Coffee Grounds As Fertilizer

Did you know used or fresh coffee grounds sometimes make an excellent plant fertilizer?

It’s true, but there are some caveats. Read on …


By their very nature, coffee grounds are acidic (high in acid). Fresh, unused coffee grounds are higher in acid than used grounds …

And since most plants like soil conditions that are neutral pH (neither high in acid or low in acid), how do coffee grounds fit into your arsenal?

Turns out, there are a few dozen plants that prefer a little more acidic soil …

Pink Azaleas by

Pink Azaleas

Most of these plants are fairly common in Zone 5 & 6 gardens – here are ten:

1). Azaleas

2). Blueberry

3). Carrots

4). Cucumbers

5). Garlic

6). Hydrangeas

7). Marigolds

8). Peppers

9). Spinach

10). Tomatoes


Coffee Grounds as FertilizerThe first thing to remember is used coffee grounds are less acidic than fresh. Therefore, when in doubt, start first with used grounds and monitor to see how your plants react …

Second, it’s always good to follow the old adage “less is more”. Start with a thin layer of grounds around your plants … a layer 1/2 inch thick is plenty for starters …

Use fresh coffee grounds around plants tolerant of higher acidity levels (like the list of ten above) …

The benefit of coffee grounds is simple. They add nutrients to the soil which in turn benefits your plants. Think of coffee grounds like a fertilizer – they add a jolt of growing power when applied and over time decompose to a neutral pH in time for a further application (at intervals of roughly 6-8 weeks).


With the list of ten plants above that do well in acidic soil, it’s perfectly ok to use fresh coffee grounds. For other plants, we recommend used grounds …

Of course, it’s always a good idea to research your specific plants – if care instructions specifically state the plant won’t do well in any level of acidic soil, it’s best to avoid using coffee grounds …

That said, used grounds are always the safest when applied in moderation. Almost any plant will benefit from a thin layer of used coffee grounds as a fertilizer …


The benefits of coffee grounds extend beyond fertilizer. Did you know slugs absolutely hate coffee grounds?

Ugh a Slug by

           Ugh … a Slug!

We didn’t know it either, but coffee grounds are slightly “rough” in texture. This texture is unappealing for slugs, as it scratches and chafes their body underside.

If you’ve got a slug problem, coffee grounds are an inexpensive and natural solution!

Just as slugs aren’t fond of coffee grounds, neither are cats or rabbits. If you’ve got a neighborhood cat who likes using your garden as a litter box, sprinkle coffee grounds around their “favorite” areas and you should rid yourself of the problem …

Finally, mix coffee grounds with water and steep like a tea. A good rule of thumb is about a five-to-one mixture of water to grounds in a spray bottle. The mixture is very effective in eliminating insects and other pests hanging out on your plants!

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