Don’t allow the hot, harsh sun hurt your succulents! Unlike frost (temperatures of 32 degrees Fahrenheit or lower), heat normally poses no threat to succulents. The majority of plants can tolerate temperatures higher than you’re comfortable with, as shown by greenhouse temperatures that rise into the triple digits on hot days, despite the fact that some don’t seem to thrive in temperatures above 80 or 90 degrees F. Succulents, though, can succumb to heat and sunlight. All smooth-leaved succulents, excluding desert cacti and agaves, require sun protection in the summer, especially when the temperature rises beyond 80 degrees.
If you live in an arid climate ~
- Identify the sun’s position relative to your property. In North America, plants growing on the north side of your house will receive the least solar exposure while those growing on the south will receive the most. My garden, which faces east, receives early sunlight and midday shade. West-facing gardens receive early shade and afternoon sun.
- When temperatures are at their highest in the middle of the day, “bright shade” (no direct sun but not deep shade) is great for non-desert succulents. For low-light succulents like haworthias, bright shade is needed. Visit our website’s Shade Succulents page to learn more. View my video about Shade Succulents.
Above: Although robust, the echeverias on the left in the brilliant shade have lost their color. The borders of those exposed to more sun are red, but they are smaller due to some stress.
- Keep track of where each new plant you purchase was situated in the nursery. Was it in the open or covered by a tarp? It will need to be “hardened off” (shaded, especially in the afternoon) until it acclimates, even if it is a “full sun” succulent like an agave. This kind of exposure is like tanning: Start with 30 minutes of sun, then gradually increase it by about an hour per day.
- Aloes and crassulas need at least a half-worth day’s of sun to turn red and orange, but not so much that the tips of the leaves shrivel or burn. (Read “How to Stress Succulents and Why You Should. “).
Above: Dryness and heat stress this jade (Crassula ovata). To maintain its life, the plant is gently draining its leaves. However, leaves will be plump and greener after irrigation or rain (which could take months).
- Cover exposed, horizontal stems of trailing succulents (aloes, senecios, othonna, and the like) with dry leaves or mulch to prevent burnt stems from impairing the ability of the plants to transfer moisture from roots to leaves.
- Use floating row covers (preferably), shade cloth, old sheets, or temporary shade structures to protect newly installed plants and in-ground succulents prone to sunburn. I employ rusty window screens. In an emergency, place upright leafy tree trimmings next to a plant you wish to preserve, on the side that receives the most sunlight. Or, in keeping with the sun’s movement throughout the day, use outside furniture.
Above: Aloe brevifolia, a stunning but stressed plant, has closed its rosettes and changed color from blue to pink.
- Learn how plants defend themselves. When the sun becomes unpleasant, succulents can’t flee to the shade, so some species create their own. Succulents with rosettes, such dudleyas, aeoniums, and some types of aloe, close their rosettes to save their critical cores. Lower leaves that become dry but don’t drop off serve a service by protecting flimsy stems from the sun in the summer and the cold in the winter.
- Where shade will be needed during the long, hot summer afternoons, plant trees and plants. (The Companion Plants chapter in Designing with Succulents, 2nd ed., has information on low-water cultivars suitable for succulent gardens.)
What sunburn looks like
The floppy leaves of this agave stretch (and weaken) the cells in those areas that are most exposed to sunlight.
Succulents with white, beige, or black patches have been sunburned, which causes irreparable cell damage comparable to frost. The plant is alright, but scars will endure just as long as the leaf.
These aeoniums generally have sunburn on the underside of their lowest leaves, which they will shed in a few months anyhow. Very effective, wouldn’t you say?
Several months later, the same aeoniums. Only a few scorched leaves are still visible.
It is preferable if the damaged parts are on the outer leaves because fresh growth from the rosette’s center will eventually cover up burnt spots. In any event, lower leaves naturally wither and fall off, damage or not. Recovery from a sunburn could take several months to a year, depending on the succulent and the time of year.
