Succulent plants are very recognisable due to their water filled, fleshy leaves and stems but not all succulents are alike. They can be different in terms of their appearance, growth habit, watering requirements, light requirements, propagation techniques, care requirements etc.
Some succulents can also drop leaves even at the slightest touch or when moved while others are super sturdy. Leaves falling off is a very common concern among our customers.
So why do succulent leaves fall off and are succulents dropping leaves something to worry about?
Some succulents drop leaves very easily as that is how they spread, some are just a tad delicate but then in other cases it can be a sign of the plant being sick (rotting, fungal infections etc.)
Let’s have a closer look at 7 different reasons why succulents drop leaves and some signs to spot trouble.
As mentioned above, there are succulents out there that seem to drop leaves just by looking at them. Some of the worst offenders in our collection are Sedum Rubrotinctum species, Sedum Dasyphyllum, Sedum Morganium, most Graptopetalums, Graptoveria and Graptosedum Species, Echeveria Perle Von Nurnberg & Purple Pearl, Echeveria Lola, Haworthia Cymbiformis, Peperomia Graveolens & Asperula.
The good news is that nearly all these plants (except for the Peperomias and Haworthia) can be propagated by leaf and so if you manage to set one loose it can be put in a dry and bright (not sunny) spot or on top of soil in a shaded spot. In about a month or so, new plants and roots will start emerging.
Although succulents are hardy and can grow in many positions from full sun to bright shade, most succulents will grow tall, leggy and their leaves will be more prone to falling off, if they are not in at least 5-6 hours of sun. Some succulents are shade lovers (Haworthia, Sanseveria, Gasteria etc.) but the great majority need exposure to direct sun to stay compact, colourful and happy. Unfortunately, there is no one size fits all and the amount of sun also depends on your particular climate as well as the species of plant & whether the plant is grown in pot or ground (read our blog on ‘Can Succulents Die From Too Much Sun’ for more info)
Even the succulents mentioned in 1. can be made less sensitive and less prone to leaves falling off by being kept in as much light as they can take. More sun/light=more compact succulents.
Every spring succulents start waking up from their winter dormancy (unless they are summer dormant like Aeoniums, for instance) and race ahead with new growth. This new growth can be quite sensitive and as a result, the leaves may be a little bit more prone to falling off, if the plant is handled too much. We notice this especially in Sedum Dasyphyllum- young plants are extra sensitive to the touch until the root system is well developed. We usually do not post plants such as Dasyphyllum until the roots have reached the limits of the pot as this is when the new growth will slow, the plant will grow tighter and the leaves will become a bit harder to dislodge.
Extra growth also happens when a succulent is re-potted into a bigger pot which will result in more sensitive leaves in some species.
This is quite natural and not much can be done about it.
Although many succulents need daily sun exposure to stay compact and colourful, during heatwaves that see temperatures soaring well over 35 C (95F), direct sun can damage the more touchy succulents, especially if they are planted in a dark coloured pot. Sun damage manifests itself in a few ways, one of them being leaves falling off the plant. This can happen very suddenly.
Our nursery is based in sunny Australia and in recent years the heatwaves have been getting hotter, more frequent and longer lasting. It is not unusual to have temperatures over 40 C (104F) at which point the great majority of plants exposed to direct sun suffer as do humans and other animals (it is very unpleasant being outdoors in a 40C heat). Plants in the ground have a better chance of surviving due to their roots staying cooler while succulents in pots have to put up with hot roots which can stress them to the point of dropping leaves and rotting as a result. We have seen this happening many a time during extreme heatwaves. Some plants are tougher than others and will get through extremes like this without a problem, even if in pots (Graptopetalum Paraguayense springs to mind) while others (Orostachys Iwarenge, Aeoniums, small leaved Sedums or some hybrid Echeverias etc.) will not tolerate even short exposure to very hot sun.
