Coffee isn't just great to drink, but it's also great in the garden. Some plants absolutely love it and thrive on coffee. Did you know that Passionfruit and Citrus love a bit of coffee?
What are some of the benefits of coffee grounds in the garden?
- Coffee grounds increase the amount of nitrogen and potassium in soil, and these are great growth boosters when used in moderation.
- Coffee grounds can be acidic if used fresh, but used coffee capsules have had their acidity removed by the process of running water over them.
- The addition of coffee grounds can improve soil drainage.
- Coffee grounds can help soil retain moisture.
- Coffee grounds repel some pests, such as snails and slugs.
- Coffee grounds attract earthworms. Everything seems to love a good cafe, including your local earthworms it seems. Whilst the earthworms are getting their caffeine fix, they'll have a brunch of spider mites and aphids, so win-win for the gardener.
- Coffee grounds may deter cats from using your garden to do their business.
- Coffee grounds have some allelopathic properties so may suppress some weeds, however, these properties also adversely affects tomato plants - so use with coffee with caution around tomatoes.
- Coffee grounds may suppress some fungal pathogens.
How to reuse your Ola coffee capsules in the garden
- Our preferred method: Add your used Ola capsules plus all the packaging including the outer wrap to your compost bin or worm farm. Coffee grounds are green compost material, the packaging is brown compost material. Our worm colony has exploded since adding Ola capsules to their bin.
- On the Gardening Australia page there's this tested compost recipe from a retired scientist Stuart Rodda which we need to incorporate into our ever growing collection of compost bins:
- 2 shovel loads of coffee grounds
- 2 shovel loads of sawdust (avoid black walnut and any treated timbers)
- Mix together
- Add your used Ola coffee capsules straight to the soil. To do this, break them apart to set the coffee free, then dig it into the soil. The paper and sugarcane portion of the capsules can also go into the soil, or you can compost these separately. Don't add too many, everything in moderation including nitrogen and potassium.
- Mix your used Ola coffee grounds into your mulch (put the paper part into the compost).
- Create a liquid coffee "fertiliser". To do this, put your used Ola capsules in a pot (a mason jar is perfect) and cover them in hot water, then put a lid on. Stick the pot on a windowsill for a few days until the paper capsules have disintigrated. You should then dilute this mixture down to around 1 teaspoon of grounds per 3 litres of water.
- Use your used Ola coffee capsules as seed pods. We've tried a few different methods of this and have successfully grown sunflowers and tomatoes from seed. The best way is to put the seed in the used Ola capsule, put the capsule in a tall mason jar, add enough water to cover the capsule, then pop it on a windowsill without a lid. Make sure you keep the water above the top of the capsule as coffee grounds dry out quickly. You will need to plant out your seedling once it gets big enough as it needs more than just coffee to grow big and strong. Here's a sunflower we grew from a seed:
Plants and vegetables that may enjoy a little coffee.
- African Violets
- Azaleas
- Blueberries
- Carrots
- Christmas Cactus
- Citrus
- Cyclamen
- Hydrangeas (coffee helps them turn more blue)
- Jade Plant
- Lillies
- Miniature Roses
- Moth Orchids
- Norfolk Island Pine
- Passionfruit
- Philodendrons
- Pothos
- Radishes
- Roses
- Snake Plant
- Spider Plant
Information thanks to:
- Our own experiments at home with various compost bins, worm farms, and plants.
- https://www.tipsbulletin.com/qa-which-plants-like-coffee-grounds/
- https://www.wellandgood.com/what-plants-like-coffee-grounds/
- https://www.abc.net.au/gardening/factsheets/coffee-compost/10089756
- https://www.epicgardening.com/composting-with-coffee-grounds/
- https://www.gardeningknowhow.com/composting/ingredients/coffee-grounds-gardening.htm
- https://www.bhg.com.au/coffee-grounds-for-plants-are-they-good-for-your-garden
- https://www.hunker.com/13723317/plants-that-love-coffee
- https://balconygardenweb.com/houseplants-that-love-coffee-grounds-for-plant-growth/