garden in the desert with small tree and plants

Let’s face it. Hot summers are not surprising to desert dwellers. In fact, a typical garden with native and desert-adapted plants will weather intense heat with little fuss.

However, this summer has been one for the books and I’ve seen signs of heat-stress that I’ve never seen before. And yes, within my own garden.

Heat-stressed Rock Penstemon and Golden Barrel Cactus

I must admit that it’s been hard to see certain plants struggling in my garden and I know you may have similar feelings. So, why has this summer been so much more difficult than others?

Pink Trumpet Vine partially defoliated due to the heat

While it is normal to have several days above 110 degrees F., the summer of 2020 is one for the record books. We have experienced not just a couple of stretches of above-normal temps but, several long spans of infernal heat. Damage to plants is often cumulative. This means that the more days of above-average (or below-average) temperatures – the higher incidence of reaction from plants.

Take a walk outside in your garden. You will likely notice some plants that are yellowing, wilting, or have given up and died. However, you may also note that there are some that are doing well.

Why is that? Let me show you some examples from my own garden – the good AND the ugly.

Let’s start with the ugly:

New Mexican Fence Post cactus transplants

In March, much of my backyard was renovated. This included the addition of two separate plantings of Mexican Fence Post cacti. They are located along my back wall and as you can see, one is doing very well while the other makes me cringe when I see the yellowing.

Does the yellowing cactus need more or less water? No. Many succulents yellow in response to summer heat. Of course, this very hot summer has made it more severe. So, why the difference between the two?

The one on the left gets filtered shade in the afternoon from a nearby Palo Verde tree. You can tell that the one on the right doesn’t get any shade but full afternoon sun. In a normal summer, it would be normal to see some yellowing that will return to green once temperatures cool. I am hopeful that will happen. As plants age, they tend to handle heat stress better and as these are young, the stress was especially severe.

Signs of heat stress

In another area of my garden, I have Green Desert Spoon and Hardy Spineless Prickly Pear, which are very heat-adapted. Yet, they do show signs of mild heat-stress that I haven’t seen before. But, they will green back up in fall. Other plants that are struggling include Artichoke Agave, Gopher Plant, and Shrubby Germander.

I am thrilled that my young Desert Willow tree in this photo is thriving despite the heat. I have four others scattered throughout my landscape and all are doing just as well.

Here are some of the good:

Young Baja Ruellia (Ruellia peninsularis) doing very well. The neighbor’s Dwarf Myrtle isn’t.

‘Sparky’ Tecoma shrub (Tecoma ‘Sparky’)
Pink Muhly (Muhlenbergia capillaris). Will soon burst forth in burgundy plumes in fall.
Gold Lantana in full sun all day

Feathery Cassia, Purple Trailing Lantana, and Yellow Bell shrubs are also doing well.

Here are a couple of exceptional performers that get full, reflected sun:

‘Rio Bravo’ Texas Sage
Bougainvillea

There are still six weeks of summer heat ahead of us. So, what should we do for now?

  1. Be sure plants are receiving enough water. You may need to increase the frequency when temps are above 110 degrees.
  2. Don’t fertilize. Feeding plants simply makes them work harder to produce new growth when all they are trying to do is deal with the heat.
  3. Don’t prune away heat-damaged growth until September. While brown leaves are ugly, they are protecting the interior of the plant. Some pruning is recommended in mid-September, which I teach in my Shrub Pruning Workshop.

We don’t know if this summer will be an anomaly or the beginning of a new normal. But, instead of throwing in the towel, I invite you to do the following instead:

Take a stroll through your garden and take note of which plants are doing well and those that aren’t. If this is to be the new norm, it would be a good idea to add more of those that handle the heat well.

b

I am not going to make any major changes in my own garden. Most of my plants have done just fine in past summers. I’ll replace the few plants that died but am hopeful that next summer will be one with average temperatures. If not, then I know what plants have withstood the heat best.

Before we know it, fall will be here, and I for one, can’t wait!

What do you do when you spot aphids on your plants?

Do you reach for the nearest bottle of insecticide? Spray them off with a hose or remove them with your fingers?  

Believe it or not, sometimes the best thing is to do nothing.

