What Plants Tolerate Coffee Grounds?

Last updated on October 23rd, 2023 at 08:59 pm

You’ve heard that coffee grounds can be used as fertilizer and now you’re wondering which plants tolerate coffee grounds?

Here you can find the most popular plants – flowers, vegetables, fruits, herbs and ornamental shrubs – that like coffee grounds.

All plants that prefer a rather acidic soil (pH less than 7.0) can be fertilized with coffee grounds. These include, for example, well-known flowers such as geraniums or orchids. Vegetables, such as cucumbers or peppers, or herbs, such as parsley or peppermint, also tolerate coffee grounds. Fruit varieties such as blueberries or currants and also well-known ornamental shrubs such as hydrangeas or rhododendrons like acidic soils and therefore also coffee grounds.

Which plants tolerate coffee grounds?

Due to the tannic acid in coffee grounds, they are (slightly) acidic. Depending on the variety, degree of roasting or brewing temperature, the acidity can sometimes vary somewhat.

This means that coffee grounds are best suited for plants that need or prefer a (slightly) acidic soil.

An acidic soil has the characteristic of having a low pH, i.e. below 7 or 6. A pH around 7 is neutral and above that is alkaline or basic.

However, coffee grounds can also be used to lower the pH value of the soil, i.e. to neutralize it more quickly, for example, if the pH value is high.

List of plants that tolerate coffee grounds

Below I have listed all the flowers, vegetables, herbs, fruits and ornamental shrubs that require (slightly) acidic soils and for which you can therefore use coffee grounds as fertilizer without any problems:

Use coffee grounds as fertilizer for flowers

Many flowers tolerate coffee grounds as fertilizer very well, or even need a (slightly) acidic soil to survive.

These included very prominent species such as heathers, geraniums and even peonies.

• Anemones
• Begonias
• Angel’s trumpet
• Erica
• Geraniums
• Lilies
• Lupines
• Lily of the valley
• Daffodils
• Orchids
• Peonies
• Phlox
• Delphinium
• Roses
• Pansies

Coffee grounds as fertilizer for orchids

Coffee grounds can be used as fertilizer for orchids without any problems because orchids prefer a pH value of 5.0-6.5, which is in the slightly acidic range.

Since orchids are very demanding plants, you should be very careful with the amount of coffee grounds and the frequency of fertilizing at first.

As described in this article, you should not fertilize with coffee grounds more than 4 times per year.

Also, I would recommend fertilizing orchids only indirectly with coffee grounds, that is, soak the orchid roots in coffee grounds water to avoid permanently mixing the orchid substrate with coffee grounds.

Coffee grounds as fertilizer for roses

Coffee grounds are a good fertilizer for roses because roses are heavy feeders, so they need a lot of nutrients, and prefer a slightly acidic pH of about 5.5-6.5.

Roses can be fertilized either directly, with pure coffee grounds, or indirectly, with coffee grounds water. Both variants work very well and fertilize the roses to the same extent.

Use coffee grounds as fertilizer for vegetables

Many vegetables like coffee grounds as fertilizer because they prefer a neutral to slightly acidic soil. These are, for example, pumpkin, radish or radish.

• Cucumber
• Pumpkin
• Radish
• Radish
• Turnip
• Tomatoes

Coffee grounds as fertilizer for peppers
Coffee grounds as fertilizer for peppers is very suitable, bell pepper plants require a slightly acidic pH of 5.5-6.5.

Depending on which option you prefer, peppers can be fertilized either directly with coffee grounds or indirectly with coffee grounds water.

Coffee grounds as fertilizer for tomatoes
Tomatoes, like potatoes, are heavy growers and like a slightly acidic to neutral soil pH of about 5.5-7.5. Nevertheless, coffee grounds are also very suitable as a fertilizer for tomatoes, as they contain many important nutrients and thus enrich the soil.

Since the additional nutrients are more important to tomatoes than small fluctuations or deviations from the ideal pH, you can fertilize tomatoes with coffee grounds up to 4 times a year.

Coffee grounds as fertilizer for cucumbers
Cucumbers like a slightly acidic to neutral soil pH of 5.5-7.0, and so you can also fertilize cucumbers with coffee grounds at any time without any problems.

In what form, whether as a solid fertilizer or as a liquid fertilizer, cucumbers are fertilized with coffee grounds does not matter because both variants work equally well.

Use coffee grounds as fertilizer for herbs.

Many herbs prefer rather poor and even acidic soils, and thus can be fertilized with coffee grounds without any problems. These include heather, parsley, peppermint or sorrel.

• Arnica
• Bearberry
• Bearwort
• angelica
• Heather
• Perilla
• Parsley
• Peppermint
• Quender
• Rose root
• Sorrel
• Silver Lady’s Mantle
• Sundew

Use coffee grounds as fertilizer for fruit

Some types of fruit also tolerate coffee grounds as they prefer acidic soil or require a lot of nutrients.

These include, for example, blueberries, currants or rhubarb.

• Blackberry
• Blueberries
• Raspberry
• Currants
• Chestnut
• Cranberries
• Rhubarb
• Watermelon

Coffee grounds as fertilizer for strawberries

Strawberries prefer a neutral to slightly acidic soil. Therefore, you can use coffee grounds as fertilizer for strawberries very well, but should not overdo it with fertilizing.

That is to fertilize the strawberries especially in the growth phase in the spring up to 2 to 3 times and if necessary during the harvest phase again.

Use coffee grounds as fertilizer for ornamental shrubs

Some well-known ornamental shrubs also like coffee grounds or acidic soil. These include hydrangeas and rhododendrons as probably the best known representatives that like acidic soils.

• Azaleas
• Ferns
• Hydrangeas
• Some palms
• Rhododendrons

Coffee grounds as fertilizer for palms

Palm trees sometimes like strongly different soil pH values. Therefore, coffee grounds are suitable as fertilizer only for those palms that prefer a slightly acidic soil, which is the case, for example, with the hemp palm, honey palm, kentia palm, holly palm, golden fruit palm or coconut palm.

Coffee grounds should not be used as fertilizer for palms that prefer a more alkaline soil. These are, for example, the Christmas palm, date palm or the mountain palm.