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Oh, No, My Succulents Froze!

Can succulents recover from a hard frost? It depends. Here’s a southern California nursery’s display garden before nighttime temperatures dropped into the mid-20s F:

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Here’s the same Euphorbia ammak ‘Variegata, after the frost:
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Likelihood of recovery: Nil. Too much of the tissue was damaged. But what about the Euphorbia tirucalli ‘Sticks on Fire’ behind it? It’s hope of recovery is excellent because only the top growth froze. It protected the stems underneath, which are still healthy.

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If something similar has happened to your plants, succulent or otherwise, once all danger of frost has passed, prune the dead top growth and the plant will be good as new…except smaller, of course!

How about the frozen aeonium below? Pretty much hopeless. But look a the Sedum ‘Angelina’ surrounding it. It’s a succulent too, and perfectly fine!
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Why does frost kill some succulents and not others? A lot has to do with where a particular kind of plant originated. Succulents, which store water in their leaves to survive drought, are mostly from dry, hot climates. But some are from dry, cold climates. See my Wall Street Journal article on this topic.

Related articles and info:

An excellent book about succulents that survive freezing temps is Hardy Succulents, by Gwen Kelaidis, illustrated by Saxon Holt.

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My books also have info on growing succulents in challenging climates and how to protect them from frost and excess rain ~

 

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How to Keep Succulents Happy Indoors

If you need (or prefer) to grow succulents indoors, outfit a basement, sun room, spare room or alcove with tables and shelves that can withstand moisture, plus lights and a fan that run on timers. Fortunately succulents need very little water. Dribble a little at the base of each plant every three weeks or so, enough to hydrate the roots but not so much it puddles on the floor.

Place your succulents near a window. Maximum sun exposure is on the south and west sides of your house. The farther north you live in North America, east will provide bright light, but not enough for crassulas, echeverias and aloes to maintain their red hues. [Read more] 

OR…

Install grow lights. Experts in growing succulents in gray-sky climates recommend T-5 grow lights.

Agrobrite FLT44 T5 Fluorescent Grow Light System, 4 Feet, 4 Tubes, about $120 on Amazon.

 

Create a “light island.” Shown below is arguably the ultimate indoor plant-shelf unit. Made of lightweight, powder-coated aluminum, it has adjustable lights with energy-efficient, full-spectrum bulbs; plastic drip trays; and wheels for easy positioning. Three shelves provide 18 square feet of growing space. From Gardener’s Supply Co.; about $600. 

Get a timer which automatically turns the lights on at, say, 7 a.m. and off eight hours later. I like this one, below, because it has multiple outlets:  Titan Apollo 14, about $26. 

Watch the temperature. If it falls below freezing (32 degrees F) many succulents may show long-term damage (or die). This indoor thermometer is digital and also has a humidity gauge. But what I love about it is that it keeps daily high and low temps for 24 hours!

AcuRite 00613 Humidity Monitor with Indoor Thermometer, Digital Hygrometer and Humidity Gauge Indicator, about $10 on Amazon.

Wonder why your otherwise healthy succulent is stretched and doesn’t flower? Go to: Why Doesn’t My Succulent Bloom?

 

 

 

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Agave Snout Weevil Prevention and Treatment

VIDEO: Agave snout-nosed weevil (30 sec.)

The agave snout-nosed weevil is a half-inch-long black beetle with a downward-curving proboscis that enables it to pierce an agave’s core, where it lays its eggs. Grubs hatch, consume the agave’s heart, then burrow into the soil to pupate. The weevil (Scyphophorus acupunctatus)—once prevalent only in desert regions and Mexicois spreading rapidly throughout the US and abroad, earning it the dubious distinction of being one of the “Top 100 Worst Global Invasive Species.”

The agave in the middle shows signs of snout weevil infestation. This a block from my home (eek!)

According to the Global Invasive Species Database, “Scyphophorus acupunctatus is becoming a major pest of native Agavaceae and Dracaenaceae species worldwide. From Mexico, it has decimated populations of Agave crops there, in particular those used in the tequila industry. The importation of ornamental Agave plants worldwide has facilitated S. acupunctatus to establish in many parts of the world, particularly in Central America and the Caribbean, in Africa, Asia and South America.”