So, is this something I learned in school? No. I figured it out by observing the plants in my first garden.

 
I remembered this early lesson when I passed by a severely pruned oleander shrub in front of my favorite bagel shop.  
 
The oleanders were growing back nicely. However, there were yellow aphids on the young leaves.
 
Years ago, my oleander shrubs had an infestation of yellow aphids like this, and I was anxious to get rid of them. Really, this is our first reaction when we see bugs on our plants – we want them gone.
 
I had several methods at my disposal – insecticidal soap, a strong jet of water or my fingers – all of which, would help get rid of most of the aphids. But, life got in the way, and I didn’t have a chance to get out to treat my shrubs until about ten days later.  
 
Can you guess what I found?  Not a single aphid.  I didn’t have to do a thing, and the aphids were gone, and my shrubs look great.
 
So, what happened to the aphids?
 
When harmful insect pests first appear, it can take a week or two before their natural predators follow. In the case of aphids, lacewing and ladybugs showed up and ate the aphids.  
 
Plants are tougher than we give them credit for and can handle a certain amount of insect pests without any adverse effects.  
 
So, when I come back in a couple of weeks to the same bagel shop, I expect to see no aphids in sight and a healthy oleander shrub.
The lesson here is that you don’t need to freak out when you see aphids as the normal cycle of nature will take care of them. However, you can step in to get rid of them if you see adverse effects on plants such as wilting, smaller blooms, or discoloration.

No matter where you live, you will see the same shrubs being used over and over again in countless landscapes. While the shrubs may be attractive, their overuse throughout neighborhoods creates a boring appearance because they are so common.

 

In California, Nevada, and Arizona, oleanders have held a prominent spot in the landscape for years. Their popularity is due to their lush evergreen foliage, ability to withstand intense heat, and their pretty flowers.

However, their overuse in many areas makes their beauty less impactful and frankly, almost forgettable.

 At a recent conference, this point was put quite succinctly by the head of horticulture for Disneyland who said,

“When things are expected (in the landscape), they become less powerful and impactful”.

His statement sums up what happens when we use the same plants over and over.

In the case of oleanders, there is another problem.

 
 Oleanders are susceptible to a fatal disease called, oleander leaf scorch. This disease has come from California into Arizona where it is popping up in neighborhoods in Phoenix and also Lake Havasu. I have consulted with several cases affecting large, mature oleanders in Arcadia, Biltmore, and Moon Valley areas in Phoenix. 

This bacterial disease is spread by leaf-hopper insects and there is currently no known cure or control available. Infected oleanders slowly decline over 2-3 years before dying. To date, dwarf oleanders have not shown signs of the disease, only the larger forms. But, that could change sometime in the future.

Objectively, there’s a lot to like about oleanders; they thrive in hot, dry climates with minimal fuss, have attractive dark green foliage, and add color to the landscape when in flower. However, their overuse in the landscape makes them less impactful and coupled with their susceptibility to oleander leaf scorch, people want an alternative. 

You can learn more about this disease that affects oleanders here.

Hop Bush: 

 
When asked for another option for the large, tall forms of oleanders, I recommend Hop Bush (Dodonaea viscosa), also known as Hopseed Bush.
 
This native desert shrub has attractive, evergreen foliage and a similar growth habit to oleander. They grow up to 12 feet tall or prune to a shorter height.
 
 
Use Hop Bush in the same ways as oleanders to provide a nice green hedge or privacy screen.
 
Hop bush flower
 
While they don’t have colorful flowers; they have lovely foliage that is only mildly poisonous as opposed to oleanders which are highly toxic.
 
 
Hop bush has a lovely natural shape or prune as a formal hedge.
 
Want to learn more about this oleander alternative? In my latest Houzz article, I share what types of plants look nice next to hop bush, how to care for them and show a purple-leaf form.
 
I hope that you find a spot for this lovely shrub in your landscape.

Have you ever seen hop bush growing in the landscape?  

Gardeners have long known about white flowering plants and the beauty that they bring to the garden.

The color white is seen by many as a bright, clean color that makes surrounding colors ‘pop’ visually.  Others like how white flowers seem to glow in the evening and early morning hours in the landscape.

