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The mixed blessing of the U.S. Southwest monsoon for gardens

 

Desert Willow and agaves
This desert willow is surrounded by agaves in a Las Vegas garden. These plants receive no additional watering during the year. Both desert natives thrive on the meager water that falls from the sky.

Monsoon rainfall season has arrived in the Arizona, Nevada, California — all over the U.S. Southwest.  The infrequent, but intense, summer rains sweeping up from the Gulf of Mexico are, however, nothing like the drenching daily downpour of the South Asia monsoon that trapped that young soccer team in a flooded cave in Thailand. The danger here is of hikers being caught in a flash flood in a canyon or cars being swept away on a road.

 

On the other hand our summer rainfall cloudbursts can add life to your garden if you take steps to retain part of the water falling on your property.  (Except in Colorado. More about this below.)

1.  The simplest method to capture rain in your garden is to dig shallow circular trenches or basins around your trees and shrubs. The basin edge should be at least 3 feet from the tree trunk and not too deep. Be careful not to damage the root crown at the base of the trunk or the roots of the tree.

2.  While most flower beds are raised — 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 rainfall as possible. The organic material in your flower beds will also retain more water than ordinary desert soil.

3.  Another technique is to dig or drill narrow, deep holes–1 or 2 feet in depth–spaced apart in a circle around trees and shrubs just below the ends of the branches. These holes will fill with rain which will then seep into the soil. You may want to consider dropping coarse gravel or small rocks into the holes to keep them from collapsing. These holes are also good for deep watering trees and shrubs to encourage growth of deeper, stronger roots. And deeper roots mean more stability when winds howl across the landscape in Spring and Fall.

Now for the technique that is more expensive–it’s called infiltration–and it is a problem in Colorado. That State by law owns all the water rights within its borders and individual citizens cannot retain water on their property without permission from the State because it would be denying that water to another person downstream who may have already obtained water rights from the state.  And they actually prosecute people for this! IMPORTANT: THIS LAW IN COLORADO HAS BEEN CHANGED AND IT’S NOW OK FOR HOMEOWNERS TO HARVEST RAINFALL FOR USE ON THEIR OWN PROPERTY.

California has passed a law to encourage homeowners to build cisterns on their own property.

Okay…back to saving summer rainfall.

4. Infiltration involves digging a sizeable pit on your property which will receive water from rain runoff from your roof.  This means installing rain gutters and downspouts, which are uncommon on desert homes. The pit must be lined with a strong, 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”. If you decide to go this route, be sure to get a licensed soils engineer to draw up plans to avoid a disastrous collapse.

5. Now for the last suggestion: channel the roof rainfall through downspouts into 50 gallon (or larger) plastic containers. This is a modern variation on the old time cistern, a sealed and lined pit to hold water for later use. You can use the water for irrigation later. 

And in between summer monsoon downpours remember to water your plants in pots. They are like animals in a zoo: you have to feed them every so often and water them daily.

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

Hanging vertical gardens: a quick and not-too-dirty way

Succulent
The first succulent I ever bought. Love the colors.

It is too hot for outdoor gardening now so I decided to write about hanging gardens.

Hanging gardens usually evoke one of 2 images: the moss-lined baskets with macramé hangers that were planted with common house vines and hung from living room ceilings back in the 1970s…

Or the legendary and long-vanished Hanging Gardens of Babylon where palm trees and other plants grew on terraces and rooftops in scorching hot summer weather in what is now Iraq.  (Their irrigation system must have been terrific!)

These days there is a third option: smallish succulents planted as a vertical garden to hang on a wall inside or out. I love the look of these—almost like abstract art in many shapes and shades of green and pink. Searching on the internet, however, I was more than slightly shocked to see that the Pottery Barn is selling vertical succulent gardens. And the cost? $269. On Amazon I discovered a beginners hanging pocket garden–no plants or soil included–for much less.

Well, what if I do it myself, I thought.