Is your agave infested? Look for damaged tissue where leaves meet stem. The lowest leaves will appear wilted, and may slope unnaturally downward while the center cone remains upright. The plant, no longer anchored by roots, will rock when pushed. When an infestation is well underway, it’s possible to shove the agave over onto its side. It’ll break at soil level, revealing a mushy, foul-smelling core infested by plump, squirming, half-inch, cream-colored grubs with brown heads.

Agave snout weevil

Above: an agave’s grub-eaten core resembles a sponge.

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Above: Close-up of a snout-nose grub.

In my YouTube video, “Agave Snout Weevil Prevention and Treatment,” I demonstrate how to inspect nursery agaves, show resistant varieties, and interview agave expert Kelly Griffin at an infested colony of Agave americana. Kelly also talks about applying a systemic insecticide as a prophylactic (preventive) option.

How one homeowner does it: Succulent collector Jeanne Meadow is well versed in the fauna and flora of her large garden in Fallbrook, California, midway between Riverside and San Diego. Jeanne, an ace researcher, has become an expert on the agave snout-nose weevil. She says people tend to assume most nursery plants are pest-free, yet that’s the primary way snout weevil enters gardens. When an agave in her garden shows signs of infestation, she removes it and every plant for several feet surrounding it. Then she sifts the soil and picks out grubs and beetles. “It’s a huge undertaking,” Jeanne says. “Fortunately they’re slow crawlers.”

To remove a diseased agave, here’s Jeanne’s method:
1. Place a tarp around the plant.
2. Position a wheelbarrow nearby. Make sure the tarp covers the ground between it and the agave.
3. Dig up the agave and put in the wheelbarrow.
4. Dig out more dirt to a depth of 12 inches (deeper if you find grubs) and about 12 inches from where the base of the plant was.
5. As you transfer the soil to the wheelbarrow, inspect it for grubs and weevils.
6. The beetles “are hard to crush,” Jeanne says. “I use a hammer.”
7. Take the wheelbarrow to a paved area, like your driveway, so if beetles escape they’re easy to spot.
8. Transfer into heavy-duty trash bags, sprinkle contents with insecticide, and triple-tie.
9. Seal any rips with duct tape.
10. Drench the soil where the agave was with insecticide.

Aren’t insecticides bad for the environment? Although neither Jeanne nor I advocate inorganic pesticides, and we certainly aren’t licensed pest control experts, we strongly believe that the responsible thing to do is to share knowledge with others based on research and personal experience, and to do what we can to prevent the beetle from spreading. “This is an emergency situation,” Jeanne says. “The pest is spreading like crazy and has to be brought under control.” According to agave experts, growers, and pest management specialists, the best approach is preemptive: drench the soil around healthy agaves with a systemic insecticide that has imidacloprid as the main ingredient.

Hire a licensed pest control expert. The going rate is $175/hr., but you’ll know for certain that everything is done safely and protects the environment while eradicating the pest from your property. One in the San Diego area is Chris Mizoguchi, chrisagpestcontrol@hotmail.com.

How to preventatively treat your agaves. The goal is to drench the agave’s roots. Twice a year, in spring and fall, here’s what I do:

1. The night before, soak (hose-water) the soil at the base of each agave to aid penetration.
2. Read and follow the label directions. Be sure to wear gloves and protect your skin and eyes.
3. To mix the solution, I use a hose, a 3-to-5 gallon bucket, and a stick for stirring. Product labels don’t say how much concentrate per gallon of water for agaves, so I go with the ratio for shrubs. (If using Compare-N-Save Systemic Tree and Shrub Insect Drench, it’s 3 oz. per foot of height per gallon of water.)
4. Agaves naturally funnel rainwater water to their roots, so if you slosh the solution where lowest leaves meet the core, you’ll effectively drench the soil below them at the base of the plant.

Note: Avoid doing this in temperatures above 80 degrees F. High temps diminish the insecticide’s effectiveness and may even harm plants already stressed by heat. 