Thankfully, there are several white flowering plants that do very well in the Southwestern landscape. In Part 1, I showed you four of my favorites, which you can view here.

Today, let’s continue on our white, floral journey…

Disclosure: Some of the links below are affiliate links, meaning, at no additional cost to you, I may earn a commission if you click through and make a purchase.

 

White Evening Primrose (Oenothera caespitosa)
 
The arrival of spring transforms the low-growing green foliage of White Evening Primrose with the appearance of beautiful white flowers. What makes these flowers somewhat unique is that as the flowers fade, they turn pink.
 
White Evening Primrose looks best when used in a landscape with a ‘natural’ theme or among wildflowers.
 
The flowers appear in spring and summer on 10″ high foliage.  Hardy to zone 8 gardens, this small perennial is native to Southwestern deserts.
 
White Globe Mallow (Sphaeralcea ambigua ‘White’)
This is a shrubby perennial that is in my own landscape.  While the most common color of Globe Mallow is orange, it does come in a variety of other colors including red, pink and white – all of which I have.
 
The white form of Globe Mallow shares the same characteristics of the orange one – it thrives in full sun and can even handle hot, reflected sun.  The foliage is gray and looks best when cut back to 1 ft. high and wide after flowering in spring.
 
I pair white Globe Mallow alongside my pink ones for a unique, desert cottage garden look.
 
 
See what I mean about white flowers helping other colors to stand out visually?
 
Hardy to zone 6, Globe Mallow grows to 3 ft. tall and wide.  It does best in full sun and well-drained soil.
 
To learn more about this beautiful desert native, click here.

                                    Blackfoot Daisy (Melampodium leucanthum)

 
Blackfoot Daisy is another perennial that looks great in a natural desert-themed landscape.  This ground cover produces sunny, white daisies in spring and fall in desert climates – it flowers during the summer in cooler locations.
 
Hardy to zone 5, Blackfoot Daisy can handle extreme cold when planted in full sun.  I like to plant it near boulders where it can grow around the base for a nicely designed touch. It grows to 1 ft. high and 24 inches wide.
I have several in my front garden and I love their beauty and low-maintenance. They need very little maintenance other than light pruning with my Felco Hand Pruners in late spring to remove dead growth.
 
Little Leaf Cordia (Cordia parvifolia)
 
This white flowering shrub is not used often enough in the Southwestern landscape in my opinion.  It has beautiful flowers, needs little pruning if given enough room to grow, is extremely drought tolerant and evergreen.
 
Little leaf cordia can grow 4 – 8 ft. tall and up to 10 ft. wide. Unfortunately, some people don’t allow enough room for it to grow and shear it into a ‘ball’.
 
You can go 2 – 3 years or more between prunings. It’s best when left alone to bear its attractive, papery white flowers spring into fall.
 
Hardy to zone 8, little leaf cordia does great in full sun and well-drained soil.
 
‘White Katie’ Ruellia (Ruellia brittoniana ‘White Katie’)
 
During a visit to a nursery some time ago, I noticed a white flowering variety of the more commonplace purple ‘Katie’ ruellia and I immediately decided that I liked the white color better.
 
‘White Katie’ ruellia grows to 8 inches tall and 1 1/2 ft. wide in zone 8 gardens and warmer.  It looks great when planted in groups of 3 or more.  You can plant it alongside the purple variety for fun color contrast.  It does suffer frost damage when temps dip below freezing but recover quickly in spring.  
 
This white flowering perennial does best in morning sun or filtered shade in desert gardens.
 
I hope you have enjoyed these white flowering plants and decide to add them to your garden!  
  

Does it look like fall where you live?

If you live in the West or Southwestern regions of the U.S. your answer is probably “no”.

Fall foliage we enjoyed on a trip to Williamsburg, VA several years ago.
 
Have you ever traveled somewhere else to find colorful fall foliage?
 
What if you could have fall color in your own landscape?
 
Believe it or not, there are several plants that can offer some fall color for those of us who yearn for signs of autumn in the desert garden.
 
I shared 6 of my favorite plants for fall color in an article I wrote for Houzz.
 
Do you have a favorite plant that gives you fall color?
 

