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Don’t let rainfall escape. Capture it.

Saving rainfall for your garden

(This post was originally written about winter rains, but is now even more applicable for desert gardens in the summer of 2023.)

Rain has finally arrived in the American Southwest.  After an almost rainless summer which made our serious drought even worse, storms are now arriving one after another from both north and south Pacific. So now is the time to capture that rain water.

Use one or more of the following methods to keep water in your garden by encouraging it to stay on your property for future use or percolate down into the soil now rather than run off into the street.

Build basins

The simplest way to capture rainfall for the plants in your garden is to dig shallow circular trenches or basins around your trees and shrubs. The basin edge should be 3 feet or more from the tree trunk and not very deep. Creating a basin all the way out to the tree canopy’s edge is ideal. An inch or two depth will create a basin to hold a good amount of water while it sinks into the earth. 

Be careful not to damage the root crown at the base of the trunk. In fact, the basin shouldn’t start right at the trunk of the tree. You want to water to go to the smaller roots further out.

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 small basins in the center of the beds to capture as much rain as possible. Again, be careful not to damage the roots of your plants.

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

Infiltration–high priced or on the cheap

Infiltration, in its expensive form, involves digging a sizeable pit on your property which will receive water from rain runoff from your roof. This means rain gutters and downspouts must be installed. The pit must be lined with a strong but permeable material and have an overflow to channel excess water safely 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 but permeable material to help prevent the sides from collapsing into the holes while allowing water to escape into the root zone. Some people recommend using French drains, the drain pipes with holes, set vertically into the soil so they are mini-wells.

In the super-cheap version, really 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 winds howl across the landscape in Spring and Fall.

Add a cistern or rain barrel… or seven

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 a rain 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 certain critical engineering 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.

On the other hand buying a big plastic barrel or one of the large above ground cisterns–prices start at about $100 and go up depending upon the size–can be a quick and easy method to store the rainfall from the downspouts on your roof until you use it later.

Are cisterns illegal?

In Colorado and Utah having a cistern on one’s own property to collect water used to be illegal. But no longer. 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 in above or below ground cisterns to store water for use on the same property. In both these states, please check for specific local regulations.

Many other states, including Nevada and California, have regulations or are planning to enact them, about water harvesting and usage. California, for example, is encouraging water harvesting. To see if your state has regulations, go here.

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.

Happy Solstice – winter and summer!

My wish on today’s Solstice is that 2021 will be a better year for everyone! 2020 can’t end soon enough!

The light at the end of the proverbial tunnel is brighter now that the roll-out of COVID 19 vaccines has begun.

Now, you can make the natural world better this coming year by planting a tree that’s suitable for your climate to cast shade on your garden and home. The world continues to grow warmer and a tree will help cool it down a bit over the coming decades.

And, if you still have a grassy lawn, make 2021 the year you remove it and plant water-wise shrubs instead. Lawns are fine in wet climates, but an unwise use of water in hot dry gardens.

And, keep in mind that by planting long-living shrubs and trees you are also providing homes for Mother Nature’s other creatures, especially birds and insects.

May your garden thrive in 2021!

Carol Lightwood
Hot Gardens

The photo at the top of this page was taken at the Tucson Botanical Garden in December 2020.

Winterproofing palms to survive climate change

You have probably already seen one: a tall palm tree wrapped in strips of burlap which the owners hope will protect the tree during winter cold. In truth, this burlap bandage going from the ground to where the fronds begin is unlikely to have any impact at all.

There is, however, a proven way to “weatherproof” and protect palm trees in areas where winter temperatures sometimes fall below freezing–places like Palm Springs, Tucson, Las Vegas and London. That’s right–palm trees are now being planted and thriving in London in the U.K., a city that is further north than Seattle.

Climate change is definitely having an impact on gardens worldwide and on which plants will thrive where. While we think of palms as warm climate trees, they are now being planted in areas where cold, freezing winters are normal. And future changes in weather conditions are becoming more unpredictable, except that it looks like extremes of hot and cold will become normal.

