Don't let a sudden heat wave ruin your succulents! Case in point: Much of April here in Southern CA was rainy with highs in the 50s. Now, coming into the last week of April, the forecast is for temps in the 90s. (What, pray tell, happened to the 60s, 70s and 80s?)
This is bad news for our gardens. Tender new plant growth resulting from rainstorms needs time to toughen. When a heat wave follows cool weather, succulents exposed to hot sun may burn. There's no fixing the beige or brown patches that result from sunburn. One of the best things about succulents is also the worst: they keep their leaves for a long time. Damage may be visible for quite a while.
Two ways to protect your succulents
- Move them. Of course this is only possible if they're in pots. But don't forget to do it! Move plants out of harsh midday sun and provide more shady hours daily.
- Cover them. This is advisable for delicate, thin-leaved, in-ground succulents---in particular those you prize---and anything newly planted. Protect echeverias, kalanchoes, dainty sedums, sansevierias, sempervivums, caudiciforms, and chubby and Medusa euphorbias (among others). Use floating row cover ideally; or shade cloth, old sheets or screens. Remove as temps return to normal.
How to Water Your Succulents in Summer
- Water early in the morning or late in the day. Note to desert gardeners: Watering in midday heat can literally cook roots. (Eek!) HOWEVER, aeoniums, dudleyas and other succulents that have closed their rosettes should be watered minimally or not at all, lest dormant roots rot. The plants will revive when the rains return. (They may not make it until then, though, if in full sun. So, shade them.)
- If the ground is concrete-hard, leave a hose dripping overnight to create an underground cone of moist soil.
- Trees and shrubs want water where their canopies would naturally direct rainfall: around the perimeter of the plant.
- Add gravel topdressing around succulents (or use organic mulch for woody plants) to help hold moisture in the soil.
- When hose-watering, take the opportunity to blast pests, fallen leaves and dirt out of leaf axils and the centers of rosettes.
- Use a hose-end sprayer—ideally one with multiple settings—to direct water where you want it.
- A hose lying in summer sun may contain scalding water. You already know this, but your house-sitter may not, so be sure to mention it. If you have a hose-full of hot water, aim a fine spray skyward. Droplets will cool by the time they hit leaves.
No need to worry about...
Tougher succulents like ice plants, cacti, crassulas, elephant's food, beaucarneas, senecios, yuccas, and large aloes and agaves will probably be OK. But every plant is different. Variegates, for example, tend to scorch more easily due to less protective pigment.
Watch the video
Be sure to watch my 10-min. video: Protect Your Succulents from High Heat and Sun. On an 89-degree day I take you on a tour of my garden in the foothills NE of San Diego. You'll see what's in bloom, lookin' good (or sadly dreadful), and watch as I check the health of succulents small and large.
Related Info on this site
Don’t let summer sun and heat harm your succulents! Heat generally isn’t a concern. Although some succulents (like sempervivums) tend not to thrive in temps above 80 or 90 degrees F, the majority are fine. It’s heat plus sun that’s the concern.