Related Info:
Summertime Succulent Watering. Okay, everyone is aware that succulents require little water. They aren’t “no-water plants,” though. Even though they might make it through the summer without irrigation… [Read more…]
A heat wave shouldn’t ruin your succulents. Succulents that are exposed to the scorching sun may burn when a heat wave follows cool weather. The beige or brown patches that develop as a result of sunburn cannot be removed. [Read more…]
Succulent Stress Management (and Why You Should). Some succulents exhibit beautiful reds and yellows when exposed to lots of sunlight, but how much “stress” the plants need depends on… [Read more…]
Do succulents prefer intense sunlight?
On the east side of my home, where my succulent collection is located, it receives direct sunlight from dawn till around 1:00 in the afternoon. There is a lot of sunlight here!
I’ve discovered that in order to keep the roots cold and the foliage lush, I need to water my plants every other day when the temperature is above 90.
The succulent leaves still get heated despite this constant watering, and I’ve had some, but rather severely. It can be unpleasant when the bright light and hot temperatures combine.
Most succulents will tolerate full sun for the majority of the day if you progressively expose them to it (raising an hour or so every few days).
To shield them from the direct sun, I recently put some shade fabric. Even though it’s still well above 90 degrees outside, the space around the succulents is significantly cooler thanks to the shade cloth.
Additionally, without direct sunlight, the plants’ leaves don’t get as hot and are less prone to burn or exhibit signs of excessive heat.
Haworthias, for example, prefer bright indirect sunlight all day long. On the other hand, the majority of cacti can withstand full sun during the day without any shade. This is why it’s crucial to be aware of the varieties of succulents you own.
The phenomenon known as “blushing,” which occurs when some succulents are exposed to bright sunshine, causes the leaves to occasionally turn a deep red, as with this Aloe ‘Crosby’s Prolific’.
Simply placing your succulents in a location that receives bright shade for the majority of the day is an excellent alternative. They should ideally be in a spot that receives a few hours of early sun but is otherwise shaded for the majority of the day.
Direct sunlight during this time can be an issue because afternoon temperatures are typically higher. On the other hand, morning sun is cooler and less prone to result in sunburn.
For many succulents, extreme heat can be exceedingly difficult. Succulents are often thought of as desert plants, however not all of them thrive in a very hot desert environment.
For more advice on how to keep succulents looking fantastic during a heat wave, see the video below:
The Effects of Temperature on Succulents and Cacti
Succulents and cacti prefer to reside in the “sweet spot” of temperature, just as is the case with sunlight exposure. These hardy plants can suffer irreparable harm from either extreme of the temperature range, so it’s important to monitor their health and adjust the environment as necessary.
Succulents and cacti thrive most effectively in temperatures between 40 and 80 °F. Outside of this range, little temperature swings are tolerated, but swings of five or more can result in permanent harm. Even more intriguing is the fact that temperatures that are on the edge of the bearable range (about 40°F or 80°F) can operate as “stressors,” positively affecting the plant and encouraging the expression of more vivid hues.
Succulents and cacti should ideally be kept above freezing during the winter to prevent frost damage. While more tropical types like euphorbia and lithops demand minimum temperatures of 50 to 60 degrees Fahrenheit, other cultivars are actually frost hardy and prefer cooler overnight temperatures of 30 to 40 degrees. Searching for “ideal temperature for insert plant name here” on Google is currently the quickest approach to find out what temps are optimal for your plants. Each plant product page will eventually feature our own documentation.
Extreme Cold and Extreme Hot
Succulents and cactus can, you guessed it, freeze when exposed to freezing or below-zero weather! The water that has frozen inside the plant’s cells expands as it thaws, killing the cells by rupturing them. When the plant finally thaws out, the damaged regions will start to decay or scar permanently—a symptom that could take a few days to manifest. To stop the rot from spreading, the best course of action in this circumstance is to remove the afflicted region with a clean razor blade.
It is preferable to relocate your collection under a patio cover or inside of your home while the freezing conditions last in order to prevent damage from frost and freezing temperatures temporarily. A “frost blanket,” which is just a thin piece of fabric designed to protect plants from cold, can also be used to cover your plants. Plants should be taken indoors for the winter or placed in a sunroom or greenhouse with plenty of natural light in regions of the country where cold temperatures last for months at a time (essentially everywhere else save California).
