How to care for Aeoniums over winter

We know how much Aeoniums need protecting in winter. This guide covers the challenges we all face, from extreme weather and frosty nights and days to taking cuttings. Enjoy the read; we hope you find something here that helps.

Summer and winter colours

Aeonium ‘Blood’ in summer. The darker colouration comes from intense summer sunlight, and it is at its most extreme during heatwaves and droughts.

Aeonium ‘Blood’ in winter. You can see it is greener than in summer, and more open and full leaved, because the cooler months are when Aeoniums do their peak growing.

Light and temperature

Aeoniums need good light in winter to stay healthy and compact. Without enough of it, they grow leggy and become more vulnerable to pests and diseases.

Most Aeonium species come from the sunny Canary Islands, where being near the equator gives them good light all year round.

In darker, colder places like the UK, light levels dip, the days shorten and temperatures plummet, so they need extra care. Leaving them outside to fend for themselves isn’t an option in most of the UK. A greenhouse, porch or conservatory will shield them from harsh weather, and over winter they do best in full sun at between 6 and 12°C.

We grow our plants in bright glasshouses and polytunnels, which warm up when the sun is out, much like their natural habitat. Aeoniums grow faster when temperatures are above 15°C.

You may need to move your Aeoniums into a controlled environment, such as a polytunnel, or, if you are desperate, into your house. Indoors, light levels are far lower than they need and temperatures stay above 15°C, so the plant will suffer.

In a controlled environment, keep temperatures within that 6 to 12°C range. Higher temperatures cause leggy, unhealthy growth, and lower ones may lead to frost damage.

Light keeps Aeoniums looking their best all year, and more light means healthier plants, especially in cool conditions. Grow lights are a good way to add to it where natural light is limited, such as on a dull windowsill indoors, and a bright enough grow light can be the main source of light.

Pests and disease

Pest activity may drop as temperatures cool, but don’t let your guard down: pests are still around. Aphids, mealy bugs and sneaky caterpillars can hide among Aeonium leaves, so keep checking and remove any you find. Pests under the soil, such as vine weevils, feed on Aeonium stems, and it pays to catch them early. Signs include a shrinking rosette, excessive leaf drop, a soft stem base, or even the plant toppling over.

Mealy bugs

These little white bugs are among the most common succulent pests. We suggest picking them off with tweezers or a fine brush. You can also use neem oil or any bug clear spray.

Caterpillar

These critters like to hide and eat away at the centre of the growth point. To stop this, we suggest inspecting your plants every so often. They like to make web nests within the leaves, so be on the lookout for those.

Botrytis

To slow or stop the spread of this fungus, we have found the best approach is to increase airflow and keep the plants dry, as any water left sitting on the plant may cause it to develop. If you notice it early enough, remove all of the affected area.

Aphid, greenfly and blackfly

These small, soft bugs can be a real nuisance to get rid of. One day you think you’ve cleared them all, and the next it’s like you never touched them! We suggest a weekly or fortnightly douse of soapy water and a wipe with a fine brush.

Vine weevil grubs

These grubs are silent killers: they attack only the roots and stem, so by the time you notice them it can be too late. To prevent vine weevils, we suggest repotting your plants in late summer or early autumn and inspecting the lower stem and roots. This clears out any eggs and grubs before they can do real damage.

Protecting from cold temperatures

Frost is by far the biggest threat to your Aeoniums in winter, so protecting them from the cold comes first. There are a few ways to do it, including shelter, positioning and tools that keep the frost off.

Light ground frost can occur when the forecast is 5°C or below. At these temperatures, younger plants and some of the more tender Aeonium varieties, such as Aeonium tabuliforme and variegated Aeoniums, can suffer frost damage. In some parts of the UK, frosts can come any time from early October to as late as early May. The average first frost arrives around 6 November, so be as ready as you can before then.

In a heated greenhouse or conservatory, aim to keep temperatures above 5°C. In unheated spaces, we recommend our tried and tested fleece, which protects down to -10°C with two layers in dry conditions.

Keeping your Aeoniums dry also helps their natural frost defences, so they can withstand slightly lower temperatures.

Hard frosts can still be a threat in enclosed greenhouses, so watch the forecasts and act before temperatures drop below 5°C. Raising plants onto benches or shelves gives extra protection, as even slightly above ground level it can be a few degrees warmer.