Simple steps can be taken to protect your succulents from extreme heat. If you only have a couple of pots, they can be moved to a bright but shaded spot for the duration of the heatwave. If the collection is too large to move around or includes large & heavy pots, shadecloth (our most favourite is 30%) can be pitched over them. The simplest way is to bang 4 pickets/stakes in put the cloth over, pegging it to the pickets so it doesn’t blow away. Also keep in mind the movement of the sun. Umbrellas can also be placed over pots or gardens.
Rot in succulents is usually only noticed when the leaves start dropping/ rotting. Rot in succulents can happen due to too much water, potting mix that is heavy and holds too much moisture, high humidity, heat (as discussed above) or frost.
Rot starts in the roots, moving through the stem and into the leaves, collapsing the whole plant in the process. The majority of succulents will start loosing their leaves, though some can just turn to mush.
There is very little that can be done to save a succulent suffering from rot. If caught early the part of the plant that has not yet rotted can be cut off and planted as a cutting or leaves not yet affected (they won't have any brownish bits at the base, where they are attached to the stem) can be pulled off to start new plants via leaf propagation.
To prevent rot succulents should be planted in well draining potting mix, if kept in pots. Plants in the ground should never be planted in areas that can flood and stay under water for extended periods. The potting mix should be allowed to dry out between waterings and pots should be kept out of full sun during heatwaves.
Again, some succulents will behave differently in similar scenarios. For instance all our nursery succulents, bar about 5 varieties, are grown outdoors. They have survived heavy and frequent rains in the past without rotting. Having said that a lot of new hybrid succulents can be a bit touchy when it comes to too much moisture and so if buying a rare/ expensive succulent, it is always best to err on the side of caution with water or rain and only water once the potting mix has dried out properly.
Although it is pretty rare to have pests causing leaves to fall, we have seen it happen. Both Aphids and Mealy Bugs can cause quite a bit of damage to a plant, when an infestation is severe. The plant can get so stressed the leaves will start dropping. This is more the case with succulents that have thinner, less chunky leaves, like Aeoniums or some Sedums.
Slugs and snails also love succulents and can chew away at the base of the leaf.
Grubs too may stress a plant into dropping its leaves.
Preventing pests can be really hard, as many succulents are particularly attractive to Aphids and Mealy Bugs, even more so if ants are present. Ants farm, protect and spread these pests to new hosts.
There are scores of chemical pesticides that will kill pests, though, they will also kill beneficial insects and may be a threat to your health too. We recommend 70% rubbing alcohol solution for mealy bugs and pyrethrum based sprays for aphids and ants. Keeping tables and pots clean will also reduce the chances of pests finding a hideaway. Putting plants that are known to distract and repel pests with their smell nearby(marigolds, lavender etc.) is useful too. We like to keep a few pots of these plants in strategic locations to minimize the chances of pests finding our plants en masse. Another great, eco friendly way is to attract beneficial insects such as ladybugs, praying mantis, hover flies or parasitic wasps to the garden by planting plants they like (oregano, allysum, chives, basil etc.).
A lot of succulents are prone to fungal infections if they are over watered or if they are exposed to high humidity. The fungus will usually start as a series of dark coloured spots and will eventually cause the lower leaves to drop. Fungal infections should disappear once the humidity goes, but it is always a good idea to either prevent or treat plants that are affected as fungus can stay dormant and spread to other plants.
To treat fungal infections, fungicides are readily available in any garden centre but, like pesticides, they are likely to kill beneficial insects and microorganisms. During periods of rain and high humidity, using a fungicide every 2 weeks for prevention is recommended. Unfortunately there is not much that can be done to prevent this any other way, if you live in a humid and rainy climate other than having your plants in a plastic greenhouse with a dehumidifier.
We have found an eco- friendly fungicide recipe that works quite well as prevention https://www.abc.net.au/gardening/factsheets/organic-fungicide/9426514here. It uses oil, detergent and bicarb soda.