Every gardener loses plants — it’s an inevitable part of gardening. Each loss can teach you to become a better gardener, provided you understand what went wrong. Here’s a look at the 12 basic reasons desert landscape plants may fail to thrive and what you can do to prevent plant failure going forward.
When all goes well in my garden, I take it for granted and pat myself on the back for having a green thumb. đ¤ But when a plant struggles or dies, I blame myself and wonder what I’ve done wrong.
Thomas Edison famously quipped, âI have not failed. Iâve just found 10,000 ways that wonât workâ when trying to invent the lightbulb. And sometimes gardening in the desert can feel this way. There are many ways to kill a desert plant, but thankfully, there are fewer than 10,0000 and they fall into a dozen categories.
Hereâs a look at the factors that can contribute to the loss of a plant. I’ll start with those that you can do something about, and then finish up with causes that are outside your control.
âĄď¸ Be sure to check out the suggested reading at the end of each section to learn more about solutions to these problems.
#1 Water: Too Much, Too Little
Improper watering is estimated to be responsible for 90% of all desert garden failures. So it’s critical that you get this right.
Desert landscape plants can be killed by too much water or too little.
Too Much Water
Having all your plants on the same irrigation zone is a surefire way to overwater some plants, causing their roots to rot.
Simply being planted near irrigated plants is enough to do some desert natives and succulents in. We’ve all seen fat saguaros that are not intentionally being irrigated. But the owners are not taking into account that saguaros have roots that extend 100 feet in every direction and will suck up water not meant for them.
Too Little Water
It’s not uncommon for gardeners to lament, “How can my plants get too little water? I water every day!”
Most gardeners water too frequently, but give their plants too little water with each watering. When you give your plants a little bit of water at a time, the roots remain close to the soil surface, where the ground is hot and moisture quickly evaporates. Since roots follow water, plants watered this way develop shallow root systems.
Watering deeply is training your plantsâ roots to move downward, where the ground is cool and thereâs a reserve of moisture. Plants watered deeply grow robust root systems, making them more resilient to heat and drought and less prone to toppling over during storms.
The chart below provides a good starting point. Many gardeners are shocked to see how infrequently they should be watering.
How & Why to âDeep Waterâ Desert Plants
#2 Assuming Desert Plants Like “Full Sun”
You might be surprised to learn that very few landscape plants like all day full sun. Even many species of cactus and agaves appreciate some relief, especially in the afternoon.
Most plants sold at nurseries have a label that indicates a plant’s sun preference. Many say “full sun.” However, this usually means full sun where they don’t have any! A “full sun” label does not necessarily mean a plant will tolerate the “death star” sun of the desert southwest.
Before planting any plant in full sun, check to make sure it can tolerate full sun where you live. A good place to start is in our Desert Plant Library, which contains comprehensive plant profiles of over 150 popular desert landscape plants.
Why Even Desert Succulents Like Some Shade
#3 Wrong Plant, Wrong Place
We’ve all done it — bought a plant spontaneously and then struggled to figure out where the heck to put it! You may have then planted it where you thought it would look good and hoped for the best. The chances you’ll have put that plant in an ideal spot are slim.
So if your plant didn’t thrive, it may be because it was in a spot where its requirements — water, soil, light, temperature range, and other location considerations — were not met.
#4 Pests & Diseases
We share our gardens with critters large and small, and some of them can kill your plants.
Javelinas and rabbits will eat almost any plant if desperate enough. I was shocked to learn that javelinas eat entire prickly pear pads (including glochids!) and rabbits will nibble on ocotillo, one of the desert’s toughest plants.
There are many insects and diseases that can kill plants, too.
And if you suspect your plant has a pest or disease, identify it before trying to treat.
Your knee-jerk reaction should not be to kill any bug you see on a plant. Some are good guys in the garden while others become tomorrow’s butterflies. Using insecticides (even natural or DIY remedies) can harm beneficial insects as well as the pests.
Diseases can be caused by nutritional deficiencies or various infections (viral, bacterial, fungal). It’s important to know what you’re treating. You may do more harm than good with a shotgun approach.
The best thing you can do to prevent plant diseases is to keep your plants healthy. Stressed plants are more susceptible to pests and diseases.
Agave Weevil: Little Bug, Big Problem
Why Desert Plants Get Iron Chlorosis (& what to do)
#5 Garden Chemicals
You’d expect that commercial garden chemicals would be safe for your plants, but that’s not always the case.
Overspray from herbicides is one of the leading causes of witchesâ broom, abnormal growths characterized by tight clusters of stunted shoots or leaves.