The Proven Way to Protect Palms

So here is how to look at the situation: The best way–the proven way–to winterproof palm trees, which thrive in warm to hot weather, is to start off right and plant one of the palms that are also hardy–one that has built-in DNA resistance to winter chill. And you may be surprised at how many palm trees fit this requirement.

Mediterranean Fan palm for identification purposes
This Mediterranean Fan Palm (Chamerops humilis) in Las Vegas is shrub-like – not tall and stately.

Let’s start with my London friend’s palm tree which she was told by her local garden center was a “New Zealand palm”. I recognized immediately that New Zealand had nothing to do with it. Her palm was and is a sturdy, hardy multi-trunk Mediterranean Fan Palm (Chamerops humilis).

Ideal for small gardens, this short shrub-like palm has survived brief cold spells down to zero F. (-18 C.) And “brief” is the important factor; their survival depends on daytime warming after a night of chill. It has been 14 years since she planted it in a sheltered corner and, growing slowly, it still survives, and recently has even bloomed and produced fruit.

The next on this list of chilly-weather survivors is the Date Palm (Phoenix dactylifera), a native of the Middle East. It’s the tree you probably think of when someone says “palm tree”. Tall with long pinnate (rather than fan-like) fronds, this 75 foot high giant is very hardy. It has been known to survive and regrow after experiencing temperatures down to 5 F. (-16C.) Dates are, obviously, edible and the difficult-to-find Bahri dates are the very best. Unlike the chewy Medjool dates you buy in a store, Bahri dates are soft, delicious and taste like caramel.

Next is the Date Palm’s cousin, the Canary Island Palm, (Phoenix canariensis). While a few of these palms have reached a mature height of over 130 feet, that is uncommon. But they still are among the tallest palms. It will withstand temperatures to 20 F. (-7 C.) at least for a short time.  After a cold snap the fronds will turn brown and may very slowly regrow.

Tall palm trees native to the West

More common in gardens here in the West are two fan palm trees. The California and Mexican Fan Palms, (Washingtonia filifera and W. robusta), natives of Southwestern U.S. and northern Mexico, are also rugged, surviving cold weather as low as 18 F. (-8 C.)

Trimming the “hula skirt” of dead fronds off these trees may make them look a bit more tidy but that “skirt” offers the palms some protection, some insulation from severe weather. The downside of not removing dead fronds is that Mother Nature may do it for you during our fierce Spring and Fall windstorms. And falling palm fronds are very dangerous. The thorns on these fan fronds are also hazardous.

Like the date palms, the Washingtonias can reach heights of 60 to 100 feet, making them not particularly suitable for residential gardens although we see them planted around homes everywhere. After a few years’ growth they are more like architectural columns in a yard than trees.

Shorter palms for home gardens

A native of Mexico’s rocky Guadalupe Island, the Guadalupe Fan Palm (Brajea edulis) is a distinctive palm with a smooth grayish-brown trunk and silvery fronds. It grows about a foot a year to a mature height of only 25 feet tall, ideal for a residential garden. It flowers in summer from long drooping stems and the blooms are fragrant. Because it is a native to a small island with variable weather conditions, it tolerates heat, wind and drought, and it is one of the hardier palms, to 18 degrees F. (-7.7 C)

Pindo Palm (Butia capitata) , a native of dry South American savannahs, is another short palm, growing only to 20 feet. In Florida where it is popular in home gardens, it is known as the Jelly palm because people make jelly with its fruit. It tolerates temps as low as 5°F (-15 C) In this photo a very young Pindo palm was planted at the same time as the Washingtonia behind it. They have very different growth rates.

Originally found in high altitudes in China, Japan, Myanmar and India, the Windmill Palm (Trachycarpus fortunei) is a semi-dwarf palm with windmill-shaped fronds. Slow-growing to 15 feet tall, this tree loves our summer heat but will withstand winter temperatures of -10F (-23C).