After reading a post about how to make a vertical succulent garden—making a framed box, installing a metal grid, adding cactus soil, planting about 50 or 60 tiny succulent buds (which can be purchased online for under $20) and then waiting for a couple of weeks or more for the roots to take hold and replanting if the roots don’t take hold—I realized that this wasn’t a route for me, either. (I am not a builder!)

Then I remembered two “hanging gardens” I had seen in downtown Los Angeles. One was on a north facing wall in Pershing Square and the other one a garden that rises at least 5 or 6 stories high in a parking garage.

Tower of plants Pershing Square Los Angeles
A vertical garden of lettuces and herbs in a parking garage in downtown Los Angeles.

The high rise garden was the brainchild of a local restaurant owner who wanted to go really local with the green stuff for his menu. For him local meant upstairs from his restaurant which was on the ground floor of a building with a parking garage several stories high.  If you look closely at the photo (sorry, it’s not a great photo, but I never thought I’d write about it) you will see lettuces and herbs stacked floor after floor. What a brilliant idea!  But apparently not one that would endure. Last time I was in downtown L.A. this parking garage garden was brown and clearly abandoned.

Which brings us to the vertical garden in Pershing Square in downtown Los Angeles which may provide an alternative to expensive hanging gardens. It was planted during the first rush to change all plants on Los Angeles public properties into drought tolerant plantings.

Drought tolerant plant wall Pershing Square (
Grasses, agaves and succulents in a vertical garden in Pershing Square, Los Angeles.

It is clear that two shelves have been installed in a niche in a wall and potted plants stacked densely on each shelf.  On the top is a row of grasses that dance in the breezes. It is clear that they are simply ordinary pots of identical types of grasses stacked side by side.

The next level down are the succulents, including 3 large agaves. I suspect that the agave pots have been tilted slightly sideways–about a 45 degree angle– so they will grow outward and the soil will still stay around the plant roots. Unlike the more common tidy, vertical succulent garden there are succulents and other plants trailing down, vine-like. And this vertical garden can be watered in place and does not have to be removed for watering.

Overall, using pots stacked side by side seems to be a much easier way to create a vertical garden but probably is best outside. On Amazon I found this vertical garden system that is self-watering and can be expanded from small space to larger inside or out. Perfect for the neglectful gardener!

The secret to success for all of these vertical gardens, of course, is density. Plant the succulents close together right from the beginning. Don’t wait for plants to spread out and fill in. You can always transplant them later if they become too crowded.

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

Should you plant a palm tree oasis in your back yard?  Maybe…or maybe not

For centuries palm trees have been symbols of comfort and safety whether

  • Spied in an oasis from afar in a scorching hot desert or
  • Standing tall as a “land-ho” sign after crossing a vast stretch of ocean or
  • Simply marking the beginning of warm weather country when traveling south in the U.S.

As symbols or signs, palm trees are great. I love seeing them lined up along The Strip in Las Vegas, and Arroyo Parkway in Pasadena and Canon Drive in Beverly Hills. But as for planting a palm tree in a residential garden…I am less enthusiastic.

3 Washingtonia robusta fan palms
Three Mexican fan palms.

Plant a Mexican fan palm (Washingtonia robusta) or a fruitful date palm (Phoenix dactylifera) and within a few years you have a tall, round brown column in your front yard. The graceful green fronds will have grown out of sight and cast very little shade.

The Mexican Fan palm has vicious thorns on its fronds and a prick from one thorn can cause an infection. And if your sky-high date palm produces fruit, the dates will drop and make a mess—albeit a tasty mess—in your yard.

But there are two and a half smaller palm trees that are more suitable for home gardens in hot, dry climates.

Pindo palm California fan palm

The Pindo palm (Butia capitate) has long fronds, like the date palm, but grows very slowly to 20 feet tall and about the same width.  It produces a yellow fruit that in some countries is turned into jelly or wine. It is the smaller palm in front in the photo. Behind it is a Mexican fan palm which is growing its way to 60 feet tall. Both planted at the same time.