Too much fertilizer, especially synthetic fertilizer, can cause fertilizer burn.
Sprays for treating insects or diseases can burn a plant’s leaves, especially when the temperature exceeds 90°F. This includes chemical sprays as well as natural sprays like insecticidal soap, neem oil, and various DIY home remedies.
Are The Weird Growths on Your Plants Witchesâ Broom?
Insecticidal Soap vs Dish Detergent: Which is Better?
#6 Planting in a Subpar Hole
You might wonder how there can be a wrong way to dig a hole! But here in the unforgiving desert, there are a surprising number of ways you can do it wrong.
Was your hole the right depth and width? Did you amend the soil? (Hint: you probably shouldn’t have.) Did you check for drainage?
Digging a hole properly is one of the most important things you can do to get your new plants off to a good start. Putting a plant in a half-baked hole will doom it from the start.
How to Dig a Hole in the Desert
#7 Planting at the Wrong Time
Not all plants should be planted at the same time of year. Most plants do better when planted in the fall, but some should be planted in the spring.
Only a few types of plants (i.e., succulents, citrus, palms) prefer to be planted during hot weather.
Learn what to plant when in the following articles:
What to Plant in Spring (Month by Month)
What to Plant in the Fall (Month by Month)
#8 Transplant Shock
Transplant shock is one of the fastest ways to kill a plant.
Most plants you buy were grown in greenhouses where their water, light, and temperature are carefully controlled. But all this pampering doesn’t lead to resilience. Imagine the shock of going from paradise to your desert yard!
Clearly, a new plant faces many challenges, but you can lessen its load and reduce transplant shock by planting it at the right time of year (see above).
And always let a plant acclimate for a week or so before planting. During this time, place it in a sheltered spot and water frequently. (Plants at garden centers are used to being watered haphazardly — often too much or too little.) Then gradually move it to a progressively sunnier spot. Wait for a good day to plant, ideally one of moderate temperature, little wind, and some cloud cover.
#9 Improper Pruning
There’s a right and wrong way to prune most desert plants. There’s also a right and wrong time to prune, depending on the plant.
Shrubs that are constantly sheared or pruned into balls, blocks, or other unnatural forms get woody inside and eventually die.
Here’s an example of ornamental grasses that were improperly pruned at the wrong time of year. They should have been cut close to the ground at the end of winter. Instead, they were cut into balls in the fall. (These are in my neighborhood, and sadly, they never recovered. đ˘)
#10 Stressed When You Bought It
Frustratingly, a plant can be stressed or unhealthy when you buy it. It’s not unusual for nursery plants to be root-bound or have girdled roots, to have suffered from stress, or to already have a pest or disease.
You can minimize the likelihood of buying a stressed plant by inspecting it for any obvious signs of distress before you purchase. And stick with small, local nurseries rather than big box stores.
#11 Extreme Events
While you can do your best to grow plants suitable for your area’s microclimate, you can’t avoid every possible eventuality.
I’ve lost plants to wind, hail, snow, heat waves, cold snaps, and irrigation system failures. (Why do irrigation systems always go down when you’re out of town?)
Summers are getting hotter and longer, and some plants succumb to the heat. (That’s even happening with native plants like our beloved saguaros.)
Monsoon storms are notorious for knocking down trees.
Losing a tree is traumatic enough, but the secondary effects can be even worse when your entire yard has suddenly lost its shade.
Heat Wave Survival Tips for Desert Gardens
How to Protect Your Trees From Storm Damage
#12 End of Lifespan
And finally, your plant simply might be at the end of its lifespan. While some desert plants are exceptionally long-lived — creosote can be thousands of years old! — some desert plants are disappointingly short-lived.
Some trees, such as many species of acacia, only live for 20 years or so.
Many perennials only live 3 to 5 years.
Agaves such as smooth agave (Agave desmetiana) or Octopus agave (Agave vilmoriniana) only live to be around 7 years old. You’ll know they’ve reached the end of their life when they send up their spectacular end-of-life flower stalk.
My Agave is Blooming â What Now?
A Final Word
Losing plants is an inevitable part of gardening. Every time you lose a plant, it can hurt, but you can use a loss as a learning experience that will help you become a better gardener.
Donât be too hard on yourself — weâve all had our losses.
When I lose a plant I remind myself that there are “no failures, only feedback.” These are wise words to live by in the garden… and in life.
Did you enjoy this article?
Sign up for our weekly newsletter
where you’ll find more great info on creating &
maintaining a beautiful, carefree desert landscape.
Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for over 15 years.