My favorite fails the chill test

My favorite is the graceful Queen Palm (Syagrus romanzoffiana) a native of South America commonly planted in Southern California. It does not do well at all in cold weather. While I’ve seen it planted in hot dry Palm Springs, but with the weather uncertainty stemming from climate change, it may not survive there at all, except in a local micro-climate. Nearer the California coast, it grows beautifully and is ideal for home gardens.

And finally…

If a freeze comes and your palm tree ends up with browned fronds, do NOT remove it right away. Give it a few weeks or even a month or two of Springtime weather and it may very well produce green fronds again. And if you have to replace it in the end, choose one of the palms on this list.

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

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

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

Frugal DIY gardening tips for Fall planting

For thousands of years frugal gardening was the only way to garden. Instead of buying starter plants at a local nursery or garden center, people planted seeds they had collected and saved during the previous harvest. Or swapped seeds and cuttings with friends and family. Or divided their own existing plants.

They didn’t buy mulch or composting equipment from those Big Box garden stores either. For century after century they created soil amendments themselves or did without. All gardening was do-it-yourself gardening.

This thrifty approach still works in the 21st century and may be more important than ever, especially for those of us whose gardens scorched right down to the bare earth during the relentless heat this summer. Replacing the plants that died as well as introducing new ones may be what you are facing this Fall. And the expense can be shocking. You may even have moments when you think: Buy groceries? Or buy for the garden?

So here is what to do to create a money-wise, water-wise garden this year.

Your Library is Your Frugal Gardening Friend

Hundreds of public libraries from coast to coast have turned their old card catalogs into bins containing packets of free herb and vegetable seeds. The seeds are most commonly collected locally and packaged in carefully labeled plastic bags by volunteer gardeners. Because the seeds come from their own gardens you know that they should thrive in your climate.

seeds in library card catalog

If your local library does not offer this service, ask them to start one of these “seed banks”. Master Gardeners or members of gardening clubs may be willing to help launch this free seed service.

There are also free seed swap services online. I haven’t used any of them, so I won’t make a specific website recommendation. If you use one, keep in mind that seeds that thrive in one location may not in another, for example, in a hot dry garden. It’s best to find local seed sources.

And DO NOT plant any seeds that come from China or other foreign countries. Don’t even put them in the garbage. Destroy them or turn them in to the US Dept. of Agriculture.



Multiply by Division

Plants that grow from bulbs, corms or rhizomes, which are basically fat roots, can be easily doubled or tripled by dividing them after they have finished their growth season. Note: In most U.S. Southwest climates, it is not necessary to dig up and store these over the winter. Leave them in ground year ’round unless your garden experiences hard freezes.

Among the easiest to multiply by dividing is the drought-tolerant Bearded Iris (Iridaceae). Every 3 or 4 years simply dig up the rhizomes, trim the leaves back to about 5 or 6 inches, then cut the rhizomes apart with a sharp, clean knife. Allow the rhizomes to dry for a couple of weeks, then shallowly replant in late September or October. Don’t wait until Spring.

lily of nile canna lilies
Canna Lilies and blue Lily-0f-the-Nile Agapanthus.

When you divide Canna Lilies (Canna indica) there’s no need to dry out the rhizomes for weeks before replanting, but do wait until it has stopped blooming and the leaves have died down before you dig it up. After you’ve cut the rhizomes into pieces each with a short length of stem attached, let them sit for one or two days. Once the raw cut side has scabbed over you can replant.

Daylilies (Homercallis) and  Agapanthus also lend themselves to being divided. Again, dig them up, divide the large root ball clumps and replant. No long drying out period is required. You should do this every 3 to 5 years to encourage these plants to keep blooming beautifully. After replanting be sure to water them frequently until they are established.

Cutting it up

Take cuttings of your favorite lavender and replant. Bees will thank you!