However, heated temperatures can also do harm if they are not controlled, so they are not the only bad guys in this tale. A variety of things can happen to your plants when it becomes too hot (90 degrees Fahrenheit and above), especially when combined with full sun exposure. For example, leaves may shrivel and/or burn, water inside plant cells may steam and explode, and root systems may become fried.
Because soil is not a very good conductor of heat or cold, succulents planted in the ground with developed root systems can withstand high heat and cold more better than those planted in containers. On the other hand, containers easily conduct heat and cold, focusing such extremes on the roots of the plants.
There are always exceptions to the norm, just like there are in everything else in life. Succulents can withstand temperatures well below freezing and temps as high as 100 degrees. Drive about and observe what sorts of succulents your neighbors are successfully cultivating to find out what varieties work best in your specific climate.
Moisture and Extreme Temperatures = Bad News
Extreme heat and dampness are among the most troublesome environmental conditions. You should never put your plants in a situation where they are both hot and damp or cold and wet. Whether in the ground or in containers, plants that are grown in dry soil perform far better than those that are not. The water in the soil might start to steam in exceptionally hot weather, thus “cooking” your plants. Water can obviously freeze in freezing or subfreezing temperatures, harming the root system and producing rot. If you absolutely must water your plants when extremely high temperatures are predicted, try to do so as early as possible, ideally before 7 a.m.
The TLDR (too long, didn’t read) Summary
Average temperatures are much preferable to harsh ones for succulents. Frost damage can occur in cold conditions, whereas scorching and atrophy can occur in hot temperatures. Paying attention to what your plants are saying is the simplest method to make sure they are content. Bring them indoors or wrap them in a frost blanket if they are suffering from frost damage. Move them to a sheltered spot or cover them with shade cloth if they are scorching or wilting.
In hot weather, how frequently should I water my succulents?
Summer is coming up quickly! Additionally, proper watering is crucial for happy, healthy succulents as temps climb.
There is a widespread misperception that succulents require little or no water. Given that such fat leaves store a variety of reserves for the plants, there is some validity to the statement “require very little.” However, because of their reserves, they require less irrigation overall than other plants. The truth is that succulents like water, and they prefer to be deeply irrigated, once their reserves have been somewhat depleted.
Frequency
You should water your succulents roughly once a week if you are keeping them outside or in a greenhouse throughout the summer. The soil should be getting close to being completely dry, but not for too long.
Technique
Make sure to water established plants until their deepest roots are submerged in water. As a general rule, keep watering until water begins to emerge from the pot’s bottom. Deep watering will encourage strong root development, which will make the plants healthier. A less established plant and a shallow root system are the results of frequent, superficial watering.
But succulents don’t like to stay in moist environments for too long. Drainage is crucial, thus. In the ground, adding some pumice to your soil will improve drainage. A well-draining potting mix and a container with a drainage hole will work for your container garden.
Here is an illustration of two identical haworthias that were cultivated using various watering techniques. Lightly watered on the left, intensively watered on the right till the water flowed out of the bottom of the pot. The end result is that the haworthia on the left is smaller and its root system is less established. The haworthia to the right is full, has a solid root structure, and is beautifully colored green.
Timing
The optimum time of day to water succulent plants in the summer is in the early morning before temperatures rise. You may prevent hot water from sitting in the crown of your plant and perhaps scorching it by avoiding watering in the afternoon when temperatures are at their highest.
If watering in the morning is not possible, watering in the evening is an option. This is a bad idea to do in the cold, though. In the colder months, keeping the plants damp all night makes them more vulnerable to fungus. To be safe from such cultural concerns, we err on the side of keeping our plants a little dry over the winter.
Exposure
Remember that, like us, succulents require a little more sun protection during these hot summer months. If their leaves are left in the sun for an extended amount of time, they will burn. We advise keeping your succulents in a position with dappled shade from a tree or under an awning for partial shade.
The health of your succulent depends on water. A vigorous plant that is more resistant to pests and disease will result from good root health and good watering. Additionally, the other living organisms in your garden need on water. Bees, butterflies, and hummingbirds are just a few of the pollinators that depend on the water we water our plants with.