Aphids are an incredibly annoying pest as they tend to appear in large numbers overnight and completely swamp some succulents.
My plant nursery deals with Aphids every Spring, Autumn and Winter and I have tried an incredible amount of treatments over the years to find the ultimate solution.
The good thing is Aphids are quite easy to control and on some plants they don't cause any damage at all. To find out how to get rid of Aphids fast, scroll down to the bottom of the article. To learn more about aphids and different types of control, keep reading.
What are aphids?
Aphids are small, soft bodied insect that can differ in size and colour. They have six legs, small head and wide body. Aphids can be found round the world and are a very common pests for all cultivated plants. There are some 5000 species of Aphids that have been identified.
The colours of aphids I have come across on succulents in our nursery are shades of green, orange, black and black-orange. I believe there are other colours too. Aphids vary in size and can be almost invisible to a couple of millimetres.
Aphids breed incredibly fast and females have the ability to give birth to live nymphs, some of which may already be pregnant themselves! This is how they manage to overwhelm plants very quickly. A few female Aphids can wreak havoc.
Some aphids also have wings and can fly to new plants that are not within crawling distance and can spread rapidly to new plants.
How do aphids damage succulents?
Aphids suck the sap out of succulents which weakens the plants, can deform leaves and mark the foliage. Furthermore, they excrete a sticky sap or ‘honeydew’ that can stick to the leaves and discolour them.
None of this damage is going to heal. Once the plant is marked or a leaf deformed, it will stay there permanently. The good news is that succulents just tend to grow out of this damage and not all succulents get affected badly even if there are many aphids.
How do I know I have an aphid problem on succulents?
The first sign of an aphid problem are tiny little bugs that do not move, usually sucking on the most tender growth (young leaves, center of the rosette, flower stalk).
Second sign are ants. Where there are aphids on succulents, there will usually also be ants. Some succulents will also have the sap discolour the leaves, making it look like parts of the leaf are wet or oiled. This will be particularly visible on succulents that have a dusty coating of farina.
At first only a couple of aphids will be visible, but they can take over at lightning speed if they are not killed immediately. Most people notice there is an aphid problem once there are quite a few of them and they are highly concentrated on new growth and also hiding on the bottom side of the leaves.
Sometimes aphid invasion will go unnoticed, especially if they are green and feed on plants of the same colour. Only when there are black marks from the puncture wounds as the plant grows, will they become apparent.
What is the relationship between ants and aphids?
Ants farm aphids for the sweet sap or honeydew aphids excrete. Ants will move aphids to new plants and will also protect them from predators. There is a study that showed aphids would not survive as well in many scenarios were it not for ants.
It is not only ahids ants protect, farm and spread. Mealy bugs and scale insects are also on the list and so when I see ants crawling between my plants, I know its bad news. Ants will also make strategic nests in pots, taking the potting mix out to make space for themselves and deprive the plant of nutrients. This further weakens the plants.
Which succulents are most susceptible to aphids?
Echeveria species (especially in the flowering season)
Although aphids can attack any succulent and I’ve seen them on almost every species of succulent over the years, they definitely have favourites.
Aphids usually appear when a certain plant is growing lots of new leaves as they like to feed on tender growth. Aphids also very much like flowers and when succulents are in bloom it is almost certain aphids will come out of the woodwork. This would usually be around autumn/winter (in moderate climates)/spring.
What causes aphids on succulents?
Change in seasons
Aphids are quite seasonal, though much will depend on where in the world you are. For most of the world aphids will come out in Spring, after the worst of the cold is over and then linger into summer.
Once it starts getting hot, aphids tend to disappear. In moderate climates without frosts or snow Aphids usually also appear at the end of Autumn and annoy the living daylight out of succulent enthusiasts and gardeners until the end of Spring.
As mentioned earlier, ants spread aphids and they can carry them quite a distance. Ants will find the most favourite succulents and will keep spreading aphids to the surrounding plants.
Succulent flowers are highly desirable to aphids and will attract them from afar. It is pretty much inevitable aphids will try and infest succulent flowers no matter how much you try and repel them. The best way is to anticipate aphids on succulent flowers and get rid of them as they start appearing. Multiple treatments may be necessary. At the nursery, we usually just cut the flowers off once aphids start attacking them.
How do I get rid of aphids naturally?
Aphids repelling plants
Pyrethrum based pesticides (organic)
Squashing aphids is the most effective and environmentally friendly way of control. I keep lots of long skewers with sharp pointy ends around the nursery and when I see aphids, I squash! This is, however, only feasible if there are only a few aphids on a succulent. In a full-blown infestation, it would take hours to get rid of every single aphid this way.
If you have a greenhouse, predatory bugs are a fantastic way of keeping aphids at bay. There is quite a range that can be purchased but the most popular are ladybug larvae, predatory wasps and hoverfly. These will work even in the garden, but there is always a chance they will just fly off.
Predatory bugs can also be attracted to the garden by growing specific flowering plants like lavender, herbs in flower, queen anne's lace or pyrethrum plants.
Growing flowering plants around succulents has other benefits as well. Some, such as lavender, herb flowers or marigold have a strong scent that can mask the scent of succulents and can confuse aphids. Although this is not a 100% solution and aphids usually find a way, it can reduce their numbers. Plus, flowers also look lovely.
Pyrethrum based pesticides are the most effective aphid killers I have come across. Organic pyrethrum sprays can be bought or synthetic ones are usually available in garden centres.
While the synthetic ones would have additives that are not organic, pyrethrum based sprays are low toxic and completely break down fast. They can kill beneficial insects, so we only use them in a full-blown infestations as we have quite a healthy population of aphid munchers around.
To prevent any unwanted deaths, I isolate the infested plants and spray after dark as most good insects do not fly in the dark. Spraying in the dark will also prevent burn marks caused by the sun (it is never a good idea to apply any pesticide in the middle of the day when the sun shines the strongest).
There are many natural pesticides that promise to kill a wide range of pests, but in my experience, they are not awfully effective. They can work on very mild infestations and the youngest of aphids, but even then they may not get every single one of the beasties.
Aphids come periodically and there is nothing you can do to completely prevent them. They are tiny and will get into greenhouses and even indoors. The only thing that can be done is to learn to live with them and try multiple solutions to keep them at bay.
Does vinegar kill aphids on succulents?
Vinegar can knock down young aphids but it is not a 100% solution. In our experiments not all aphids would die and heavy infestations would be unaffected.
Does diatomaceous earth kill aphids?
Diatomaceous Earth promises to kill a wide range of pests including aphids and ants. It is meant to cut their bodies. We’ve tried Diatomaceous Earth on many pests including aphids and the verdict is quite bleak- for us, this did not work and aphids survived.
What is the quickest way to get rid of aphids on succulents?
By far the quickest way to kill aphids on succulents is by using pyrethrum-based pesticide. Organic or synthetic versions can be purchased, and they kill ants as well. If there are only a couple of aphids, squashing is a fast and effective method too, though it may need to be repeated throughout aphid months.
It is important to get the dosage right as some succulents can suffer burn marks.
In conclusion, if you grow succulents, it is very likely aphids will pay you a visit one day. Wherever possible, try and use organic methods so good insects are not killed as well and spray in the evening. Although aphids sound like a horrible pest, they are unlikely to kill a healthy succulent and if left without treatment, they will disappear on their own (but can cause cosmetic marks.