You can multiply many shrubby perennial herbs, like salvias, rosemary, thyme, lavender, marjoram and oregano simply by taking a 4 to 8 inch long cutting of a stem with two to four leaves attached, then putting that stem in a pot of natural soil from your garden or use commercial potting soil mix. I prefer to mix native soil with potting mix. Take the cutting from fresh new growth for best results and keep the soil damp until ready to transplant into your garden.

You can also take cuttings from your favorite Geranium (Pelargonium) and simply stick them into a pot of soil or potting mix. Keep the soil damp and — voila — you will have vigorous new geraniums in bloom next summer.

Garden Shows mean big savings on uncommon plants

Because people who belong to specialty flower clubs and garden clubs usually cultivate rare and uncommon varieties of plants, at their plant sales you are likely to find unusual hybrids and colors to add variety to your garden.

Check out nearby botanical gardens, too. They often have ongoing plant sales to help support their operations.

Because of Covid-19, however, this is not a good year to hold a neighborhood plant swap in your front yard or driveway. Garden club sales and Botanical Garden events may also be cancelled because of the pandemic.

Not So Perennial

santolina and petunias
The short-lived Santolina (Santolina incana)
with petunias in a flower border suitable for a
hot, dry climate.  The annual petunia will not
last long in hot summer weather.

Now many of these plants are ones we think of as “perennials”, but perennials are not really perennial. They don’t last forever. Over a period of 4 to 10 years you may have to replace every perennial in your garden so DIY frugal gardening can be a real budget saver.

Some perennials don’t even last that long. One of our favorite plants for a perennial flower border in a hot dry garden is the Santolina. I love its brilliant yellow ball-like flowers but it rarely lasts more than 2 or 3 years and then must be replaced to remain beautiful.

And Finally: A Wake Up Call

And remember, it’s best to plant in Fall when the average daily temperature falls below 90F (32C). After all, that’s when Mother Nature plants her seeds. And plants that survived this summer’s blistering heat and have been in summer dormancy are now waking up and they are hungry. Feed them well in the next few weeks so they will be strong and not need replacing next year.

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

Saving a garden in relentless heat

As of today Tucson has suffered under daily high temperatures over 105F (44.5C) for 39 straight days. And the TV weather lady tells us these conditions will keep on going. No monsoon rain relief in sight in this part of the Sonoran desert. A friend in Las Vegas tells me it is as bad up there in the Mojave desert.

While this persistent heat is awful for humans, we can take shelter in air conditioning. Plants in the garden, however, cannot. So, what to do to help your plants survive this–or any other–extended period of heat?

The first thing that may come to mind is to increase watering the garden. Sadly, deep watering plants may or may not help. With day-after-day of temperatures of 90-100F+, some plants, particularly non-desert plants, cannot absorb water faster than it is evaporating through the plant’s leaves. Death by dehydration results.

Here, however, are 3 ways to help your plants survive until Fall.

Shade Cloth is a quick remedy

tucson tree under shade cloth
Photo Copyright by Tiffany Weerts 2020. An improvised shade cover in Tucson during a long hot spell.

Shade cloth is a fast solution for plants that appear to be suffering from heat exhaustion. You can buy it today, hang it up over vulnerable plants or borders in your garden and the protection starts immediately even if you have to just tack it up in a temporary make-shift way. Shade cloth comes in variety of weights and with UV protection.

Double pot to cool roots

For the plants that are in pots the heat and afternoon sunlight can be especially brutal. Placing pots where they will be in shade for most of the day is a recommended, but that may not be enough. Again, the problem is death by dehydration–water evaporating too rapidly through the leaves and from the potting soil. Compounding that problem is that terra cotta and metal pots heat up and can “cook” the roots.

Keeping potted plants in shade can help them survive, but double-potting increases the likelihood of the plants surviving summer heat.

