Yes, they do. Coffee grounds work absolutely great for onions. Coffee grounds contain nitrogen which is an essential nutrient for onions. You can have the grounds sprinkled on top of the beds and water them in or allow the rainwater to sink them in.
With any of these, the nutrients present in the grounds should sink in. Onions are vegetables and it is known that generally, vegetables are like coffee grounds due to the fact that the grounds contain essential nutrients required by the vegetable plants thus, beneficial to them. Explained below are ways by which you can use coffee grounds for your onion plants.
1) Use Coffee Grounds as Fertilizer for onions
Coffee grounds contain essential nutrients such as nitrogen, potassium, phosphorus, as well as other micronutrients. This makes it an excellent source of fertilizer. You can have the grounds sprinkled thinly into the soil or you can add them to your compost heap.
Coffee grounds are regarded as “green material” or nitrogen-rich organic material so it is essential you balance them with the correct proportion of “brown material” or “carbon-rich materials” such as dried leaves, newspaper, or woody prunings. Your compost heap contains tiny munchers and gnawers which will help in processing and mixing them effectively. Using coffee grounds as fertilizer for your onion plants is absolutely safe and also beneficial for your plants.
Read also: Do Marigolds Like Coffee Grounds? Step By Step Answer
2) Use Coffee Grounds as a Natural pesticide in onions garden
Applying coffee grounds to your onion plants helps to keep away pests. This can be done by spreading the used grounds around the onion plants carefully without the grounds having direct contact with any part of the plant. Slugs that can be destructive tend to avoid plants having coffee grounds around them or applied to the soil.
The caffeine present in the grounds is harmful to the slugs thus, contributing to the reasons why they stay away from such plants having coffee grounds applied to them. The strong smell of the grounds also keeps away pests from your garden.
Read also: Do Sunflower Like Coffee Grounds? Step By Step Answer
3) Use Coffee Grounds as Mulch in onions garden
To use coffee grounds, it is essential to mix the grounds with other organic matter such as compost or leafmold before making use of it as a mulch. You can also rake your coffee grounds into the top layer of soil so they can’t clump together. This is an alternative method.
Coffee grounds could be detrimental in the sense that they contain very fine particles which are prone to locking together and this can turn them into a barrier that will resist water penetration thereby, resulting in the plants dying of thirst which is the more reason why the coffee grounds need to be mixed with other organic matter, compost being a good example, before using it as a mulch. Coffee grounds are also acidic and the acidic content helps in acidifying the soil thus lowering the pH of the soil.
Read also: Using Coffee Grounds And Eggshells For Tomato Plants – Step By Step Guide
Coffee grounds are beneficial to onion plants in many ways resulting in healthy growth and development of the plants coupled with a good yield. Thus, onions are lovers of coffee grounds.