighttime viewing next summer

Fall is the best time to plant in hot dry gardens. The soil has now cooled enough that the roots of new, young plants won’t die from being enveloped by hot summer dirt. And summer dirt can be really hot: up to 140 degrees F (60 degrees celsius!) in direct sunlight. At that temperature the roots “cook” and if the roots get cooked, the plant dies. So do your planting now. Over winter, the roots will have plenty of time to toughen up and spread deep into the earth before the heat comes back next year.

Now I have a few suggestions for what to plant this Fall for a White Garden for nighttime enjoyment next summer.

A famous garden reinvented for the Southwest

First a little background: the White Garden was “invented” by author Vita-Sackville West when she designed a garden room at Sissinghurst Castle in the U.K. with plants that only produced white flowers. It was a radical idea for that time, the mid-20th Century. In fact, the White Garden vaulted her into fame as a garden designer and horticultural columnist for the London Observer. (She was already famous–maybe infamous–for her personal scandals and novels!)

So borrowing her idea–although not the plants she used in cool, damp Kent in southern England–here is a slide show with a few plants to use in a White Garden in the American Southwest.

  • White roses
  • White crape myrtle
  • White yarrow
  • Japanese Privet
  • Pittosporum- very fragrant

In addition to these white flowering plants you could also include dwarf White Oleander, White Jasmine Vine, white Iris, or Texas Wild Olive. Be careful with the Texas Wild Olive, Cordia Broissiere, because the seeds are slightly toxic to humans. Birds, however, love them. Also take care with the Oleander, all parts of it are poisonous.

Plants with variegated or silver leaves can also add luminousness and be reflective in a nighttime garden.

  • Variegated Turf Lily
  • Artemesia Powis Castle

Even if you are not interested in a white garden room, adding white blooming plants to an otherwise color-filled or all-green garden brings a spark of interest and contrast to the other plants.

Full Disclosure: I have visited Sissinghurst Castle to see Vita Sackville-West’s garden rooms. The book she wrote about her gardening ideas, “Sissinghurst” is available on Amazon. Someone, not VSW who passed away in 1962, is posting on Twitter using the handle @thegardenvsw . The tweets, taken from her writings and accompanied by photos, are always very interesting.

A reminder for Fall: be sure to add organic mulch around plants in your garden and, if possible, dig it in without disturbing the roots. Also avoid using mulch that has peat in it. From what I read from U.K. gardeners peat retains carbon which helps slow climate change. Better for all of us for the peat to remain buried in bogs rather than scattered around our gardens.

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

Gardens walled in by color in historic old Tucson

By midsummer most of the plants in hot, dry gardens–with the exceptions of Lantana and Mexican Bird of Paradise–are muted desert green.  Desert style gardens simply look drab and dull  at this time of year. The plants are in survival mode until Fall.

xicn Bird of ParadiseMy first plan for this post was to focus on those two plants which bloom in full force in summer. It turns out that the Mexican Bird of Paradise (Caesalpinia mexicana or C. pulcherrima. ) is also known as the Pride of Barbados and Poinciana. And while it flowers in sunset colors, left, one variety has only yellow blooms. And as for Lantana, a least here in Tucson, these popular plants need some shade during the day or they will rush to bloom and make seeds.

But as I was driving around historic old Tucson neighborhoods looking for good examples of Mexican Bird of Paradise to photograph, I noticed that so many gardens were  filled with color. But not from plants.  Homeowners had taken an adventurous route with painted walls — both on their homes’ exteriors and the garden walls that surround them. The green colors of plants had almost become accents.

Yes, we all know that painting walls and homes can be quite expensive, but the colors can be inspiring. And, once painted, the colors last for decades.  No watering, no fertilizing, no replacing sick or dying plants required.

Here are a few of those colorful walls and homes.

multi color home
Why settle for one or two  when you can paint each wall a different color? Variations on this  shade of green seem to be growing in popularity. The terra cotta wall and beige are more traditonal–but not when used this way!

blue stucco garden wall
Blue garden wall with a pink painted house is a color combination I saw more than once. I wonder if the lights wrapped around the tree trunks are turned on regularly or only during the winter holiday season.

pink garden walls
There is a kind of subtle minimalism about the pale pink walls with just a few plants. The home behind the walls is a slightly darker shade of pink.

golden stucco garden wzll
The palm trees leaning over this golden garden wall are laced with bougainvilla blooms–a very clever idea while the palms are not too tall.

orange color stucco wall
Nothing shy about this chocolate brown painted home with vibrant orange trim and a matching wall. The desert plants in front of the wall seem to be accents now, but the agaves and barrel cactus will grow quite large in time.

green color house Tucson
While green is making a comeback as an exterior color, this all green home is really over the top. Maybe a subtler shade of green? Maybe tempering the green with an accent color? It is certainly non-traditional for a stucco home.

Our 8 most popular newsletters

  1. Where to get free or cheap trees for your garden
  2. Six distinctively different landscapes to replace a lawn
  3. Cover up that naked wall
  4. Five fragrant plants for your garden
  5. Nine trees to combat climate change
  6. Four desert trees good for soil, 4 toxic ones
  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting