Many people start their day with a cup of freshly brewed coffee, and after this daily ritual there is always a cake that can simply be thrown into the bin or used coffee grounds as fertilizer for houseplants, flowers and gardens.
The answer to the question of whether coffee grounds can be used as fertilizer is obvious: of course, you can! But let’s take a closer look at what benefits this brings to plants.
- When coffee grounds are added to the soil, especially clay and loamy soil, its structure becomes looser, drainage capacity and air exchange improve. In addition, coffee attracts earthworms, which also contribute to loosening the soil.
- The smell of coffee can repel harmful insects. He doesn’t like cats either. If you sprinkle your garden beds with coffee grounds, you don’t have to worry that uninvited visits from your pet will damage tender plantings.
- It is believed that fresh coffee has an increased level of acidity, and top dressing with such characteristics is not suitable for every plant. However, to avoid acidification of the soil, it is enough to shed thick water and then apply in the garden or vegetable garden.
- Coffee grounds as a fertilizer are rich in minerals and trace elements. Potassium and phosphorus contribute to good flowering and abundant fruiting. Nitrogen activates the rapid growth of plants. Copper helps to resist a number of diseases. And although the total amount of useful substances in coffee cake is about 2–3%, which means that it can hardly be considered a full-fledged fertilizer, the use of grounds as an organic plant food is fully justified.
For which plants is coffee top dressing suitable?
And yet, sleeping coffee is a top dressing that is not suitable for every plant. Therefore, before you widely use it in your garden, you need to study for which plants it is most effective to use coffee grounds as a fertilizer. It is most useful for flowers that prefer a low pH level – azaleas, hydrangeas, heathers and rhododendrons. Due to the large amount of potassium in the composition, coffee grounds can be used as a fertilizer when growing vegetable crops such as tomatoes, potatoes, cucumbers, and peppers. Feeding fruit trees with sleeping coffee will also help to significantly increase their fruiting. Magnesium, which is part of coffee, is useful for berry bushes. Magnesium and potassium will help to get a high yield of root crops, while nitrogen is indispensable for green crops.
From domestic plants, roses, palm trees, ficuses and ferns, as well as violets and asparagus, respond best to coffee dressing. When using coffee grounds as a fertilizer for houseplants, it is recommended to shed and dry it first. If you simply pour the rest of the coffee from the cup into the pot, most likely there will be no benefit, but on the contrary, the soil may become covered with a crust and begin to mold. To prevent this, you need to mix the prepared thick with soil suitable for this type of plant.
Coffee with sugar or milk should not be used for fertilizing horticultural, garden and flower crops, since sugar attracts ants, and milk provokes the development of putrefactive processes in the soil, which can harm the root system of plants.
Before using used coffee as a fertilizer when watering plants, it must be diluted in a sufficient amount of liquid. To prepare a solution for 10 liters of water, 1 cup of grounds is required. Cake is poured with a small amount of water and left to swell for about a day. After swelling, the amount of liquid is adjusted to the calculated amount and used for watering plants.
After feeding the plants with coffee grounds, it is advisable to water the soil again, but with clean water. This technique will allow the minerals to be slowly released, nourishing the plants. When planting bushes, you should spill the ground with coffee solution at the rate of 1 liter under the bush.
Coffee grounds can also be used for mulching plantings in order to protect the soil from drying out, repel pests and improve soil structure. However, it must be remembered that when using the grounds as mulch, as in the case of using coffee cake as a fertilizer in the garden in the country, it should be thoroughly dried to prevent the development of mold.
Dormant ground coffee as a fertilizer can be added to the planting hole or hole before planting to improve soil structure. This technique makes the land more drained and looser, which ultimately has a positive effect on plant health and yield. When used on light soils, the thick acts as a binder. In this case, top dressing is applied to the upper soil layer at the rate of 200 ml per 1 m².
To accelerate the maturation of compost, it is enough to spill each layer no more than 10 cm thick with coffee infusion. Coffee grounds perform the function of nitrogen components that trigger an exothermic reaction inside the compost heap, in other words, heating it up, due to which the compost matures much faster. This method is so effective that some summer residents specifically purchase inexpensive varieties of ground coffee and sprinkle layers of compost on them.
Recently, the method of growing seedlings of vegetable crops on a coffee substrate has become popular. But in order to prevent depletion of the soil, it is necessary from time to time to feed the seedlings with complex fertilizers.
Coffee cake as a fertilizer in the garden is also very effective for protecting plants from sexually mature individuals of harmful insects – ants, snails, aphids, slugs. According to the experience of some gardeners, coffee can also destroy pest larvae, in particular mosquitoes and garden bugs. This remedy is not as effective as insecticides, but also much safer.
Where not to use coffee grounds
Coffee grounds are rich in nitrogen, so if used in excess, you can burn the root system, which will lead to the death of the plant.
Poorly dried coffee waste can cause mold and fungal diseases to develop and kill plants. In addition, coffee fertilizer is not suitable for tradescantia, asparagus, geraniums and other crops that prefer more alkaline soil. Top dressing from pomace can change the shade of rose flowers.
Dried coffee grounds are very light, so when used dry, the slightest breeze can blow them off the garden. To prevent this from happening, it is recommended to mix the cake with earth or sawdust and close it shallowly into the soil.
If after treatment with coffee grounds the color of the leaves of the plants has changed, the use of coffee grounds as a fertilizer should be discontinued. You can carefully strain the coffee infusion and use only liquid for irrigation, and use the thick, for example, to feed conifers.
It is recommended to prepare fertilizer from coffee grounds for giving, using cake from the preparation of only natural coffee. Instant powder and granulated coffee are not advisable to use for this purpose, since their nutritional value is not great.