However, one way to help your potted plants survive on the patio in summer is to set each pot in a second, larger container. Then put an insulating layer of dried moss or coarse organic mulch between the two pots. This will keep the inner pot cooler and protect plant roots from sizzling heat. You may want to try to keep the insulating layer damp–but beware of soaking it because the water could pool inside the outer pot and soak up into the inner one. You could end up drowning the plants from the bottom.

Consider using one of the newer plastic pots as your outer pot. They are far more attractive than they used to be and conduct far less heat than terra cotta pots. The insulation may also be helpful in winter, if you live in an area where it freezes in winter.

Controversial polymers

Polymers, those water-retaining gel crystals, are frequently used in flower pots to help cut down on watering and retain water in the soil for the plants’ use. This isn’t an instant solution, but polymers can help over a longer term–like all those hot days ahead of us here in the Sonoran and Mojave deserts.

Recently, however, we heard a gardener advocate using water-retaining polymers in flower beds and in the soil around trees.  It sounded like a good idea — particularly in a climate where water evaporates out of the soil so rapidly.

But a little online research revealed a preliminary study which indicates that polymers may break down in our native soils into chemical components which may not be all that good for plants and people. So while polymers may be a great solution for flowering ornamental plants in pots, stick with adding organic amendments, such as crushed pecan hulls or finely ground wood chips, to your garden’s natural soil to increase its water-retaining ability. Moreover, organic amendments add nutrients to the soil, which polymers don’t. If you would like to review the research yourself, to go Google and search for: “Polymers Gardening.”

And if the heat kills most of your plants–which is happening in many gardens here in Tucson now–you can replant in late September or early October.

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

What NOT to plant for fire season

I have always loved what I call the “Tucson Gardening Style“. No broad swathes of grassy lawn browning in the sunshine. No water-guzzling attempts at English flower garden borders limp in the heat. Just native plants left where they were growing before any house was built: prickly pear cacti squeezed side-by-side with creosote bushes and saguaros and agaves and chollas and mesquites. And most of the time these Sonoran desert natives grow right up to the side of the house.

But on June 5th, after the Bighorn wildfire burst into life north of Tucson, this native plant gardening style suddenly seemed less charming and more threatening.

At first the Bighorn fire was just billowing smoke high up in the Santa Catalina Mountains. By June 9 when I drove around northern Tucson to to take photos for another blog, I began to realize an inferno would result if this fire reached down into the upscale Catalina Foothills neighborhood which had only hours before been designated as a threatened evacuation zone.

As I took a few pictures I also realized that in California, where I used to live, the “Tucson Gardening Style” would bring the fire service knocking at the door armed with chain saws and big fines. The law in California is that there must be a 100 foot cleared open space around a home and it is aggressively enforced.

There is, however, such a live-and-let-live “Nobody’s going to tell me what to do” outlook by many Arizonans that it is unlikely that type of regulation would ever be passed here.

Okay, while I live in Arizona now I’m going to ignore local attitudes regarding plants because wildfires happen here and throughout the Western United States. Here are some recommendations about garden plantings to help prevent your home turning into an pile of burnt rubble from an urban or wild fire.

First, clear plants away from the sides of your home and other buildings. Don’t let any shrubs or trees touch or almost touch a building. If the plants catch fire — even if ignited by sparks from a neighbor’s BBQ instead of a wildfire–your home could burst into flames before you even notice it.

While many trees suitable for hot dry climates have oily leaves, the Australian-native Eucalyptus trees are among the worst. Sure, they smell so good, but they are 50 foot high torches just waiting for a little spark to light them. As much as they seem to be great trees for hot dry climates (fast growth, low water usage, lovely dappled shade), they are not. As witness: the massive fires racing through the Eucalyptus forests of Australia in recent years.

I have also seen palm trees burning as 50 foot high torches in Los Angeles during an urban fire, but while embers fell from the palms, they did not seems as potentially dangerous as a flaming eucalyptus with its branches whipping in the wind casting sparks all over the area.

For very a different reason don’t plant a Cottonwood, a major water-sucking plant. Again, it is a fast grower, but will guzzle every drop of water in the ground around it and deprive other plants of water, leaving them tinder-dry. Cottonwood roots will also invade your plumbing and septic systems.

