We often associate the word “succulents” with cacti, but this category of plants includes a wide range of species from all over the world.
The term refers to any plant that stores water in its stem or leaves. Many types of succulent species tend to be sensitive to pesticides and may develop severe burns or other symptoms when treated.
Even neem oil, known for its effectiveness and compatibility with a wide range of plants, has its shrew of horror stories when used on succulents.
But does this mean neem oil is bad for your succulent plants?
Can You Use Neem Oil On Succulents
Neem oil is an organic pesticide made from vegetable oil from the pressed fruits and seeds of the Neem tree (Azadirachta indica).
It contains an active ingredient called azadirachtin, which repels and kills pests or bugs, including aphids, spider mites, whiteflies, Japanese beetles, and fungus gnats.
Neem oil works effectively as pest control, as it kills at every life cycle stage, including they are eggs, larvae (grubs), pupas, and adults.
Neem oil is also effective against fungal diseases and other problems like anthracnose, rust, black spot, and powdery mildew.
The good news is that you can actually safely use neem oil on most succulents.
By following some simple rules and paying attention to your plant’s reactions, Neem can become a succulent’s best friend.
Common Mistakes with Succulents
Most horror stories you’ll find online can be traced back to a few common mistakes.
Thankfully, these mistakes are easy to avoid once you’re aware of them.
Here are some of the most frequently reported ones:
- NEVER use a commercial pre-mixed neem spray on succulents. Neem oil begins degrading as soon as it’s mixed with water, so the product is likely heavily degraded by the time you receive it. Additionally, you have no control over the contents of sprays you didn’t make yourself.
- NEVER spray plants in full sun or direct sunlight. Not only does Neem oil break down when exposed to UV rays, but most succulents will also suffer severe leaf burns if the leaves get wet while exposed to the midday sun.
- ALWAYS test before making a full application. This cannot be stressed enough, especially on succulents. Apply a small amount of your neem spray to a single leaf or piece of stem and wait 24 hours to see if there’s a negative reaction – never the entire plant. Any signs of distress mean the plant has an allergy or oversensitivity to Neem, and you should use a different method.
- NEVER use raw neem oil as a foliar spray on sensitive plants. Azadirachtin can cause severe burns and do far more harm than good. Instead, only use clarified Neem for sprays and reserve raw Neem for soil soaks.
- NEVER mix Neem with other solutions, such as isopropyl alcohol. Not only can this cause a reaction in some cases, but many of the suggestions you’ll find online are harmful to your plants. Insecticidal soap is the only safe additive for neem oil when used as the emulsifying agent.
Neem Foliar Spray
The most common form of neem treatment, Neem foliar sprays, use clarified hydrophobic neem oil.
This form of Neem has most of the Azadirachtin removed, with only between .5 and 3% percent Azadirachtin remaining.
Always aim for 1% percent or lower when dealing with sensitive plants unless the infestation doesn’t show signs of decrease after two weeks of use.
Emulsify 1 quart of water by adding 1 teaspoon of liquid Dawn dish soap, insecticidal soap, or pure castile soap and gently mixing.
Next, add 1 teaspoon of clarified Neem to the liquid soap and blend thoroughly.
Pour the mix into a spray bottle and thoroughly spray your plants.
Be sure to get the undersides of leaves and any crevasses or joints, but avoid spraying the flowers or exposed roots.
Repeat the treatment every other day for 14 days or until the infestation is gone.
It would be best if you only sprayed at dusk or dawn to avoid harming beneficial insects and minimize the risk of sunburn.
The Neem will dissipate in 45 minutes to 1 hour without leaving residue behind.
Note that you can use neem foliar sprays every two weeks as a preventative.
Special Fungicidal Recipe
This recipe will require you to test each ingredient separately for potential reactions but will work on many succulents to control external fungal infections.
Remove dead leaves and prune away any visibly infected leaves if the infection hasn’t spread too far, but you may need to leave them if the disease has spread too far.
Emulsify one gallon of water using 1 teaspoon of the soaps mentioned.
Next, add 1 teaspoon of rosemary and peppermint oils and two tablespoons of clarified Neem and olive or almond oils.
Thoroughly treat the plant, including healthy leaves.
Repeat this process every 7 days until the infection is eliminated.
You may continue using treatments monthly as a preventative.
More on Using Neem Oil as a Fungicide
Neem Soil Soak
This is where 100% percent cold-pressed raw neem oil comes in handy.
The effects on infestations are slower than a foliar spray but work just as well and kill subterranean pests, bacteria, and invasive fungal infections.
Create an emulsion using 1 teaspoon of soap per gallon of water and mix in 2 tablespoons of raw Neem.
Pour 2 to 3 cups of the mixture around your plant’s roots, being careful not to splash the stem or visible roots.
This treatment remains active for up to 22 days and should be repeated every three weeks until the infestation is gone.
It can also be applied every three weeks as a preventative.
Read more on Using Neem as a Soil Drench or Soak
Neem Cakes
The solid byproduct of extracting neem oil, neem cakes still contain trace amounts of raw neem oil.
The cakes are rich in organic matter, micronutrients, and fatty acids, bearing an average NPK of 4-1-2.
These cakes make an excellent fertilizer for succulents that require a similar NPK ratio.
The presence of trace neem also means they’ll attack nematodes, and grubs and can help treat soil-based infections such as root rot. Details on Neem for Root Rot.
Learn more about Neem Cakes And How They Are Used.
Due to the low neem oil content, neem cakes are sometimes less harmful to sensitive plants, although they carry the same burn risks as any fertilizer when not correctly mixed into the soil.