Don’t panic, but do pass the word. It’s only a matter of time before weevils in neighbors’ agaves find their way to yours (and vice-versa). The unfortunate reality is that agave owners who do nothing are inadvertently aiding the proliferation of a serious pest, and may incur the expense and inconvenience of removing prized, immense and spiky plants. I suggest you:
— Send close neighbors a friendly email with a link to this page.
— Post about agave snout weevil on your neighborhood’s online forum. If possible, include a photo of an infested agave.
— Copy-and-paste part or all of this into an email to the editor of your community newsletter. (All I ask is to be credited. With, of course, a link.)

Don’t assume your agaves won’t be affected. Although snout-nosed weevils can’t fly (yes, there are such things as flightless beetles), they sure can walk. I first suspected that snout-nose had arrived in my backcountry community northeast of San Diego when I noticed a collapsed Agave americana in a friend’s garden. I could barely believe it. She lives atop a rocky hill surrounded by acres and acres of native chaparral. Either the weevil had arrived via infested nursery stock (on a different agave most likely, seeing as the sick plant was part of an old colony), or it had walked in. I’ve since observed that it takes a captive weevil ten days to die despite receiving no water nor food. The entire time, it was mobile and capable of traveling 4 inches per second. Had I released it, it easily could have gone several blocks (at least). It also was a surprisingly good climber.

Consider: If a dying agave hosts dozens of grubs that turn into beetles, and if each takes off in a different direction, one or more will certainly find another agave.

A tiny concern. If your goal is to kill snout weevils before they spread, a systemic ought to do it, but it’s uncertain how much damage the puncture hole causes. The weevil is a vector (carrier) of Erwinia carotovora, a micro-organism that decomposes plant tissues, enabling grubs to easily consume it. I’m hopeful, and it seems likely, that the bacteria doesn’t go deeper unless spread by live grubs. Moreover, as I mention below (see “Good News”), bitten agaves have been known to recover.

GREEN ALERT: Insecticides kill beneficial insects as well as pests and may disrupt your garden’s natural predator-prey balance. Snout weevils have coexisted with agaves for millennia and are naturally preyed upon by reptiles, birds and mammals (though the spines that protect an agave from predation also protect the weevil). Systemics, as the name implies, transmit insecticides through a plant’s system, so that any bug that eats it dies. Some studies have indicated that bees and birds are not harmed by the nectar of treated plants, and that animals farther up the food chain are not at risk. Use sparingly and follow label directions. Don’t pour this (or for that matter, anything inorganic) into drains or gutters.

Weevil control without pesticides. Remove an agave at first sign of infestation and sift grubs and weevils out of the soil. (Feed them to your chickens or put them out with the trash in sealed plastic bags.) Don’t plant agaves in that part of your garden again, and watch your other agaves for signs of infestation. It’s possible that beneficial nematodes may be effective. They do kill larvae, but I’ve yet to find out if they’ll work against snout grubs. (Check back.)

Earthworm castings destroy beetle exoskeletons, advises Pat Welsh, author of Pat Welsh’s Southern California Organic Gardening: Month by Month. In Jan, 2018, in response to this post, she wrote: “Imadacloprid is killing bees. It is one of the worst ever pesticides and will end up killing us also. Instead of that, purchase earthworm castings and spread them on top of soil surrounding agaves. Keep it up. Earthworm castings kill all insect pests and are a great barrier to the ones that live in the ground under plants. Weevils walk on top of soil and cannot cross earthworm castings or they die. This is because earthworm castings contain chitinase, an enzyme that destroys chitin. The exoskeletons of insects are made of chitin.”

Good news ~
Agaves treated early in an infestation may recover, providing there’s adequate meristem tissue to regenerate new growth. (An agave’s meristem cells are at the core, or heart, where leaves join roots. It’s prime grub fodder.)
An organic control currently being tested is a pheromone trap designed to attract adult beetles in search of mates.
— Weevil-resistant Agave varieties do exist and are being selected and cultivated. (Sometimes you’ll see seemingly unaffected plants alongside diseased ones.) Tissue-culture labs make it possible to produce quantities of plants over a short period of time, which is likely the future of commercially-sold members of the Agaveaceae family.
— The weevil seems less inclined toward those with thin, flexible leaves, such as Agave attenuata; those with tough, hard-to-pierce leaves (such as agaves desmetiana, murpheyi, parryi, lophantha ‘Quadricolor’, ‘Sharkskin’, triangularis, victoriae-reginae and vilmoriniana); and those with slender, nonjuicy leaves such as agaves bracteosa, filifera and geminiflora. See photos on my website’s Agaves page.

