Care should be taken when using coffee grounds as an alternative fertilizer. Some plants do not tolerate the home remedy, others love the collected powder. This guide reveals which indoor, fruit, vegetable and ornamental plants thrive even better with the help of coffee grounds.

Better growth thanks to coffee grounds

Since fertilizing with collected coffee powder changes the pH value of the soil, all plants that prefer an acidic environment benefit from the home remedy. Superficially, these are bog plants. But not only the optimization of the soil conditions speaks for using coffee for fertilization. Many vegetable and fruit plants are very sensitive. Only well-drained soil enables healthy growth. Coffee grounds attract earthworms, which loosen the soil in a completely natural way and thus create the best conditions.

In summary, the effects of coffee grounds on the vigor of a plant, provided it thrives in acidic soil, are as follows:

  • stimulates growth
  • strengthens the structure of the cell walls and thus the defenses of the plant
  • prevents the yellowing and drying out of the leaves
  • promotes water transport in the leaf veins
  • regulates the opening and closing of the stomata
  • accelerates plant metabolism (more energy thanks to photosynthesis)

From vegetable plants to indoor plants, it doesn’t matter whether a plant grows in a bucket or outdoors. The following is an overview of plants that benefit from coffee grounds fertilization:

vegetable plants

Cucumbers (Cucumis sativus)

  • optimal pH: 5.5 to 7.5
  • Timing of fertilizer application: regularly, increased during the growing season
  • other fertilizers: stable manure, nettle manure, rock flour

Cucumbers enjoy nutrient-rich and moist soil. At the same time, they need sun, which, however, allows the substrate to dry out quickly. The clever gardener covers the soil with mulch and works in the coffee fertilizer at the same time. It thus combines two care measures in one.

Pumpkins (Cucurbita)

  • optimal pH: 5.5 to 7.5
  • Time of fertilizer application: once a week
  • other fertilizers: nitrogen-rich complete fertilizer in the irrigation water, compost

Pumpkins do well in a sunny spot. In addition to sufficient light, nutrients such as potassium, phosphorus and nitrogen are also important. Old coffee powder provides these nutrients, which also enables environmentally friendly fertilization if the gardener mixes it with home-made compost.

Tomaten (Solanum lycopersicum)

  • optimal pH value: 6
  • Time of fertilizer application: regularly
  • other fertilizers: liquid fertilizer, compost and many more

As a heavy feeder, the tomato has a very high nutrient requirement, regardless of whether it is grown in a bucket or outdoors. Coffee grounds incorporated into mulch support the already important fertilization for the plant.

Zucchini (Cucurbita pepo)

  • optimal pH: 6 to 7.5
  • Timing of fertilizer application: regularly from June to August
  • other fertilizers: tomato or cucumber fertilizer, horn shavings, rock flour, nettle manure

The combination of mulch and old coffee powder is also ideal for zucchini, but is not absolutely necessary. The alternative fertilizer can also be administered in other ways, for example in the irrigation water.

fruit plants

Grumbling Bears (Rubus sect. Rubus)

  • optimal pH value: 5
  • When to apply fertilizer: in the spring, if necessary when the berries are ripening
  • other fertilizers: horse manure, cow manure, blue grain (sparing dosage)

In order for berries to form their tasty, deep blue fruits, they primarily need potassium, which is found in abundance in coffee. Without fertilizer, self-sufficient people unfortunately have to do without enjoyment.

Blueberries (Vaccinium myrtillus)

  • optimal pH: 4 to 5
  • Timing of fertilizer application: in spring and during fruit ripening in June
  • other fertilizers: low-lime fertilizer (e.g. for rhododendrons or azaleas)

In addition to sandy soil and a location in full sun, the blueberry also needs a lot of nutrients. Gardeners can cover their high demands with a coffee fertilizer.