One grass is on the Do Not Plant list:

Buffelgrass (Cenchrus ciliaris L., or Pennisetum ciliare L.) is often called white fountain grass. An African native, it grows and blooms quickly, then dies back to leave dry, quick-burning fields waiting for a lightning strike to start burning. This grass, a threat to native plants including Arizona’s famous Saguaro cactus, has been mentioned as a key factor in the origin of the Bighorn fire. You can view a new webinar on the topic of buffelgrass damage to the Saguaro National Park .

Red Fountain grass does not spread wildly like White Fountain Grass. And it looks lovely when the wind blows.

Instead of Buffelgrass, consider Red fountain grass (Cordyline) which is less invasive and stays where it is planted. The much larger South American-native Pampas grass (Cortaderia selloana) will also stay where it is planted in a desert climate, but not if there is a pond or stream nearby. In that case it becomes invasive forcing out native plants.

Now onto something more positive. While the evidence is anecdotal, a few homeowners have sworn that their huge water-logged agaves saved their homes during a wildfire. I’ve seen the photos and the agaves encircling the homes look as if they have melted, but the houses were spared. It’s important to note that there was a cleared space between the house and the agaves and beyond the agaves, too.

As for planting any trees or agaves, wait until fall. It is too hot now and there is a great risk that anything you plant will die of heat at this time of year no matter how much you water it. Don’t let the landscape guy tell you otherwise!

The Bighorn fire is still burning on June 19th, but because of a wind shift, it is moving northeast, away from Tucson proper. A photo of it taken yesterday is at the top of this post. According to reports over 3,000 Saguaros have already been destroyed, but–happy news–most of the wild animals in the fire path, including baby mountain goats, have escaped. And there has been no loss of homes or human life so far.

Here is what happens to an SUV when the Forest Service makes a Phos-Chek drop. It’s that red stuff fixed wing airplanes drop on the edges of fires.

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  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

Adios Lantana. Hello potatoes!

NOTE: this is somewhat apocalyptic, but there is a bit of humor at the bottom.

Until recently, prepping for the apocalypse seemed to be a fringe activity. It kept a few people busy stashing fairly expensive survival gear in their basement survival shelters. Some preppers even got reality TV contracts which probably helped pay for those high priced guns and goodies.

Since the arrival of the coronavirus, however, and especially since the shut-down of midwest meat packing plants, more and more people–me among them–are considering planting a “survival garden”. Prepping now seems a realistic activity as significant disruption of the food distribution channels suddenly is a real possibility. It’s a complicated issue but here is an article that explains how food disruption is already happening in the U.S. and around the world.

tomatoes on vine

Now I’ve never been a big supporter of homeowners trying to grow vegetables in a hot dry desert-like climate. It takes a lot of effort, water, raised beds, shade cloths, soil amendments or even the entire replacement of lousy alkaline desert soil to grow veggies in a hot dry garden.

Even with all that I’ve heard disappointing tale after disappointing tale from gardeners who tried to do it. The costs are very very high, especially when calculated at the total dollars spent to produce each tomato or cantaloupe or bunch of spinach.

I’ve always thought: it’s better to support organic farmers by buying their vegetables at the grocery store. As we all know it costs a great deal of money to grow organic vegetables which is why they are more expensive than regular store-bought veggies. Even then, vegetables and fruits from organic growers are less expensive than growing your own in your backyard.

I’m beginning to rethink this.

root vegetables

Here is what I am going to do: rather than going the big raised bed or full backyard garden routes, I decided to start small and checked on Amazon to find grow bags, especially potato grow bags. My reasoning is that people–think of the Irish back in the 1700s and 1800s–lived almost entirely on potatoes. Not a balanced diet, but nutritious enough to survive for awhile.