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In the meantime…

Plant agaves bare-root. Before planting, remove an agave from its nursery pot, set the plant (root ball and all) in a wheelbarrow, and hose the soil from the roots. Examine the plant for beetles and puncture holes, and the soil for grubs. If a plant is infested, destroy it and inform the source nursery. Jeanne notes that when chased, weevils head back to the agave for shelter. “They don’t try to escape from the wheelbarrow.” Btw, after observing grubs kept alive in soil-filled jars, Jeanne says that when deprived of an agave to feed on, grubs don’t pupate (turn into weevils).

Grow agaves in pots. In areas where snout weevil is known to be active, plant agaves in containers like the urns shown here. You’ll know that the soil is OK because it came from a bag; you can easily get rid of infested soil should beetles show up; and when you apply a preventative drench, only the soil in the container is affected. Additional advantages are that pots elevate agaves for better viewing, enabling them to serve as garden focal points even when small. Potentially immense, pupping agaves (such as A. americana species) grow more slowly in containers, which also serve to corral their offsets.

The big green agave at left is likely a hybrid of A. salmiana; at right is A. franzosinii. In the foreground is what Jeanne Meadow calls “snout-weevil candy”: A. americana ‘Mediopicta Alba’.

Watch susceptible plants. Keep an eye on all your agaves, especially mature ones about to bloom, because they’re loaded with weevil-attracting carbohydrates. The pest seems to prefer specimens of Agave americana and its variegates (striped varieties), as well as closely related Agave franzosinii (one of the largest agaves). Reportedly, it may infest other genera in the Agavaceae family, such as Nolina, Beaucarnea, Yucca, and Furcraea. I’ve heard, but have yet to confirm, that it also attacks Mexican fence post cactus (Pachycereus marginatus) and possibly barrel cacti — but symptoms may simply be due to a different bug. After all, it’s a Pandora’s box out there.

Don’t give up on agaves! “Snout-nose shouldn’t discourage anyone from planting agaves,” Jeanne says. “There IS hope, and my garden is a great example of that.” She adds that the imidacloprid drench—which degrades over time—has had no apparent impact on her garden’s overall health and ecosystem, “including its population of beneficial insects, reptiles, birds, and amphibians.”

More info:

UC Nursery and Floracultural Alliance Regional Report, Spring 2016, “Agave Pests

Global Invasive Species Database

Desert Botanical Garden, Phoenix, AZ

Pam Penick’s blog post: “Evil Weevils! Agaves Under Attack in Austin”

Tropical Texana blog: http://tropicaltexana.blogspot.com/p/agave-weevil-eradication.html

View my 7-minute YouTube video, Agave Snout Weevil Prevention and Treatment

Note: This post first appeared in August, 2016. I’ve updated it several times, most recently in Jan., 2018.  I welcome your comments. — Debra

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Watch How You Water!

OK, we all know that succulents are low-water plants. But they’re not “no-water” plants. Although they may survive without irrigation during the heat of summer, they’re unlikely to be lush and healthy.

I suggest that you ~

— Check your automatic irrigation system. Trust me, it needs it, and maintaining it can mean life or death to prized plants. Watch for leafy growth blocking sprayers, clogged riser heads, and plugged drip lines.

— Pay keen attention to soil moisture during heat waves and desiccating winds.

— If the root zone goes dry, supplement auto irrigation with hose watering. (See my canary-in-the-mineshaft way to evaluate evaporation in my latest video, Succulents, Sun and 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.

— Take the opportunity, when hose-watering, 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.

What about potted succulents?

From my website’s FAQ’s:  Aim to keep soil about as moist as a wrung-out sponge. About once a week should do it. Water thoroughly to soak the roots and flush salts. Let common sense prevail: Water more during hot, dry spells and less or not at all during periods of high humidity, cool temperatures and rain.

ALSO SEE: Page 56 of Succulents Simplified, pp. 219-222 of Succulent Container Gardens, and pp. 134-135 of Designing with Succulents (second edition). 

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Summer Care for Your Succulents

Don’t let midsummer heat, sun and dryness damage your succulents! 

