What Plants Don’t Like Coffee Grounds

What Plants Don’t Like Coffee Grounds

Coffee grounds are often used as a natural fertiliser in the garden, but not all plants benefit from them. Understanding what plants don’t like coffee grounds can help you avoid damaging your flowers, vegetables, or shrubs.

Why Some Plants Dislike Coffee Grounds

Used coffee grounds are acidic and contain nitrogen, caffeine, and organic compounds. While some plants benefit from a little acidity, others do not. Too much can:

  • Alter the soil pH and make it more acidic

  • Inhibit seed and plant growth

  • Attract slugs and snails if left on the soil surface

  • Compact the soil — because coffee grounds can compact easily when wet

The impact on the pH level is one of the biggest reasons certain plants struggle when you apply coffee grounds routinely.

Plants That Don’t Like Coffee Grounds

Some plants are sensitive to acidity or chemicals in coffee grounds. Avoid adding coffee grounds to:

Lilies

Prefer neutral to slightly alkaline soil, so extra acidity can interfere with growth.

Ferns

Many fern varieties do not tolerate acidic conditions; coffee can scorch delicate fronds.

Succulents & Cacti

These plants thrive in well-draining, low-nutrient soil. Coffee grounds hold moisture and increase nutrients — the opposite of what these plants thrive on.

Hydrangeas (variety-dependent)

While some hydrangeas like acidity to intensify blue colouring, others react poorly to extra acid.

Vegetables Like Beans & Peas

Nitrogen-rich grounds can disrupt root development and plant growth in legumes.

Instead of risking these plants, use coffee grounds for acid loving plants like azaleas, rhododendrons, camellias, and blueberries — which naturally thrive in acidic soil.

How to Use Coffee Grounds Safely in the Garden

Even for plants that tolerate acidity, you should apply coffee grounds correctly:

1. Mix into Soil

Don’t leave grounds sitting on top of soil as they can compact and form a crust.
Mix them lightly with other organic matter to improve soil structure.

2. Compost Coffee Grounds

The safest approach is to compost coffee grounds with brown materials like leaves, cardboard, or mulch. This balances nutrients and prevents overly acidic soil.

3. Use in Moderation

A thin layer or small handful mixed into soil occasionally is enough. Overuse can harm more than it helps.

Alternative Uses for Coffee Grounds

If your plants don’t handle coffee well, there are still plenty of ways to put them to good use:

Fertiliser for Acid-Loving Plants

Perfect for azaleas, rhododendrons, camellias, and blueberries.

Composting

Helps balance the green and brown waste ratio in compost bins.

Pest Deterrent

Can help repel slugs and snails from certain plants.

Household Cleaning

The gritty texture lightly scrubs and deodorises surfaces.

If you want an excellent source of fresh grounds to recycle, try brewing with a flavourful blend such as House Blend Coffee or a bold option like Royal Blend Coffee — both produce grounds that compost beautifully.

Tips for Gardeners

  • Know your soil type — some plants prefer neutral or alkaline soils.

  • Observe plant reaction — remove coffee grounds if leaves yellow or growth slows.

  • Pair with compost or mulch — helps balance the nutrients.

  • Don’t overuse — moderation is key to avoiding harm.

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