Tag Archive for: native plants

What do your plants look like in the middle of summer?  Do they thrive despite the hot temperatures?  

Or do they look more like this?

Heatproof Gardening tips

Throw in a heatwave, and your lovely, attractive plants may be suddenly struggling to survive.

Whether you live in the desert Southwest or more temperate climates, this can happen to you if your garden is not prepared for the heat of summer.

So, how do you know if your plants are handling the summer heat?  

Take a walk through your garden during the hottest part of the day and look for signs of wilting leaves as well as yellow or browning leaves.  All of these can indicate heat stress.

The good news is that you can heatproof your landscape and enjoy a garden filled with attractive plants that thrive despite the hot temperatures that summer dishes out.

Here are 5 tips to help you heatproof your garden:

#1. Use native or plants adapted to your climate.

Heatproof Gardening tips

This is perhaps the most important tip for having an attractive, low-maintenance landscape filled with beauty that thrives throughout the entire year.

Native (or adapted) plants have unique characteristics that help them to handle the local climate, including the heat of summer AND the cold of winter.

All too often, we find ourselves with landscapes filled with plants (often with large leaves) that struggle to survive the hot, summer months.  This results in unattractive plants that we work hard to help sustain them until cooler temperatures arrive.  Usually, these plants are best meant to grow in climates with less extreme heat.

Langman's Sage (Leucophyllum langmaniae)

Langman’s Sage (Leucophyllum langmaniae)

Let’s look at an example of an adaptation that this Langman’s sage has that enables it to handle full sun and 110+ temperatures without undue stress.

Notice that the flowers have small hairs.  So do the leaves, giving them a slightly grayish cast.  These tiny hairs help to reflect the sun’s rays, which lowers the temperature of the leaves and flowers.

Mexican Honeysuckle (Justicia spicigera) and Shrubby Germander 'Azurea' (Teucrium fruticans 'Azurea')

Mexican Honeysuckle (Justicia spicigera) and Shrubby Germander ‘Azurea’ (Teucrium fruticans ‘Azurea’)

Another way that plants have to handle the heat is by having small leaves, which limits the amount of water lost, which helps them to deal with hot, dry temperatures.

Here in the desert Southwest, there are many native plants that are used as well as plants from Australia and other arid regions, which have similar climates.

#2. Provide shade

Heatproof Gardening tips

Adding shade to the garden can provide relief from the hot sun as well as cooling air temperatures.  The shade benefits plants and can provide cooling to the house as well.

*It is important to note that it can be hard to grow many plants in dense shade – especially flowering ones.  However, using trees that provide filtered shade provide just enough shade while allowing enough sun through for plants.

#3 Water deeply and infrequently

Heatproof Gardening tips

Plants need water to survive, and not surprisingly, they need the most in the summer.  However, we often water them too often and shallowly for it to do much good.

Shallow watering keeps roots close to the surface of the soil, where the soil temperatures are hot, and the water dries up quickly.

Deep watering is the proper method for irrigating plants because encourages deep root growth where the soil is cooler and stays moister for longer.  As a result, you do not need to water as often.

“Plants that are watered deeply and infrequently are better able to withstand the heat.”

Shrubs should be watered to a depth of 2 feet and perennials and groundcovers to 18 inches.  You can determine how deeply you are watering by inserting a piece of rebar down into the soil (right after you have finished watering) to see how long you need to irrigate.  On average, 2 hours is the length of time to irrigate to the desired depth.  

In my online class, Desert Gardening 101, I teach my students that watering deeply is as important as the time of day that you water. The best time to water is early in the morning.  Watering plants in the afternoon is not as useful since plants allocate their resources at that time toward surviving the stresses of the heat and so they do not take up water as efficiently.  

#4 Mulch around your plants

Heatproof Gardening tips

Not surprisingly, mulch has a variety of benefits and not just in regards to heat proofing your garden.

Mulch serves to help cool soil temperatures in summer while helping to conserve moisture – all important in helping plants thrive despite hot temperatures.

A bonus is that they also help to prevent weeds from taking root.

Heatproof Gardening tips

Let’s take a minute to rethink our definition of what makes an excellent mulch.  

While shredded bark and wood chips may come to mind, did you know that fallen leaves, pine needles, and even fallen flowers can also serve as a mulch?  That is how nature does it.

So, the next time you are tempted to whip out your leaf blower, how about directing it toward the base of your plants where the leaves and flowers can serve as a mulch?

They will also help to improve the soil around your plants as they decay.

#5 Ditch flowers in favor of succulents in containers

Gardening tips

Tip for Heatproof Garden

While growing pretty flowers in containers is relatively simple in fall, winter and spring-summer can be another matter entirely.  Often, it can be hard to grow flowering annuals in pots throughout the hot summer.

The reason for this is that the soil around the roots of container plants is hotter than if grown in the ground.

This is especially true for the outer 6 inches of soil which heats up in response to air temperatures and the hot container.  As a result, annuals can wilt and struggle to produce flowers in summer.

Succulents are a great way to enjoy attractive container plantings throughout the year, not just in summer.  Their ability to store water is what makes them an excellent choice for containers.

Gardening tips

Tip for Heatproof Garden

If you want to grow something else besides succulents, how about trying heat-tolerant shrubs? Bougainvillea does great in pots as does lantana.

Gardening tips

Tip for Heatproof Garden

Another tip for containers is to leave them empty in the summer months and wait until fall to plant them.  

When thinking in terms of growing plants in containers in hot climates, bigger is better – at least 2 feet wide at the top.  The larger the pot, the more soil and therefore, more insulation for the roots from the hot outer zone.