If you live in an arid climate and grow succulents in the open garden (as I do), I recommend you ~

— Watch and enjoy my latest video: Succulents, Sun and Summer. On an 89-degree day I give a tour of my garden, noting what’s in bloom, lookin’ good (or dreadful), and checking the health of succulents small and large.

— Move sun-sensitive potted succulents into the shade: haworthias, gasterias, euphorbias, faucarias, sansevierias, echeverias, and anything light-colored or variegated.

— Give aloes and crassulas enough sun to turn bright colors but not so much that leaf tips shrivel or burn.

— Shade horizontal stems of trailing aloes, senecios, othonna and the like. Sunburn hinders stems’ ability to transmit moisture from roots to leaves.

— Create temporary shade structures from old window screens.

— Or use leafy branches trimmed from trees (insert in the ground next to a plant you want to protect, on the side that gets the most sun).

— Evaluate garden areas in need of shade, and plant trees when the weather cools in the fall. And for that (drum roll) I have another new video: Twelve Low-Water Trees for Succulent Landscapes.

How to Fertilize Your Succulents

Time to Feed Your Succulents

Fertilize succulents when they’re emerging from dormancy and beginning their annual growth spurt, which for most is spring. A light feeding of manure tea, diluted fish emulsion, or a balanced fertilizer will help them grow lush and lovely. See my video. 

Link to video of Debra video about fertilizing succulents

What do I use?

For container-grown succulents, one Moo Poo tea bag per three gallons of water, steeped overnight.

Uh…”Moo Poo?”

Yes. Otherwise known as Authentic Haven Brand Soil Conditioner, Premium Manure Tea. (Btw, I’m not getting paid to endorse it.)

What about in-ground succulents?

I apply Ironite before a winter rainstorm (I know, it’s too late) and a balanced granular fertilizer in March.

How to apply?

Water the plants, then pour manure tea until it begins to run out the pot. In the garden, spread granular fertilizer and water it in.

What kind of granular fertilizer?

The brand doesn’t matter, but the ratio of N (nitrogen), P (phosphorous) and K (potassium) should be equal.

How much?

Succulents need about half the dose recommended on the package.

Is there an organic alternative?

Apply a topdressing of compost. I like fish emulsion, too, for both pots and in-ground plants (diluted half strength).

How often?

Once in spring when daytime temps stay above 60 degrees F. Then again in June.

What if I don’t feed my succulents?

No biggie, but they’ll look and perform better if you do.

Is it OK to fertilize more frequently?

That’s what many growers do. A little bit of fertilizer with every watering promotes rapid growth. However, such plants are considered “soft” (a nursery term) rather than “hard,” meaning tough. It’s a trade-off. I grow my succulents hard to help them endure the vicissitudes of the open garden.

Anything else?

Soils vary from region to region and even within a garden. The best way to know what your soil lacks is to have it tested, but it’s common sense that succulents growing in, say, oak leaf mulch are getting ample nutrients and don’t need fertilizing; those living in pots for years or growing in decomposed granite probably do.

No other soil amendment is as widely used by succulent growers and collectors as pumice (crushed lava rock). Here’s why. [Read more]

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Post-Rain Must-Do’s for Succulent Gardens

Rain at last!

Could the California drought finally be over? Well, no. It’ll take hundreds of years for underground aquifers to refill. The snowpack isn’t adequate for our future water supply. On the bright side, our gardens are looking glorious…even those with mainly drought-tolerant plants. Perfect conditions for succulents are good drainage, annual rainfall less than 25 inches, low humidity, and temperatures above freezing.

Check for:

Succulents with rotted leaves. Remove mushy leaves before rot spreads to the plant’s stem or crown. This and other concerns are addressed in my YouTube video, Oh No! Something’s Wrong with My Succulent! 

Drainage issues. If soil stays sodden and muddy areas remain long after a storm, roots may drown. Move plants to high ground, and install French drains.

Slope erosion. Create dams of rocks and diversion channels, and add gravel or mulch to diffuse the rain’s impact.

Stagnant water. Check pots, bins and barrels. If they’ve filled, dump the water before mosquitos find it and breed.

