Coffee grounds contain about 2% nitrogen with variable amounts of phosphorus and potassium which are essential nutrients for the growth of tomato plants. As the grounds decompose, there is a release of these nutrients into the soil thus, making them available to the plant.
The effect of coffee grounds on growth is yet to be scientifically proven. Even though they may give tomato plants a little boost of nutrients, in the long run, the concentration of the concerned nutrients might not have a visible effect on the plants when compared with that of organic fertilizers.
1) ACIDIFICATION OF THE SOIL
Coffee grounds are known to lower the pH of the soil. Hence, making it more acidic. Tomato plants are known to grow best in slightly acidic soil. This gives proof that coffee grounds can be beneficial to the health of tomato plants.
However, even though tomatoes are lovers of acidic soil, studies have shown that coffee grounds might not be the best option. The average pH of coffee grounds appears to be around 6.5.
This is not the same for all studies. Certain other gardening products can help in lowering the pH of your soil but it is important that all products must be used with proper care and caution while strictly adhering to the given instructions.
If you detect a soil problem, first of all, determine the cause by conducting a soil test. This is due to the fact that amending the soil pH unnecessarily can end up having a negative effect on your tomato plants.
2) FUNGAL DISEASES PREVENTION
Every tomato gardener detests fungal diseases and wishes to always avoid them. Fusarium wilt which is a serious fungal disease can totally destroy your tomato garden and bring it to an end as it has no cure.
To prevent fungal diseases in tomato plants, you can make use of coffee grounds as studies have examined the effects of coffee on fungal activity in the soil. Through these studies, caffeine has been linked to the suppression of various fungal strains. Also, there is soil amendment which aids in the increase of microbial activity thereby suppressing fungal diseases.
3) ELIMINATION OF SLUGS
Slugs are known to be a common problem in tomato gardens thus, leading to the suggestion of a plethora of remedies, each known to provide a successful war against slugs and snails. Coffee grounds contain caffeine which is harmful to slugs and can kill them.
4) COFFEE GROUNDS IN COMPOST
Coffee grounds serve as a basic part of the list of ‘green materials’. An addition of 20% of coffee grounds to your compost mix is ideal. It can also be around 30% but over 30% can lead to an inhibition of decomposition. Rather than having your coffee grounds wasted, save them and add them to your compost pile. This gives excellent results with little or no negative effects.
Related: Do Cucumbers Like Coffee Grounds? Step By Step Answer
Coffee grounds are excellent for tomatoes and can give your tomato plants a healthy look with lots of fruits. However, avoid overloading your tomatoes with too much coffee grounds as tomatoes like slightly acidic soil and not overly acidic soil. You can also add them to the compost pile. If however, you want to use them directly in the garden, you can dry them out first as drying them makes them easier to spread. Coffee grounds contain nutrients such as nitrogen, magnesium, potassium, copper e.t.c and are known to repel ants and slugs. Learn about adding coffee grounds to tomato plants.