**So what can you do if you do have plants that are struggling in the heat – particularly during a heatwave?  

Other than replacing them, you can provide them with temporary shade such as a patio chair strategically placed so that it protects it against the afternoon sun. A light spraying of water over the plant and surrounding area in the evening can help reduce the temperature – don’t do this when the sun is out, or you may burn the foliage.

How to Help Your Plants Survive a Heatwave

Fall planting

Fall planting

It’s hard to believe that we have made it through another summer.    

Oh, I realize that we have a few more weeks of 100+ degree weather, but whenever there is month that ends with the letters “ber” it just feels cooler to me.  

I am gearing up for my favorite season in the garden.  In my last post, I talked about the reasons why fall is the best time to add new plants to the Southwest landscape.    

Today, I’d like to share with you three tips to help you make the most of your fall planting.

This planting hole is too small

Photo: This planting hole is too small.

It all comes down to the hole.  It’s hard to believe that often what determines a plant’s initial success is the size of the hole it is planted in.  

If you are digging holes like the one above – then you may be in trouble.  That hole is too narrow.

Fall Planting

The ideal hole should be 3X as wide as the root ball.    

Why?  

Well, most of a plant’s roots grow outward into the soil.  When they are placed in a hole like the one above, the recently loosened soil makes it much easier for roots to grow into, which helps the plant to establish much sooner.  

*It’s important to note that the depth of the hole should be the same depth as the root ball or even a few inches shallower.  This helps prevent problems from the dirt settling, which can leave your new plant sitting rather low in the soil where problems with becoming waterlogged can happen.

Fall Planting

The big question – whether to add soil amendments or not?

When you go to your local nursery to buy new plants, you may be encouraged to buy soil amendments such as compost, potting soil or even manure.

The question is, do you really need it?  Often you don’t.    

I have planted thousands of plants throughout my career as a horticulturist and most of them without adding anything to the soil.  The plants were healthy and did very well without any extra additions to the soil.  

Here a few guidelines to follow to help you decide whether or not to add any amendments to the soil before planting.  

– If your soil is well-drained AND your new plants are native to any of the desert regions of the United States, than the answer is “no”.    

Native plants are adapted to growing in the nutrient poor soils of the desert and do best when nothing is added to the soil.  In fact, if the soil is too fertile – you’ll often see green growth, but flowering will be decreased.

Valentine (Eremophila maculata), Feathery Cassia (Senna artemisoides) and Purple Trailing Lantana (Lantana montevidensis) planted without needing any soil amendments

Photo: Valentine (Eremophila maculata), Feathery Cassia (Senna artemisoides) and Purple Trailing Lantana (Lantana montevidensis) planted without needing any soil amendments.

The same can be said of some non-native plants – particularly those from Australia such as Eremophila and Senna species.  

So, are some times when adding soil amendments is a good idea?  

Absolutely!  

– If you have heavy clay soil or very sandy soils, than adding compost to the planting hole can help.  Mixing compost in with clay soils help them to drain better.  This is important because most plants that grow in the Southwest do best in well-drained soil.  

Conversely, sandy soils have a hard time holding onto enough water, so compost helps those soils to hold onto more water.   Add 1 part compost to 1 part native soil and mix together before planting.

require fertile soil to grow their best.

– Amend the soil when planting non-native plants that do not originate from arid climates.  

Plants like day lilies, iris, roses, etc. require fertile soil to grow their best.  Amending the soil with compost, manure and other amendments will improve the soil texture, add small levels of nutrients and add beneficial microorganisms which will benefit your plants.    

Plants such as these will need regular applications of fertilizer to do their best.  

Personally, I like to grow what I like to call ‘fuss-free’ plants where I don’t have to add fertilizer with the exception of my roses.  

Fall Planting

Skip the fertilizer for newly planted plants.  This tip is NOT always popular with some nurseries who often encourage the application of fertilizer at the time of planting.  

So, let’s talk about when to add fertilizer.  

– Most native plants will not need fertilizer ever.  In fact, many can make their own fertilizer.  

– For plants that do need fertilizer such as hibiscus,  iris, roses, etc. – wait until you see new growth occurring before adding fertilizer.  

The reason for this is that when you first add a new plant, it needs to concentrate on growing new roots in order to support future top growth (stems, branches and leaves).  If you add fertilizer at the time of planting, you are forcing the plant to focus on the top growth before it has the roots to support it.

So, a general rule is to wait until you see new top growth before adding fertilizer.  

– The rule for fruit trees is slightly different.  It is recommended to wait until 1 year after planting before fertilizing.  

Again, you may hear differently from your nursery who in addition to wanting you to be happy with your purchase, also has their bottom line (profits) in mind.  

I am not including all nurseries or nursery professionals into this one group.  However, I have visited nurseries where customers are told that they need to fertilize all their plants.  Many of my clients are thrilled when I tell them to throw out their fertilizer because their native plants don’t need it.  

*I remember a story from one of my horticulture professors who talked about standing in line behind a customer at the store with a cart filled with native, desert plants and another cart with ‘special’ fertilizers that they were encouraged to buy.

My professor loudly commented to her husband, standing next to her, that “Numerous studies have shown that fertilizer is a waste of money when used for native plants.”    

So, are you ready to add some new plants to your landscape?   Before you head out to the nursery, I invite you to come back for my next post, when I’ll share with you some tips on how to select healthy plants AND I will reveal to you what my favorite plant nursery is!  

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I apologize for the relative lack of recent posts.  Life has been very busy with the kids back in school, increased landscape consults and getting ready to go visit my daughter, Rachele, who is expecting.  We will find in a few days whether we will be welcoming a boy or girl!  

I have two biological children – both girls and my oldest daughter, Brittney, has a daughter.  So, we will see if Rachele will break the pink trend in our family.  

My son Kai (who is adopted from China) and has four sisters and a niece is really hoping for a boy 😉