In colder regions, insulate the greenhouse with horticultural bubble wrap, and consider using heaters to ward off extreme cold.

Cuttings

You can still take Aeonium cuttings in winter, as long as you have a bright, airy place to grow them in. We don’t recommend it for propagation, though, because wintry conditions are not the best for rooting Aeoniums. Spring and late summer are the best times for that.

Large, mature Aeoniums can be hard to move into a safe space because of their size and weight, and it can be difficult to know what to do with them. Taking cuttings can be a good way to preserve your beloved plant.

First, find an older stem to cut from your plant. Young cuttings don’t root very well in winter and may rot, so choose an older stem like the one in the image. You can tell it’s older from the woody, brown stem.

Use sharp, clean garden snips to cut a rosette with a 3-4 inch stem. Let the cutting callus over for 3-5 days in a cool, bright place. Don’t skip this drying step, as it helps prevent rot.

Once the cut end has dried, plant it in a 50/50 mix of multipurpose compost and horticultural grit or perlite. You can dip the cutting in rooting powder first to encourage roots, but you don’t have to.

Keep it in a bright spot with good airflow and keep the soil slightly moist, not too wet. It should root in 3-5 weeks.

Growth rate

In their natural habitat of the Canary Islands and northern Africa, Aeoniums are mostly dormant through the hot summer and do their fastest growing in the mild winter months.

In colder climates like the UK, their growth slows dramatically during the coldest periods. Here their peak growing period runs from April to late September, apart from midsummer. In winter, the average temperature is usually too low for fast, sustained growth.

You may notice plants kept indoors growing faster over winter than those outside. The heating in your house stimulates their growth, and without the right lighting that growth can turn abnormal and leggy. Keep the temperature below 15°C or increase the light levels to reduce this.

Dealing with extreme weather

In extreme cold, protecting Aeoniums outdoors or in an unheated greenhouse can be difficult. If a hard frost of -5°C or below is forecast, fleece on its own may not be enough to keep the frost away.

In these cases, it may be worth trimming off rosettes or harvesting entire plants and bringing them indoors.

During the cold spell, stand the cuttings in empty pots without soil in a dry, frost-free place until the hard frost passes. They can be kept without soil for long periods, as long as they are somewhere bright, airy, dry and cool. When the frost clears, put them back in their original spot.

If another cold snap comes, bring them back inside. By spring they are likely to have grown roots, and you can then pot them up in free-draining compost.

Wrong winter locations

Avoid putting Aeoniums in a garage, dark room or enclosed shed over winter. In places like these, they drop leaves faster and end up with leggy stems and untidy growth by spring, if they survive at all. These spots also attract pests, which do further damage. Keep your plants in bright, cool conditions with good airflow instead.

Watering and feeding

Your Aeonium needs less water and feed over winter than during the rest of the year, because lower temperatures and light levels slow its growth. On average we water every six weeks, and we stop feeding until spring. We want the plants to almost go to sleep over winter, as this makes them more tolerant of frost.

In the growing season we drench the soil, but in winter we give just enough to wet it, so it can dry out. Avoid watering the leaves, as this may spread fungus.

Let the soil dry out between waterings. Too much water in winter means the plant holds more moisture too, which isn’t good in freezing temperatures. If a frost is imminent, don’t water or feed at all.

Outdoors if you can, indoors if necessary

Outdoors

Growing Aeoniums outdoors in winter is more feasible in coastal regions and inner cities, where temperatures are milder.

Pots are better than open ground because you can move them into a sheltered spot when it turns cold.

Microclimates in the garden are ideal, such as spots near windows where heat escaping from the house keeps them warmer.

Cold weather can still leave them vulnerable, though, and on exceptionally cold nights a cold frame with fleece can make the difference between losing a plant and keeping it.

Protect your plants from winter storms and hail, which can damage the leaves. To prevent stem rot in the wetter months, pot them in well-draining soil and shelter them from rain. Feeding is unnecessary in winter and may even harm Aeoniums.

Indoors

Aeoniums can be grown indoors, but they need a bright, cool spot with good airflow.

The ideal would be a well-ventilated glasshouse with paraffin heaters, grow lights, fans to circulate the air and extra-thick fleece on hand, but of course not everyone has the means for this.