Other below-ground vegetables, including carrots, parsnips and onions, as well as herbs and even tomatoes can be raised in grow bags.

potatoes on soil dirt

Then today I learned this lesson: what grows reasonably well in one hot and dry location won’t live in another. Summer, I discovered, is not a good time for potatoes in Tucson. Sweet potatoes are a possibility, however. I’m going to have to do more research on what vegetables might grow in Tucson’s version of a hot, dry climate with its monsoons. Cantaloupes and squash are possibilities, I think. But when the weather cools I’m going to plant potatoes. Yukon Gold potatoes to be more specific.

Now I’m not advocating that you start a “survival garden”, but it seems to me to be worthwhile considering because now, more than ever in my lifetime, the future and the food supply seem very uncertain.

I’m not, however, going to remove the Lantana in my front garden and plant potatoes instead. Grow bags on my backyard patio are going to be my “survival garden”.

OK Here is a funny for you.

For art lovers: Tussen Kunst & Quarantaine (@tussenkunstenquarantaine) • Instagram photos and videos

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  7. Plants that bloom even in mid-summer scorching heat
  8. Follow 90F degree rule for planting

Is it an attractive weed, a native plant or tasty edible?

Rather than giving you gardening advice for March today I’m going to tell you about one plant, which turned out to be more interesting than expected.

Moving from one desert, the Mojave, to another, the Sonoran, has meant that I am learning to identify many new native plants, among them, the Common Mallow (Malva neglecta). The name “neglecta” is so apt because my neglect has resulted in massive growth of this plant in a narrow yard beside my house.

Surprise! Not a native

Yesterday afternoon, after I wrote the headline for this post and the paragraph above, I discovered that while this variety of Mallow is as common as dirt here in Southern Arizona it is not a native at all. Not even a native plant of the Western Hemisphere. It’s origins are in Egypt, probably in Nile marshes. That makes sense because the leaves are so large and dark green which is very untypical of desert plants, for example, the Desert Mallow (Sphaeralcea ambigua).

mallow plants growing wild

Since like most of you I am home all the time because of COVID-19, I tentatively planned to start removing at least some of this mallow mini-field.

But after learning more I’m not sure what to do about it. If anything.

How to eliminate weeds 3 ways–or not

Should I listen to the Round-up folks who claim to make it easy to exterminate with a quick spray? (We all know about Round-up so I won’t write more about this option.)

Or how about going extreme like some here in Arizona and blowtorch the weeds–uh…the mallow? You read that right: some gardeners here use flaming blowtorches on weeds because that will kill the seeds, too, even ones that are under a layer of gravel. No blowtorch among my garden tools, so that eliminates this one.

Then came the suggestion of a third way for weed elimination. A couple of gardeners recommended mixing 55% vinegar with water and a dash of liquid soap, then spraying it on the weeds. I am tempted to test this idea–someday when I feel I can risk using the vinegar in my emergency pantry for something other than salad dressing.

The next option is re-wilding

Inspired by a British gardening movement to let wild native plants thrive along roadsides and in city squares, should I simply let my Mallow continue to grow? In the U.K. a Back-to-Natives trend is growing (pun intended!) in an effort to support other native species, including bees, badgers and other wildlife. I wonder if here in Arizona, rattlesnakes and scorpions may find the mallow mini-field a friendly habitat.

Or should follow the advice of two forager friends who pick leaves of dandelions and mallows for their salads?

Behold the multi-use vegetable

mallow blossoms and seeds

They have assured me Mallow is edible, that its seeds tastes like its cousin, Okra (Abelmoschus esculentus).

“Use it in a salad or cook it to thicken soups like gumbo,” they tell me.

Then they go on to add: “It’s really high in Vitamins A, B, and C as well as calcium, magnesium and potassium. Like kale.”

Like kale?

No thanks. (And please don’t reply with a list of all the health benefits of kale. Broccoli, which I love, also is vitamin-packed.)

