What Succulents Will Work in the Hot Desert?

Q. I love the California look of lots of succulents planted in the yard and in pots on the patio. We moved into our new home late last summer and I placed some potted succulents around the pool area. Most of them burned and died because of the intense sun. What succulents survive in direct sun here in Las Vegas? I’d like to plant some in the ground as well as grow some in pots. 

A. This is a two-part question; what is a succulent and how to change a harsh desert climate into one that’s favorable to grow succulents 12 months of the year.

            The category of succulents is huge. Succulents have some plant part which can store water when water is not available. Cacti are a type of succulent. But there are succulents which are not cacti. The succulents you like are probably the “fleshy” succulents. These types of succulents grow best in dry climates that are cooler than our Mojave Desert climate. Low humidity is not a problem. It’s the intense sunlight, high temperatures and poor soils that create problems for them. Mediterranean climates, warm or even hot in the summer while wet in the winter, typically favor fleshy succulents. Coastal southern California is a warm Mediterranean climate but the interior valleys are part of the Mojave Desert and, just like ours, fleshy succulents won’t do well there.

            Your first selection criterion is the winter low temperature. If it does not survive in winter freezes then replant in the spring every time there is a winter freeze. There will be winters it doesn’t freeze and other winters it might freeze two or three years in a row. There are areas in landscape that are warmer than others called microclimates. There are also microclimates in communities within the valley that are warmer than others.

It is good to remember because as you have found out ornamental succulents will struggle to perform in our desert climate during our intense heat and sunlight. Even some cacti that come from milder climates struggle in the Mojave Desert. A second point to remember, all plants perform better in the heat and dryness of a desert climate if they are healthy. This means that even cacti and other succulents which are not cacti will be healthier if the soil is amended with compost before they are planted. I know it does not sound logical but I have found that in many of our desert soils in the Mojave Desert there just is not enough organics in the soil to promote strong health and good growth of cacti and other ornamental succulents

            The exposure to direct sunlight can be a problem for most succulents in our Mojave desert climate. This is not the case in gentler, more Mediterranean climates like coastal Southern California. We can still grow in the Mojave Desert many of the same plants provided they withstand our winter freezing temperatures and are planted in different locations than you would plant in coastal Southern California.

            Some favorite succulents to plant include Aloe Vera, Hearts and Flowers (Aptenia), Hen and Chicks and others. What most people do not understand is they are missing some very important succulents in the groups that we think of mostly as cacti: agave and yucca. These two groups of plants are full of species that are cacti and others that are true succulents.

Remember the following when selecting succulents and where to plant them:

1.         They may freeze. Sometimes we have freezing temperatures and other times we may not. If the succulents you pick are tender to freezing temperatures you will lose them some years. Expect that and buy more and replant in late spring.

2.         Provide protection from late afternoon intense desert sunlight. Some succulents require more light than others. If they produce flowers that you like then they need more sunlight. Those succulents that don't produce any important flowers can be planted on the east side in partial shade. Most succulents can handle early morning sunlight until about 10 AM and they should be in partial sun the rest of the morning and in the shadows late afternoon.

3.         Amend the soil with compost at planting time. Good drainage is important to these plants so the soil must drain water. Adding compost as a soil amendment improves drainage (soil structure) and provides plant nutrients for growth. Succulents will be happier planted in amended soils.

4.         Water succulents in the morning. Most small succulents need irrigations every day during the heat of the summer. Water them with a valve used for irrigating lawns, annual flowers or vegetable beds. Larger succulents like many of the yucca and agave can be watered more like small to medium sized shrubs. Size makes a difference!