Currants (Ribes)

  • optimal pH: 5.5 to 6
  • Timing of fertilizer application: in March before sprouting, again from April to May, before the onset of winter in autumn
  • other fertilizers: compost, manure, special berry fertilizer

The currant , on the other hand, proves to be easy to care for and undemanding . Nevertheless, the fruit plants are happy about moist, humus-rich soil with a high nutrient content. Since it is a shallow root, it is advisable to incorporate the coffee grounds in a layer of mulch that protects the roots from the sun.

ornamental plants

Dogwood (Cornus)

  • optimal pH: 5.5 to 7
  • Time of fertilizer application: autumn
  • other fertilizers: compost

The dogwood is one of the bog plants already mentioned. However, it is important to differentiate between these ornamental plants. Only varieties that love moisture need a lot of nutrients. Cornus species that prefer dry locations can also cope with poor soil.

Hydrangea (Hydrangea)

  • optimal pH: 5 to 6
  • Timing of fertilizer application: from spring to the end of August
  • other fertilizers: nitrogenous complete fertilizer with low phosphorus content

The hydrangea is another bog plant with high nutritional requirements. With a different dosage of coffee grounds, the gardener can vary the flower color.


  • optimal pH: 5.5 to 6.8
  • Timing of fertilizer application: March to April (compost) and October to November
  • other fertilizers: compost, horn shavings, horse manure, blue grain, liquid fertilizer

Magnolias are also typical bog plants. Here the gardener should sprinkle the coffee fertilizer superficially on the root disc, but not work it too deep into the soil.

Rhododendron (Rhododendron)

  • optimal pH: 4.5 to 5
  • Timing of fertilizer application: regularly from April to October
  • other fertilizers: special rhododendron fertilizer

Depending on the species, the bog plant rhododendron can reach the size of a shrub, needs a lot of water and sufficient nutrients for growth. It is best for the gardener to mix the coffee powder with horn meal and work it flat into the ground.

Tip: The right fertilizer can even compensate for less than ideal site conditions for a rhododendron.

indoor plants

Angel Trumpets (Brugmansia)

  • optimal pH: 6 to 7.5
  • Time of fertilizer application: regularly
  • other fertilizers: water-soluble complete fertilizer with a high potassium, nitrogen and phosphorus content

To form their impressive flowers, these houseplants need a lot of water and nutrients. Therefore, the combination of a mulch layer and coffee grounds is also ideal here. Firstly, the substrate does not dry out in this way, secondly, the coffee provides additional nutrients.

Note: The angel’s trumpet is very susceptible to snail infestation. However, the pests shy away from coffee.

Geranien (Pelargonium)

  • optimal pH: 5.5 to 6
  • Timing of fertilizer application: regularly (weekly or bi-weekly)
  • other fertilizers: liquid fertilizer

Geraniums delight every gardener with their variety of colors. However, the colorful flowers only form with a sufficient supply of nutrients. Coffee grounds as a home remedy has a supportive effect on this plant.

frequently asked Questions

Since coffee powder shifts the pH value of the soil to an acidic environment, lime-loving plants are very sensitive to the fertilizer. These include, for example, the blue cushion (Aubrieta), asters (Aster), lavender (Lavendula), sharps (Achillea), African lilies (Agapanthus), spurge (Euphorbia) as well as leeks (Allium porrum) and asparagus (Asparagus officinalis).

The recycling of an actual waste product alone makes old coffee powder a worthwhile, inexpensive alternative to purchased products. Coffee grounds are in no way inferior to these in terms of nutrient density. It contains large amounts of phosphorus, nitrogen, sulfur and potassium.

The powder can be incorporated in different ways. In addition to the possibility of dissolving the home remedy in the irrigation water, self-supporters can also mix it with organic material. It is only important that the powder is well dried when administered pure. Otherwise there is a risk of mold. However, if the gardener only applies it to the substrate surface, there is no benefit.

Overdosing on coffee is hardly possible. However, the powder is not a substitute for regular fertilization. It is only suitable as a supporting household remedy. Outdoor plants are fertilized every three months, while indoor plants are only fed once in winter and in spring before the start of the growth phase.

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