Mediterranean fan palm Chamaerops humilis

The Mediterranean Fan palm, (Chamaerops humilis) as the name states, has fan-like fronds similar to the Mexican fan palm, but it is essentially a palm shrub, not a palm tree.  Many people trim the lower fronds off the multiple trunks to give this plant a more traditional “palm tree” shape. A slow grower may reach 15 to 20 feet someday. Its small, brown fruit is not edible.

Both these smaller palm trees can survive chilly weather, even a quick light dusting of snow!

sago palm cycad

And now for the “half palm tree”.  It is commonly called a sago palm, but it is not a palm at all. This low growing cycad is closely related to evergreen pine trees. It can be an attractive addition to a palm garden oasis and grows really s-l-o-o-o-w-l-y. Be sure to plant in a backyard; thieves steal them from front yards regularly because they are very expensive plants. Another note about the sago palm: its bright red fruit can be toxic to dogs and other small animals and is not good for humans of any size.

So even though palms like being planted in warm soil and can be planted in warm weather if watered sufficiently, consider how it will look in a few years. In my opinion, it is better to invest your money and time planting a fast growing Chitalpa tree (Chitalpa x tashkentensis).

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

Take the “screwdriver test”. Your lawn will thank you.

edge grass, agave, iceplant
Replacing a traditional front lawn with other drought tolerant grasses makes good sense.

Officially, the drought is over in California.  At least Gov. Jerry Brown said so.  But in Southern California and Nevada and Arizona and parts of Texas–even in New South Wales in Australia–drought conditions continue.

So many responsible homeowners are replacing their front lawns which we all now realize are nothing more than giant green sponges.  Keeping a lawn behind the house, however, can make a lot of sense, particularly as a play area for children.

And that backyard lawn needs regular watering.  But if you are not sure if you are watering your lawn too much or too little, here is an easy test:

Take an 8 inch screwdriver and push it into various places in your lawn about an hour and a half after you have watered.  If the screwdriver goes in easily, you are watering enough. You may even want to consider cutting back a bit on water.  If you cannot push the screwdriver all the way in, you need to increase the amount of water for the lawn.

Simple, right?

If you still love the look of a grass lawn, consider planting Buffalo Grass, a native grass of the American Plains. It has been hybridized in recent years so it now looks like a traditional lawn, rather than fodder for roaming buffalo herds.  It greens up in warm summer months, then goes dormant and brown in the winter. If you decide to go this route, be sure you plant plugs — not seeds. A Buffalo Grass lawn needs little or no watering at all.  Not much mowing either. (Note: this is not Buffelgrass, an invasive African grass that now threatens saguaros in Arizona.)

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

How to prevent death by dehydration with your potted plants

4 pots on patio
Tucked behind a pillar under a patio cover, these plants continued to survive in scorching summer heat.

I’m going to wear my “Captain Obvious” hat for this post–at least for the first 3 items.

First of all, keep those pots  containing plants in the shade. For example, under your patio cover, a big shade tree or on the north side of your home. Even then you may have to water the pot/plant more than once a day in a desert-like garden. It takes almost no time at all for hot and dry direct sunshine to suck all the water out of a plant. And if it windy, the dehydration happens even faster. At that point, the plant wilts and  it is highly unlikely that even generously watering the plant will bring it back.  It is doomed to death by dehydration.

Second: do not plant in metal containers.  A few years back many gardening magazines were touting shiny metal pails as suitable for plants. Some still do, but it is better not to do that in the desert or other hot, dry climate.The metal container heats up fast–even if it is not in direct sunlight–and “cooks” the roots of the plant. It is guaranteed to be another plant death by dehydration.

And third: avoid those shallow bowls that you find filled with plants at gardening centers as instant-gardens-in-a-clay-pot.  Only smallish succulents will survive for any length of time in them. There simply is not enough soil for roots to grow vigorously and absorb sufficient water to survive.

Now for a couple of positive suggestions, including a controversial one

Consider double-potting your plants. Place a larger pot around an inner one and fill in the space between with wood mulch or dried moss. Yes, I know it can be expensive to buy two different size pots for one plant, but it is effective. The wood mulch or moss acts as insulation. If you pour a little water into the space between the pots to dampen the mulch it increases the cooling effect. Do not add too much water, however, as it may end up flooding the inner pot from the bottom up, thus drowning the plant!