The signs that fall is approaching are sometimes so subtle that it is easy to miss them.  But, they are there just the same.


You may notice the lengthening shadows on your way home from work, signaling shorter days.  Or maybe you’ve noticed that you aren’t rushing indoors as quickly as you did earlier this summer.

 
Fall is a time to celebrate the end of hot summer temperatures and what better way to do that than to venture out into the garden again?
 
Before you head out to shop for plants, it’s important to pick the right ones or you may be left with a dead or struggling plant and a thinner wallet. 
Here is my most important piece of advice before you head to the nursery:
 

Research plants before buying.

 
It sounds simple, doesn’t it?  But you would be surprised to learn that most people don’t research plants before they add them to their landscape.  
 
There are three questions you should have the answers to before planting.

online-class-desert-gardening-101

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1. Know how large your plant will grow at maturity.

 
Neglecting to get the answer to this question can have unfortunate results.
 
This homeowner had ficus trees planted in the raised bed around their swimming pool.
 
Now, when you look at this picture, you may be wondering why would anyone plant ficus trees in this area.
 
Newly planted ficus tree
 Well, it goes without saying that new plants are much smaller than they will be once they are planted and have a chance to grow.
 
Mature ficus tree.
 
But, once plants are in the ground and begin growing, that small little plant can increase in size exponentially.  In this case, the ficus looks like it is ready to swallow up this house.
 
Over-planted shrubs
Another example of not researching the mature size of plants can be seen in many landscapes throughout the Southwest.  
 
In a nutshell, the small 1 foot tall and wide shrub in the nursery can grow more than 10X its original size.
 

2. Know what exposure the plant does best in.

 
Putting a plant that needs full sun in a shady spot will result in a leggy plant with few leaves and almost no flowers.
 
What a plant that does best in filtered shade looks like when planted in full sun.
 
Conversely, if you place a plant that does best in the filtered shade in an area that gets full, afternoon sun – it will suffer.
 
You will save yourself a lot of time, money and frustration by simply placing plants in the exposure they like.
 

3. What type of maintenance will your plant require?

 
Fuss-free Eremophila ‘Summertime Blue’
 
Some plants need frequent pruning, fertilizing and protection from pests.
 
Others are what I like to call ‘fuss-free’ and need little else besides water.
 
The amount of maintenance a plant needs is largely dependent on whether or not it is native or adapted to your client.
 
 
For example in the Phoenix area where I live, queen palms are very popular.  The problem is, is that they are not particularly well-adapted to our desert climate.
 
In fact, it is rare to see a healthy queen palm growing in the greater Phoenix area.  Frequent applications of palm fertilizer are required to get them to look okay and even then, they will never look as good as those growing in Florida or California.
 
I don’t like to fuss over plants except for a couple of rose bushes in my garden, so I am a strong proponent of using native or adapted plants that need little pruning, no fertilizer and aren’t bothered by insect pests.
 
Now we know three important questions to get answered before selecting plants for your garden.
 
So, where can you go for the answers to these questions?
 
There are a few different places you can go to find out these as well as other questions.
 
Master gardeners are an invaluable resource and their job is to help people learn how to grow plants successfully. You can call them, email your questions or stop by and talk to them in person.
 
Take some time to visit your local botanical garden. Write down which plants you like, or snap a photo of them with your phone. Note how large they are and what type of exposure they are growing in.
 

I have a weakness (well, one of many) to confess to you today….

I absolutely love salt.  

In fact, I have a theory that the reason that so many people love french fries is not the potatoes or the fat it is fried in. No, it is the salt that you put on them afterwards. I mean, can you imagine eating an unsalted french fry? 

In preparation for this blog post, I went through my kitchen and pulled out all of my salt & pepper shakers.

 
It’s kind of embarrassing isn’t it?  I have so many.
 
But in my defense, I must admit that I collect different types of pottery and need salt and pepper shakers for each set.  
My husband made me my wooden salt cellar, which I keep near the stove when I cook.
 
Now, I do not use as much salt as I used to. In fact, I am trying to be better about it.  When I visited the doctor earlier this week for my physical, I still had low blood pressure, much to my relief.
 
