Your daily cup of coffee contains high levels of nitrogen, which promotes the growth of plants that prefer more acidic soils, as well as significant amounts of magnesium and potassium, which are crucial for their growth and health. However, excessive coffee consumption is not only harmful to humans, but also to your crops. That's why in this article we will clarify the following questions: Watering plants with coffee - which ones are suitable for this, how do you do it correctly and does the caffeinated drink help against fungus gnats on potted plants and snails in the garden!
As you know, the idea of using coffee grounds as fertilizer is not new. Many gardeners add it to the compost pile, where it decomposes and mixes with other organic matter, creating fantastic, nutrient-rich soil. Of course, this doesn't happen with the cold cup of coffee on your desk. So, how can watering plants with brewed coffee benefit them and what should you consider to achieve optimal benefits.
Since coffee grounds are full of beneficial substances for your plants, it makes sense that brewed coffee also contains plenty of them. Of course, you cannot water your plants with coffee that has added cream, milk, sugar or sweetener. You must use pure coffee diluted with water.
What is the correct dilution ratio
To use coffee as a plant fertilizer, you must dilute it. It should resemble weak tea. Leave your mixture at a ratio of 1 part coffee to 3 parts water, an equal parts dilution between coffee and water is also suitable. When diluting, also consider how strong you are making your caffeinated drink. If you make him stronger, use the first 1:3 option, if he is weaker, use the second.
Watering plants with coffee – Is there potential damage?
As a rule of thumb, you should only use diluted coffee as a water replacement once a week. Remember that overdoing it can lead to negative results. A sign of this is if you notice the leaves of your plants turning yellow or brown. This means that the soil has become too acidic. In this case, you should stop watering the coffee and possibly repot the plant.
Which plants react well to coffee?
For those of you who are new to gardening, we will explain the basic principles. Some plants like acidic soil and others like alkaline soil. Coffee and coffee grounds are very acidic. So when you add them to the soil, it becomes acidic. This would be a problem for the plants that like an alkaline environment. Let's look at the same statement but with the numerical values.
Coffee has a pH value of 5.2 to 6.9, depending on the variety and how it is prepared. The lower the pH value, the more acidic the coffee is. Adding it to the soil will lower the pH of the soil and this can be a big problem for plants that prefer a higher pH.
Most plants grow best at a slightly acidic to neutral pH (5.8-7). Tap water is slightly alkaline and has a pH of over 7. Mixing it with coffee will lower the acidity accordingly, so your plants won't be at risk of nitrogen overdose. Here's which plants love coffee!
How can you measure the pH of the soil yourself and check the nutrient content of the plants?Find out here!
These vegetables love acidic soil with a low pH (5.5 to 7.5)
Here is a list of vegetables that would appreciate a sip from your leftover coffee:
- Cucumbersgrow best in acidic to neutral soil with a pH of 5.5 to 7.0. They germinate in about seven days at a temperature of 18-20 degrees Celsius. They love moist (but not soggy) soil and full sun. Cucumbers are a good option for vertical gardening when soil space is limited.
When are cucumbers ready to harvest? You can do thatfind out here!
- Carrotsgrow best in acidic to neutral soil with a pH of 5.5 to 7.0. It takes 2 to 3 weeks for the seeds to germinate at a temperature of 10 and 25 degrees Celsius. They like smooth, sandy soil that is moist (but not waterlogged).
- Tomatoesgrow best in acidic to slightly alkaline soil with a pH of 5.5 to 7.5. Your seeds take 6 to 11 days to germinate in ideal conditions: moist (but not soggy) soil at 24 to 28 degrees Celsius. Tomatoes prefer full sun. They are also a good option for vertical growing if you have stakes to support them as they grow larger.
How coffee grounds stimulate fruit formation and the ripening period of tomatoes?You can find out here!
Coffee for plants –Other vegetables that may benefit:
- Zucchini
- Beans
- Saddlery
- pumpkin
- Kohlrabi
- Melon
- Leek
- Broccoli
- Peas
- Paprika
- Carrots
- Brussels sprouts
- Spinach
- asparagus
- Beetroot
- Kale
- radish
Acid-loving fruit trees and shrubs
- Blueberries: These acid-friendly fruits like soils with a pH between 4.5 and 5.5. They are also beautiful to look at and delicious to taste.
- Blueberriesare packed with vitamins. They grow in similar conditions to blueberries.
- currants: These respond well to a slightly acidic soil with a pH of 6 to 6.5. They also prefer full sun, but also grow in partial shade. They like well-drained, nutrient-rich soil.
Water plants with coffee – these also benefit from soil with a pH value between 5.5 and 7.0:
- Apples
- Pears
- Figs
- Peaches
- Nectarine
- Pomegranate bug
Water plants with coffee – these flowers like it!
Watering flowers with coffee – These are perfect for this:
- lily of the valley: A shade-loving flower that grows in soil with a pH between 5 and 6.5.
- Camelie: This beautiful romantic flower, which blooms in gorgeous shades of pink and red, is often considered difficult to grow. However, this is usually because the soil is too alkaline. Camellias prefer acidic soil with a pH of 5.5 to 6.5 and are perfect shade plants.
- Cyclamen: This attractive plant prefers medium acidity (5.5 to 6.5) and grows well in full or partial shade.
- Begonias: These annual or perennial flowers thrive in sandy loam soil that is slightly acidic (pH between 6.0 and 6.5). Begonias are also an elegant houseplant.
- Daffodils: These well-known spring bloomers like slightly acidic to neutral soil. They are also easy-care flowers that do well in pots.
Ornamental plants that require more nitrogen
- Blue hydrangeas: For hydrangeas to bloom truly blue, they need acidic soil with a pH of 5.5 or less. Neutral or alkaline soil causes the flowers to turn pink.
- Rhododendron: These beauties thrive in acidic soil with a pH of 4.5 to 6.0.However, if you notice yellowing leaves, there could be a number of possible causes. What these are and what you can do about themfind out here!
- Magnolias:This magnificent flowering tree prefers soil with a pH of 5.0 to 6.0.
- Azaleas: The best soil for these attractive garden plants is one with a pH of 4.5 to 6.
- Watering plants with coffee – Gardenia: This elegant shrub is a tropical plant but makes an excellent houseplant. Since she likes acidic soil of 5.0 to 6.5, she will appreciate if you water her with diluted coffee once a week.
Tip: Use cold coffee against fungus gnats
Cold coffee against fungus gnats: Dilute cold coffee 1:1 with water and water your garden and houseplants occasionally (once every two weeks) with this mixture. The coffee will repel the pests as the caffeine in it is toxic to their larvae.
Coffee grounds against fungus gnats: Sprinkle it on the soil around the infected plants, as this thin layer prevents female fungus gnats from laying eggs.
Coffee grounds against snails
Fill a bottle with lukewarm water and add a few spoonfuls of coffee powder. Spray affected plants with the solution to quickly and effectively get rid of slugs. The procedure will not harm the plants.
For more useful information on how to use coffee to fight a snail infestation,can be found here!