If natural light is insufficient, grow lights can help. Even small, inexpensive ones can be enough to get your plants through to spring.

Fans help too, by moving air between the leaves and reducing the chance of fungus.

You may notice lower leaves dropping off. If they are yellow and full of water, the plant is overwatered, so reduce watering or take the soil away. If they are dry, this is natural and nothing to worry about.

Selecting the right plant for your environment

Hardiness varies between Aeoniums, so choose one that suits your environment. Some, like Aeonium ‘Phoenix Flame’ or Aeonium ‘Emerald Flame’, can survive temperatures as low as -6 or -7°C. To find plants that suit your garden, look through the hardy section of our website.

Green zone: hardy to -15°C

Amber zone: semi-hardy to -3°C

Red zone: tender, keep above 3°C

Most Aeoniums don’t grow very well indoors and much prefer to be outside, so we don’t often recommend growing them in the house. But not everyone has outdoor growing space.

A. tabuliforme and some variegated varieties, such as A. ‘Sunburst’, can grow happily on a bright windowsill.

Fleece usage

Fleece is a very cost-effective way to protect your plants in winter.

It forms a barrier between the plant and the weather, keeping frost and rain off.

We use fleece at 5°C and below, as we have noticed the risk of frost goes up at these temperatures.

The fleece we use, which we also sell on our website, is strong, thick and durable. At 60 g/sm, it is 4 times more heavy duty than the regular horticultural fleece sold in garden centres.

That gives us confidence it will prevent frost damage, and because it is durable, it doesn’t develop the holes and rips that would let frost in to damage the plants.

In extreme cases, when -2°C is forecast, the ground temperature can fall as low as -7°C, and lower in cold pockets, so we take extra precautions against frost damage.

On nights like these, use a double layer of fleece over your plants and make sure there are no gaps for cold air to get through.

Pin the fleece down too, as even a slight gust can move it enough to expose the plants. Rocks and pegs will keep it in place overnight.

You can also use the fleece as a shield against rain and hail. It is water resistant and can keep your plants dry underneath.

It protects against frost much better when dry, so if it does get wet, dry it out again.

In heavy rain, use two layers with a gap between them: the lower one keeps the plants frost free, and the upper one keeps the lower layer dry.

Once the sun is up and shining on the area, you can remove the fleece and let the plants breathe. It is also a good time to check that no pests are sheltering in the warm blanket.

If the frost persists all day, with forecast temperatures not getting back above 5°C, keep the fleece on. In an area with full sun, the plants will get enough light underneath to stay happy.

The fleece can be left on for days at a time with little impact on the plants’ health, but let them breathe and see the sun when the weather allows.

Rescuing Aeoniums from winter darkness

Even after your best efforts to protect them, your plants may still have suffered in the poor winter weather.

After each frost, check your plants for frost damage, pests and rot. These problems are worse in winter, because Aeoniums grow more slowly and are less able to fight off disease by themselves. You can tell a plant has been damaged by frost from its darkened, wilted leaves.

If the entire plant looks frozen, it may be too late to save it, but it is worth cutting it back to see if it will resprout. If the stem is soft after thawing, the plant may be completely dead.

You may not be able to tell whether your plant is frost damaged until it has thawed, so wait until it softens and then take action.

Cut off any damaged areas and inspect the plant often to make sure rot doesn’t set in. The outer leaves are more exposed than the inner crown, so they are usually the first to be damaged.

The plant in the image had major frost damage, but not enough to kill it, and you can see the centre is still undamaged. Frost damages Aeoniums once the leaves freeze. Ice forms in the cells and expands, breaking the cell membranes and walls and killing the cells. The dead cells are then likely to rot in damp, cool weather and spread botrytis fungus very quickly, so remove them as soon as you can identify them.

Preparing for spring and flowering

As your Aeoniums get ready for the following season, you may notice them starting to flower, if they are going to. This usually begins with the rosettes changing shape, often noticeable as early as November, ahead of flowering in spring. Once the warmer weather takes hold, feed gradually every 10 days with a well-balanced fertiliser to encourage a more impressive display. The flowers last a long time and are a good source of nectar for bees, butterflies and other insects, especially outdoors in a sunny spot.

Thank you for reading!

If you have any other care questions, email us at info@surrealsucculents.co.uk and we will be happy to help.

You can find more of our care guides in the Plant Care & Advice section.

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