Weeds. Wherever soil is exposed to sun, weeds WILL sprout. Get them when small. All too soon they’ll have deep roots, go to seed, and look you in the eye.

Seepage. Check your home’s basement. Mine used to have an inch or two of standing water whenever the ground became saturated during storms. A few years ago, a friend suggested a simple solution: Coat the concrete blocks that form the basement’s walls with a special paint that prevents seepage. Works great. Any home improvement store carries it.

Shop for plants.  Now’s a good time to accumulate plants you want to add to your garden. Rain-soaked ground is soft and easy to dig. Early spring is the best time to establish new plants, after all danger of frost has passed (here in Southern CA, that’s mid-March). Plants will take off in spring and won’t have to contend with summer heat while putting down roots. Don’t delay; if your garden is like mine, when the soil dries, it’ll be as hard as concrete.

Take photos as what-to-do reminders. When the weather clears, such issues are easy to forget.

The bottom line: Succulents are opportunistic when it comes to rain. Given adequate drainage, they absolutely love it!

Related articles:

Spring in my succulent garden: Flowers wow with bold, hot hues 
My spring garden’s most vivid blooms are those of succulent ice plants. Aloes, bulbine and numerous arid-climate companions are bright and beautiful from March through mid-May. Increasing temps tend to put the kibosh on [Continue reading]

YouTube Videos:

Post-Rain Must-Do’s for Succulent Gardens Debra's post-rain must-do's video

How to Protect Succulents from Frost

Frost cloth protects jades and other vulnerable succulents in my garden

Frost cloth protects jades and other vulnerable succulents in my garden

Depending on the type of succulent, how low temperatures drop (water freezes at 32 degrees F), and how long the cold snap lasts, “frost tender” succulents may show damage just on leaf tips or collapse into mush.

When moisture in the cells of a vulnerable plant freezes, it expands and bursts cell walls. A few succulents have a built-in antifreeze, and survive temperatures well below 32 degrees F—below zero, in fact. But these are the exception, and tend to be in the genera Sedum and Sempervivum.

Crassulas, aeoniums, euphorbias, and kalanchoes are among the most tender succulents. The majority of aloes, echeverias, cacti and agaves can go a few degrees below freezing for a short period.

Unlike most agaves, thin-leaved Agave attenuata is the canary in the mine shaft where frost is concerned. After a brief exposure to 32 degrees, it looks like this.

Unlike most agaves, thin-leaved Agave attenuata is the canary in the mine shaft where frost is concerned. After a brief exposure to 32 degrees, it looks like this.

Check the forecast, and if there’s a frost advisory for your area, cover susceptible plants with frost cloth (sometimes called garden cloth, frost blanket or floating row covers) or old bedsheets.

When determining if a tender succulent needs to be covered, I sometimes stand over it and look up. Plants beneath eaves or tree branches are not as vulnerable as those open to the sky.

Cold air is heavier than warm, and flows down slopes and collects in low spots. Consequently, succulents in swales are more at risk than those atop berms.

You may have heard that Christmas lights raise the temperature a few degrees. Yes, if they’re the old-fashioned kind. Those sold nowadays (LEDs) don’t generate heat.

Wait until spring to trim damaged tissue. It’ll help protect the plants from further damage.

Watch how I cover my own tender succulents in my new video, “Protect Your Succulents from Frost.”

Succulents and Too Much Rain, A French Solution

I like how the Jardin Zoologique Tropical in southeastern France keeps their succulents from becoming waterlogged during seasonal rainstorms. Corrugated fiberglass panels atop metal bars tent the plants so excess rain doesn’t soak the soil.

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The structures are tall enough to allow good air circulation, and the panels are translucent, enabling maximum sunlight to reach the plants. The covers, which have a horizontal metal rod atop them so wind can’t lift them, also protect tender succulents from frost.

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Notice, too, that the plants grow in rocky, elevated, sloping soil, so water drains away from the roots.

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You might do something similar in your own garden with a patio umbrella secured in a concrete base. But keep in mind that the water has to go somewhere. The French garden’s panels channel rain onto the gravel roadway nearby.

Btw, this public garden, located near the village of La Londe-les-Maures, is deservedly proud of its succulent collection. Here’s a description from the website, courtesy of Google Translate. The common names of the plants are charming.