Well, we all know that too much salt is bad for you and can lead to health problems such as high blood pressure. But did you know that too much salt is not good for your plants as well?
 
Plants don’t get ‘high blood  pressure’ with too much salt, but they do have another problem that shows up.
They get brown tips on their leaves, which we call ‘salt burn’.
 
white-crusty-salt-build-up-plants

Here is another way that you can tell plants are getting too much salt. Shallow watering causes the water in the soil to evaporate quickly, leaving behind the salts. The salts look like a white crust on the soil around your plants.

At this point you may be wondering how plants get too much salt?  

Well, both soil and water have naturally occurring salts in them. This is especially true in the Desert Southwest where our water is somewhat salty and our soils can suffer from salt build-up due to high evaporation.
 
So what do you do if you have indoor or outdoor plants that have brown tips?
The solution is very easy.
 
Water deeply.
 
That’s it!
 
 
Here is a shrub that has signs of salt build-up. I encountered with one of my clients during a landscape consultation – he had other shrubs that looked similar.
 
I will tell you what I told him:
 
If your outdoor plants look like this, first water the affected plant with your hose on a slow trickle for at least 2 – 3 hours.  This helps to ‘leach’ or flush the salts away from the roots.
Thereafter, adjust your irrigation schedule so that your shrubs are watered to an approximate depth of 18 inches deep each time. Sadly, most people water too often, too shallow and not long enough.  
 
For example, I water my shrubs and perennials every 5 – 7 days in the summer. This takes approximately 2 hours for my plants to be watered to a depth of 2 ft. Of course the time it takes to water that deeply is different for each landscape and is dependent on a variety of factors including soil type and water pressure.
If your houseplant has brown tips (salt burn), then simply flush the salts out by deeply watering.  You can do this by putting your plant in the sink or bathtub and let water slowly trickle on your plant for 1 – 2 hours.
I cover landscape irrigation in depth with my students in my online course, Desert Gardening 101, but for those of you looking for advice right now here’s what I recommend. Search online for watering guidelines on your city’s website – most have schedules including recommended depths.
So in closing I’ll leave you with these two tips:
Be sure to limit your salt intake AND water your plants deeply to prevent salt burn.
Do you have plants that need extra water this summer? 
Many of us have a few plants that aren’t connected to an irrigation system. Some people don’t have an irrigation system and use a hose to water plants, which is time-consuming and inefficient.
 
While you can certainly haul out your hose and water each of your thirsty plants, it is not the best way. The main problem is the hose puts out water quickly and the soil can’t absorb it fast enough. As a result, much of the water runs off and doesn’t benefit the plant as much as it should.
So, if the time-consuming task of watering plants by hand isn’t your cup of tea, I’m here for you. You can make life easier by creating your own portable drip irrigation system with a recycled milk jug
This solution is very easy and will have you digging through your recycle bin collecting your used milk jugs.

To get started, you will need an empty plastic milk jug and a nail.

1. Heat the nail using a lighter or stove burner. Then use the nail to pierce 3 – 4 small holes in the bottom of the milk jug.
2. Fill the milk jug up with water, put the cap on and carry it upside down to the plant. Turn it right side up and set it down to the plant that needs irrigation. *You can also set the empty milk jug(s) next to your plants, bring the hose to them and fill with water that way.
3. Slightly loosen the cap, which will allow the water to drip out of the holes at the bottom – this allows the water to penetrate the soil slowly, instead of running off.

Once the water has drained out of the bottom of the jug, pick up your milk jug and move it to the next plant. After you are done, bring the empty jugs inside and store until the next time you need them.

If you live in a windy area and worry the milk jug will blow away, weigh them down with an inch of small rocks in the bottom of the jug – the rocks won’t interfere with the water dripping out.
I usually recommend this method of irrigating cacti monthly in summer.
This portable drip irrigation system is a great aid for those who live in areas that are suffering from drought or where an irrigation system may not exist.
**A semi-permanent variation of this method is to create holes along the sides instead of on the bottom. Then bury the entire jug next to the plant, leaving just the top exposed. To water plants, remove the milk cap and fill with water and replace the cap.
I hope you find this DIY garden project helpful. Please feel free to share it with your friends by clicking the “Share” button below. 