Now on to polymers, those water-retaining gel crystals, that are usually used in flower pots to help both cut down on watering and retaining water in the soil for the plants’ use. No question that polymers are effective. Recently, however, we heard a gardener advocate using water-retaining polymers in flower beds and in the soil around trees in a desert garden. It sounded like a good idea.

But a little online research revealed a preliminary study which indicates that polymers may break down in our native soil into chemical components that may not be good for plants and people. So while polymers may be helpful for plants in pots, do not start spreading them around your garden.

Making sure you have a lot of organic material in the pot is a better way to go. Soil rich with organic material absorbs water well and supplies nutrients to plants.

For basic information about plants in pots on our Hot Gardens website, please 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

Best fruit to plant in a hot, dry desert-like garden

pomegranate fruit on bush (

Shortly after moving to Las Vegas back in the 1990s I went on a hike with the Sierra Club in what is now the Red Rock  Canyon National Conservation Area. Our destination on this hike was an old abandoned ranch about 3+ miles from the pull-out on Highway 159 where we parked our cars. The ranch owners had walked away from the ranch years ago and turned it over to the Bureau of Land Management. (And the BLM had pretty much just ignored the place.)

So about 10 of us tromped off across the wide canyon floor. As a newcomer to desert hiking I forgot to bring water and it turned out there was no water at this old ranch. Just a weather-beaten house, a couple of fences that tilted and sagged…AND a row of pomegranate bushes still producing big red pomegranate fruit. These 8-10 foot high shrubs had survived for years with only the water that fell from the sky. And in Las Vegas, the average annual rainfall is about 4 inches! It might be a bit higher up in Red Rock Canyon, but not by much.

This was evidence that pomegranates grow well even under very dry conditions. And if you add a little bit of care and water they will do even better. Another plus: the leaves turn a lovely yellow in Fall and at Christmas time the fruit–if you haven’t picked it–looks like red ornaments in your garden.

So if you want a low-water usage fruit to harvest from your own backyard, plant a pomegranate. The ‘Wonderful” variety is an excellent choice and will do well even with neglect.

But don’t neglect taking water with you on a desert hike. I have always had water with me ever since that day.

Las Vegas Red Rock canyon (
This view is from the pull-out where we parked our cars. The abandoned ranch where the pomegranates were growing is up against those mountains.

See more suggestions about fruit trees for hot dry 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

Hello hot gardeners!

Aloe blooms in February
These South African aloes are among the early bloomers in a desert garden: their colorful spires rise above a fairly mundane looking plant in February.

Let me start by introducing myself.  My name is Carol Lightwood and I am a Master Gardener who earned my official state certification in Clark County, Nevada.  More specifically, in Las Vegas.

Shortly after completing the lengthy Master Gardener certification program in 2003 I launched the Hot Gardens website to help newcomers to the Las Vegas Valley understand the challenges of gardening in a desert climate. (ProTip: don’t plant pansies!)

Gardening conditions in the Las Vegas Valley and elsewhere in the U.S. Southwest states are horrible! Poor soils and, in Vegas, only 4 inches of rainfall annually. Since I loved having a beautiful garden, I began by planting Mediterranean plants that I knew  were drought tolerant from my years of living in Southern California. With considerable soil improvement, some care and water, most of them thrived in my enclosed patio garden. And I continued experiments with plants that could create the illusion of a lush garden with very little water.

For years I wrote a monthly newsletter about techniques and tips for best gardening results in a hot, dry garden. And hot, dry climates are expanding these days as the earth experiences climate change.The readership for the Hot Gardens site now includes gardeners from Australia, India, South Africa and the countries on the Arabian Peninsula as well as Spain, Canada and the U.K. So I decided to start giving gardening advice again and will be posting to this blog every so often.

I’d love to welcome you as a subscriber!  Sign up today.