Our plant collection is rich in many varieties of succulent plants: agaves, aloes and euphorbias. Every season their blooms transform the gardens. We regularly introduce little-known species and observe them for their ornamental potential. Perhaps the best known are cacti native to the Americas. We grow several species hardy in our climate. Some are globular, like the famous “mother-cushions,” others are elongated, cylindrical and commonly called “candle cactus.” Visitors easily identify the “prickly pear,” also called “Mickey Mouse ears” or “cactus rackets.”

(Photos used with permission.)

 

Will Frost Hurt Your Succulents?

Succulents from certain parts of the world, notably lower elevations of South Africa and Madagascar, are vulnerable to freezing temperatures. If the forecast is for temperatures below 32 degrees F, throw a sheet over your crassulas, kalanchoes, aeoniums, stem euphorbias and aloes before nightfall and remove it in the morning. See how I do it in my own garden in this video, Protecting Your Succulents from Frost.

Frost that nips your succulents may turn their leaves brown and unsightly. How do you know if a plant is worth keeping? It may depend on how patient you are. Even badly damaged succulents are surprisingly resilient, but it may take months before they look good again.

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Temperatures below 32 degrees caused the fluid in this aloe’s cells to expand and burst, irreparably damaging the tips of many of its leaves. Luckily for the plant, those same leaves protected its core, which is still green and viable.

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If you decide to try and salvage a succulent with this sort of damage, wait until the weather warms in spring, then snip off the dead tissue. Because new growth forms from the center of the rosettes, pretty soon the old leaves will be barely noticeable.

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And now you know that this is one succulent that needs covering next time there’s a frost advisory for your area. Here’s how my garden looks when temps are predicted to drop below 32 degrees F.

Notice that Agave attenuata tucked beneath the tree on the left? It’ll be fine because the tree will protect it. The plants you have to worry about are those that are out in the open, with nothing above them. I sometimes stand over a succulent and gaze upward. If there are no tree limbs or eaves directly overhead, it gets draped. (I use old sheets. Several years ago a nongardening friend, stopping by for a visit, asked if I was doing my laundry.)

How do you know if you live in a frost-free area? Your neighbors grow Agave attenuata in their gardens, and the plants look fine. In my garden, this soft-leaved agave is the canary in the mineshaft where cold is concerned.

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It’s the first plant to show damage from frost in winter. A lot of succulents can handle cold below 32 degrees for short periods. But Agave attenuata will look like this the next day. This is a nuisance, but fortunately not fatal.

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See the healthy green part of each leaf? Wait until spring, then use scissors to trim off the tissue-paper-like frozen tips, cutting each leaf to a point. When you’re done, the damage will be barely noticeable. By summer new growth will have hidden the short lower leaves.

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What about a succulent that has frost damage only on its leaf tips? Don’t bother to trim them. It’ll lose those oldest leaves in a few months, anyway.

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Kalanchoes tend to be quite frost-tender. One similar to this melted to the ground in my garden at 27 degrees, and I assumed it was a goner. Fortunately I didn’t dig up the damaged plant and discard it, because a few months later…

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…it came back from the roots.

Jade plant is another widely cultivated succulent damaged at 32 degrees. The leaves turn squishy and putty-colored. This is not pretty, but if the plant’s stems are firm, it will recover and grow new leaves.

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Actually, the jade plant in the photo was not a victim of frost. You know the term “frost burn?” This plant actually was burned…by a wildfire. The only indication that it wasn’t “burned” by frost is that frost tends to damage the top of a plant. This one was scorched on the side closest to the fire. (Which just goes to show, succulents cook rather than burn, but that’s a different post.)

If you live in an area where you can’t grow most succulents in the ground because it gets too cold, take heart…there are varieties that will do well for you. I recommend this excellent book: Hardy Succulents by Gwen Kelaidis, photos by Saxon Holt.Screen shot 2016-01-05 at 7.59.00 PM

Go to my posts: Four Ways to Overwinter Your Succulents
How to Keep Succulents Happy Indoors

Learn more in my book, Designing with Succulents (2nd ed.):
— Cold-Climate Succulent Gardens, pp. 111-113
— Cultivating Succulents in Challenging Climates, pp. 143-148