This morning I was informed by yet another Arizona gardener of one more use for Common Mallow’s big, soft leaves: as toilet paper! Eureka! That’s the solution to the hoarding problem. Plant Mallow now and have a lifetime supply of t.p.

And if the coronavirus situation and the hoarding get worse, maybe I’ll start picking the Mallow leaves and selling them on a street corner as a multi-purpose vegetable for kitchen and bathroom.
Respect the weeds. Stay safe. Happy Gardening.

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  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

Composting is an unnatural act…

Well, composting is unnatural in a hot dry climate where plants produce small leaves with waxy or oily exteriors, where grassy lawns are few and far between and where the air is, more often than not, dry as a bone.

Those are things that are antithetical to the natural composting that occurs in cooler, more forested zones where big leaves and/or lots of pine needles, weekly grass clippings from the lawn, and damp air make composting a normal part of the environment and is fairly easy for a gardener to do.

So because it is not a natural function in a hot dry climate, I’ve never written about it.

During this last month, however, I received an question about it so if you want to start composting, even though you are living in a hot dry climate, here is some advice.

First: the good news about compost. Compost is food for the soil. It loosens the soil hardened by heat and dry air and makes it easier for plant roots to grow deep. It enriches the earth with long-lasting nutrients. Used as a mulch on flower beds it can be protective.

But compost should not be used in place of fertilizer. Its carbon to nitrogen ratio is too unstable, too unpredictable to count on as a fertilizer. In fact, if the compost process isn’t fully complete, the compost may suck nitrogen right out of your soil. Compost that is “complete” is crumbly, not smelly, dark brown or almost black and will, very gradually over years, release some nutrients to your plants and help balance the pH in your garden.

composting food waste

Now to get started the first thing you are going to need is a place or a container to hold the garden and kitchen waste you want to turn into compost.

From left: beginning, middle and done with composting!

When I had a compost heap in my Santa Barbara garden, it was just that, a heap of grass clippings and leaves in the far corner of my backyard that had been started by the previous owner. If I was doing it again, I would have either set up attractive wooden bins or put everything into metal canisters that could be turned. (Live and learn!)

Then begin by adding biodegradable stuff, such as grass clippings, leaves, coffee grounds, sawdust, faded flowers, dead annuals, and even newspapers torn up into little bits. You need a mix of one part green stuff to 3 parts brown stuff for the best composting process. For green stuff you add things like grass clippings; brown stuff are things like chopped straw or old dead dry leaves.

Next, toss in a shovel or two of your native soil to jump-start the process. NO need to buy compost bacteria or fungi starter. Your native soil has what you need.

And dampen the whole thing. Don’t soak it. Just keep it damp like a sponge that has been wrung out. This is especially important in our dry climates. You may have to dampen it daily…or more often. If possible, keep your compost in the shade so it won’t dry out as quickly.

Be sure to turn it regularly so the decomposing process continues on all materials, not just those on outside. When you turn it you may discover it is warm or hot in the center. The center of the compost bin may heat up to 130F, which should kill all the wild seeds that ended in it. If it becomes too hot, that is a sign of excess carbon and you should add more green stuff, like grass clippings or weeds you pulled from your garden.

raccoon by wall

Now about food waste. If you are composting in a container, especially a revolving one up off the ground, toss in all the food waste you have. BUT, if your compost “bin” is actually a compost heap you may find wild raccoons and other hungry animals visiting it. They love those old apple cores, orange peels, rotting pumpkins, bananas and other food leftovers.

Do NOT put meat or dairy in your compost pile. It will not decompose quickly, will smell hideous and may attract vermin or dangerous bacteria to your garden. Also avoid leaves of oleander, they are poisonous. And avoid adding eucalyptus and salt cedar leaves.

I strongly recommend acquiring some type of plastic or metal compost bin. Some cities offer residents free compost bins, so call your local government to see if you can get one or two for free. There are also several on Amazon that look good, including a pink compost bin. One even claims to be able to make compost in two weeks! That’s fast! Composting usually takes months. Happy composting!

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