Be it a filter coffee, an espresso or a creamy macchiato, many of us start the day with the popular drink. But have you ever asked yourself whether coffee can also give your plants the energy boost they need? The idea of using coffee as fertilizer isn't exactly new. Many gardeners add coffee grounds to compost piles, where they decompose and mix with other organic matter to create fantastic, nutrient-rich soil. However, you usually use the coffee grounds for this, and not the coffee residue left in the cup. So can you water plants with coffee at home or in the office?
Watering plants with coffee: This speaks for itself
Depending on the type and preparation, coffee has a pH value between 5.2 and 6.9. The lower the pH, the more acidic it is, meaning coffee is quite acidic. Most plants grow best at a slightly acidic to neutral pH (5.8 to 7). Tap water is slightly alkaline and has a pH of over 7. Thus, using diluted coffee for plants can increase the acidity of the soil and contribute to optimal growth.
Use coffee or coffee grounds as fertilizer?
There is no clear answer to the question of which is better, because it depends. Coffee grounds, for example, contain nitrogen, which is an important component for plant growth. When it is composted, microorganisms are used that break down and release nitrogen. At the same time, the temperature of the compost heap increases and various pathogens and weeds are killed. This indirectly makes coffee grounds a good natural fertilizer for garden plants that love acidic soil. You can also collect and dry the powder and then sprinkle it directly into the root area of acid-loving plants.
Brewed coffee, on the other hand, is rich in magnesium and potassium, which also play an important role in plant growth. So it makes perfect sense to give the leftover coffee to your plants, right?
Which plants water with coffee?
If you are wondering whether you should use coffee grounds or brewed coffee on your plants, the first thing to clarify is whether you are dealing with garden or houseplants. Coffee grounds are not a suitable fertilizer for houseplants because they cannot be broken down into the potting soil and lead to mold growth over time. You should only use the coffee grounds outdoors.
To give houseplants a free, organic fertilizer, cold coffee from a pot is better. It is an excellent fertilizer for many types of houseplants, but can also be used outdoors. Diluted coffee adds just enough organic fertilizer to promote bushier, healthier plants.
Basically, plants that prefer acidic soil (such as African violets, Phalaenopsis orchids and Dieffenbachia) seem to respond well to weekly watering with coffee. Outdoors, acid-loving plants such as azaleas, rhododendrons, irises, lupins and any pine trees or shrubs do well when watered intermittently with cold coffee. Liquid coffee can also be used to irrigate a compost pile that has become too dry.
You should pay attention to this
An important point to note is that the coffee left in the cup is not always pure coffee. Most of us add sugar, cream, milk, flavorings or even a mixture of these to the popular drink. And while sugar in principle shouldn't be a problem for plants, the same cannot be said for milk and similar products. A plant that has been watered with sweetened or flavored coffee may soon be overrun by fungus gnats or scented ants. So make sure you only use black coffee and dilute it before watering the plants.
If you decide to water houseplants with coffee, be sure to keep a close eye on your plant. If the foliage begins to yellow or the tips of the leaves turn brown, it is a sign that the coffee is adding too much acid to the soil. In this case, you should stop watering with coffee and repot the plant if necessary.
So don't water your plants every time with the diluted coffee, because there is a risk that the soil will become too acidic and the plants will die. Once a week should be enough.
Also interesting:Are coffee grounds a good fertilizer for orchids?
Frequently asked questions
Can you water plants with leftover coffee?
In any case! Black coffee left in the pot can be poured over indoor and outdoor plants. Coffee residue is a source of nitrogen and fertilizes the plants. However, do not put coffee with added cream or sugar on the plants as this can harm them and also attracts ants and other insects.
How often can youWatering plants with coffee?
You should only water plants with coffee once a week. Store the leftover coffee in a container to use weekly and do not forget to dilute it with water in a ratio of 1:5 (one part black coffee, five parts water) before watering.
Are coffee grounds a good fertilizer?
Coffee grounds work well as fertilizerfor some plantsand their soil. Simply sprinkle the coffee grounds onto the soil around the plants. Some acid-loving plants like azaleas and blueberries love coffee grounds, but not all, because other plants like tomatoes don't tolerate them as well.
Can I use decaffeinated coffee?
Yes, decaffeinated coffee works just as well as regular coffee.
Can I use instant coffee?
Yes, you can use instant coffee, but it is not as effective as brewed coffee.
Do I have to brew the coffee?
You need to brew the coffee to extract the nutrients from the coffee beans.
Which houseplants like coffee as fertilizer?
You can use the diluted coffee fertilizer, for example, for birch figs, rubber trees, spider plants, ferns, monstera, arched hemp, single leaf, ivy, dieffenbachia and violin fig.
