What Plants Should You Not Use Neem Oil On?

Neem oil is a substance that has risen in popularity over the years as people search for more natural alternatives.

As gardeners, while we want to keep our plants happy and thriving, we also endeavour to use the least amount of chemicals in our garden.

For this reason, we search for more organic and natural substances to get rid of the pests in our gardens.

Neem oil is one such substance that has risen in popularity over the years as people search for more natural alternatives. It is used widely by gardeners as an organic pest control spray.

What is neem oil?

Neem oil is a natural substance that is extracted from the neem tree (Azadirachta indica). The oil is extracted from the seeds of the tree usually using a cold-press method. 

This oil has quite a strong aroma that’s somewhat similar to garlic. You might be interested to learn that this pungent oil is not only used for pest control but can also be found in a variety of cosmetics and beauty products.

Neem oil | Plant care

How does neem oil work to control pests?

The active ingredient in neem oil is azadirachtin. This ingredient works quite effectively at killing the insects. Primarily, because it’s an oil, it suffocates the insects by covering their bodies.

The pungent aroma of neem oil is also effective at repelling certain insects from your garden. 

Neem oil plant spray 1 | Plant care

This product can work very effectively on pests such as whiteflies, caterpillars, spider mites and beetles. In other words, insects that have soft bodies.

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What plants should you not use neem oil on?

While neem oil is a totally natural and organic product, care should still be taken to not spray it on very delicate plants. This product is most effective when used on plants that have larger leaves with a smooth surface.

Some plants that you should avoid spraying neem oil on include herbs such as basil, parsley, dill, thyme, coriander, caraway and oregano.

Italian Parsley harvest 1 3 | Plant care

Vegetables with delicate leaves such as lettuce, spinach, arugula or peas should also not be sprayed with neem as this can cause the leaves to burn.

It’s also wise not to use neem oil on plants that have just been repotted. Wait at least a couple of weeks until the plant has settled into its new environment.

You also want to avoid spraying neem oil on plants that are already stressed. In this case, it’s a good idea to do a small patch test by spraying a tiny amount on a leaf or two to ensure that no damage occurs.

Why should neem oil not be used on certain plants?

Even though neem oil is a natural product, when sprayed on plants with fairly delicate leaves, it can easily burn the foliage. This is especially the case if the plants are exposed to full sunlight.

That’s why it’s often recommended that you only treat your plants for pests and diseases on cloudy or overcast days.

Plus, it’s a good idea to only apply any type of pesticide or fungicide early in the morning or later on in the day when the heat of the sun has waned.

Are there any organic alternatives to neem oil?

While neem oil is a natural and organic product, it is important to follow good cultural practices when using it in the garden. Make sure you wear gloves and eye protection, and avoid getting it on your skin.

It’s also vital that you wash any produce that has been sprayed with neem oil before consumption.

washing vegetables | Plant care

While neem oil is highly effective at controlling unwanted pests in your garden, there are a few alternatives that can be just as effective.

White oil is one such product that has been used by gardeners right around the world for many, many years. But, the commercial product that you can buy is petroleum-based, so it’s actually better to make your own white oil using products that you’ll already have in your pantry.

Rosemary oil is another alternative that is gaining in popularity. The benefit of using this is that it has a far nicer aroma than neem oil. 

Other essential oils that can be used are peppermint oil and clove oil. When mixed with water and some dishwashing detergent, they work in a similar fashion to neem oil by suffocating soft-bodied insects.

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Annette Hird

Annette Hird is a gardening expert with many years of experience in a range of gardening related positions. She has an Associate Diploma of Applied Science in Horticulture and has worked in a variety of production nurseries, primarily as a propagator. She has also been responsible for a large homestead garden that included lawn care, fruit trees, roses and many other ornamental plants. More recently, Annette has concentrated on improving the garden landscape of the homes that she has lived in and focused a lot of energy on growing edible plants as well. She now enjoys sharing her experience and knowledge with others by writing articles about all facets of gardening and growing plants.


2 thoughts on “What Plants Should You Not Use Neem Oil On?”

    • You can use white oil or neem oil for this. Because these products are oil-based, they will cling to the pests and smother them.


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