I have a confession to make.  

I don’t have any containers filled with flowering annuals. Shocking isn’t it?

There are a few reasons for this, the most important one is that I prefer using relatively fuss-free plants that look great all year in my pots.  

I don’t have much patience for high-maintenance containers. In particular, ones with flowering annuals that need frequent irrigation. Not to mention deadheading of spent flowers and having to change them out seasonally. But, I do love the way they look.

container-red-geraniums

Red Geraniums and White Bacopa

My inclination to avoid flowering annuals in my own garden has to do with my past and no, it’s nothing scandalous.

It does have to do with my work in the past. For five years, I was in charge of 45 pots. Each container was always be filled with colorful flowers.

Believe me, keeping all of those pots looking beautiful was a lot of work! Countless trips to the nursery, fertilizing, watering and replacing them twice a year got tiresome. Not to mention that I broke my foot when I tripping on a curb, while loading flats of flowers. 

So, it may not come as a surprise that I prefer using succulents in my pots.

Victoria Agave ‘Compacta’
 
Much of my inspiration for using succulents in containers come from those at the Desert Botanical Garden as shown in the photo above and below.
Agaves are some of my favorite succulent plants and the smaller species do very well in containers.

In an article I wrote for Houzz, I list my ten favorite small agaves for Houzz that are suitable for growing in pots.

I hope you enjoy it and find one that is perfect for you!
 
 

“How much water do my plants need?”

I am often asked this question by desert dwellers and my answer is always, “That depends.”

desert-landscape

There are several variables that determine how much water plants need, along with the frequency of watering.

Variables include:

  • Type of soil (clay, sand, combination)
  • What kind of plant (native plants, higher water use flowering shrubs and ground covers, succulents, etc.)
  • Recommended depth of water
  • Desert region (low-desert, mid-altitude, high desert)
  • Efficiency of irrigation system
  • Water pressure (can vary between neighborhoods)
As you can see, there is no universal watering guideline in regards to how long to water or how often.

Let’s look into the variables a little more closely to help you determine what yours are:

 

SoilClay soils hold onto water longer than sandy soil. They take longer for water to permeate to the recommended depth. The result? Clay soils need irrigation less often than sandy ones but need to be watered for a longer length of time. Phoenix area soil tends to have more clay in them while those in the Palm Springs area are sandy.

Plants – Native or desert-adapted plants need less frequent irrigation versus those that come from tropical climates. Cacti and other succulents do well with infrequent irrigation.

Water Depth – Trees need to be watered deeply while ground covers and succulents do fine at a more shallow depth – shrubs fall in between the two.

Desert Region – Where you live in the desert matters when it comes to water and your plants. The differences include rainfall amounts, when the rain falls, high and low temps, and more. Residents of low-desert cities like Palm Springs and Phoenix need to add water to their plants more often than those who live in higher elevation regions such as Tucson.

Irrigation System – The older your irrigation system, the less efficient it is. This is due to mineral build-up within the system, which affects the amount of water that comes out. Also, old drip irrigation systems tend to accumulate leaks. The average lifespan for a drip irrigation system is 10-15 years. 

Despite these differences, what is a shared characteristic is that the vast majority of desert residents water too often and not deeply enough. This is usually due to lack of knowledge and thinking the ‘more is better,’ especially in the desert.
Landscapers are generally not a reliable source when it comes to scheduling irrigation – most recommend irrigating far too often.
 
So what is a desert dweller to do?
Thankfully, there is very useful information available for homeowners to help them figure out when and how much water their landscape needs.
 
Major metropolitan areas throughout the Southwest have excellent watering guidelines available for residents. The guidelines include the regional variables we have discussed so far.
Here are helpful links based on major desert cities (click the link for the city closest to you):
Watering guidelines are just that – guidelines. Circumstances may mean that you need to water more or less often, but these guides are a useful baseline to work from.
*One final note – before you implement a new irrigation schedule, it’s important to gradually wean your plants to the new one over several weeks. The reason for this is that it allows plants to become accustomed to the new schedule.

Yes, it does take a little work to figure out how much and often to water your plants, but these guides are incredibly helpful and will guide you along the way.