Coffee is one of the most popular beverages in the world—a beverage that millions of people rely on to help start their day off on the right foot. And while certainly enjoyable and beneficial to humans as a get-up-and-go beverage, the used grounds that remain after we have brewed a cup or pot of coffee may be even more beneficial to your garden.
As organic matter, coffee grounds are chock full of a variety of natural substances like nitrogen, potassium and other minerals—substances that have been proven beneficial to many plants and the soil in which they are grown. To illustrate this, below we have highlighted several unique ways to use coffee grounds in your garden, and explained why each of these strategies is beneficial.
The Many Ways to Use Coffee Grounds in Your Garden
Coffee grounds can do wonders for your garden and the plants that inhabit it. Plants that love acidic soil will do great in earth that is treated with coffee grounds; and if the ph levels ever get too high to support other plants within your garden, you can always wash subsequent coffee grounds to lower their ph levels.
Many expert gardeners and botanists have long touted the benefits of coffee grounds. They represent a safe and effective way to boost any garden without the use of harsh pesticides, fertilizers or chemicals. So, before you toss the grounds from your French press, consider using them in your garden. Here are just a few of the ways to efficiently and effectively use coffee grounds in your garden.
Helping (Certain) Plants Thrive
Coffee grounds are a great way to help boost certain types of plants. As we mentioned very briefly above, many acid-loving plants can benefit greatly from having fresh coffee grounds mixed into the soil near where they are planted. However, you should always be careful where you place those coffee grounds, as not all plants will do well when the ph level of the soil is raised using this type of organic matter.
According to master gardeners, there are several varieties of flowers that should definitely be grown in soil that is more acidic—soil into which coffee grounds are added. Three of these varieties include:
- Hydrangeas. Hydrangeas include a group of 70-75 species of flowering plants that are native to the Americas, as well as to southern and eastern Asia.
- Lilies. Grown from bulbs, lilies are herbaceous flowering plants that are important in the culture and literature in much of the world.
- Azaleas. Azaleas are shrubs that bloom in the springtime with brilliant flowers that can last several weeks. These shade loving plants prefer to be grown near or underneath trees.
Coffee grounds can also help in the growing of vegetables. Root veggies like carrots and radishes do particularly well when coffee grounds are added to the soil during the planting phase; and fruit bushes like blueberry and raspberry can likewise receive a boost from the extra ph in the soil.
Coffee grounds have allelopathic properties, which can actually suppress certain weeds from growing in your garden. However, you must be careful, as those same properties can simultaneously bring harm to other plants like tomatoes.
Increase Nitrogen Levels in the Soil
Coffee grounds are chock full of nitrogen—one of the most necessary substances for growing a wide range of plant life in your garden. Putting coffee grounds into your compost pile will greatly increase the nitrogen level; and when that compost is then added to your garden soil it creates a virtual hot bed for the growing of all kinds of flowering plants, fruits and vegetables.
Adding coffee grounds to your soil can help promote aeration of that soil. So why is aeration important? Soil that is compacted can be a major problem for the plants within that soil. When the soil is too compressed, the roots of plants are unable to get the nutrients they need. However, when the soil is aerated or broken up using organic matter like coffee grounds, small holes are created in the soil. It is through these tiny holes that necessary substances like oxygen, nitrogen, water and nutrients are delivered to the roots of plants. This, in turn, makes the roots healthy—and healthy roots can become strong and create a plant that is equally healthy.
If you live in a dry and arid region, you have no doubt witnessed firsthand the negative consequences those hot and rainless conditions can have on your soil. In southern, dry areas, where droughts are common, ever the hardiest, most drought-resistant plants can struggle to get enough water and nutrients to thrive. Fortunately, by simply adding coffee grounds to this dry, water-deficient soil, you can actually improve the soil’s water retention. According to scientists, the improved water retention brought about by adding coffee grounds translates to greener, hardier plants. In other words, improved water retention means the plants will be able to do more with less water.
The direct opposite of water retention, but also equally important for soil, is drainage. When soil is unable to drain properly, it can create stagnancy in the water both above and below the soil. Unlike fresh water, which helps plants to thrive, stagnant water can leave your plants very vulnerable to a wide range of diseases. Conversely, soil with good to excellent drainage can ensure that the roots of your plants receive the adequate amount of water they require while simultaneously allowing any excess water to flow away from the plants and their roots. Coffee grounds help to slowly break down soil, which in turns allows for better drainage and happier, disease-free plants.
If you are squeamish, the thought of earthworms crawling through your soil is probably not a pleasant one, but these creepy crawlers can actually be VERY good for your garden. Whether you love them or hate them, worms are a gardener’s best friend. They slither through the soil by tunneling, which creates natural vents through which oxygen, water and other nutrients can flow. Worms also eat plenty of organic matter, and the excrement that is a byproduct of those meals contains nutrients that can help many plants to flourish. Coffee grounds are organic matter, so by adding them to your soil you can actually attract earthworms. This, in turn, will provide your plants with valuable nutrients, create the perfect degree of aeration through which nutrients, oxygen and water can flow, and can even help with soil drainage.
Keep Snails and Slugs at Bay
Pesticides for the control of plant eating snails and slugs are not only expensive, they can be quite dangerous. Snail pellets and other forms of pesticide can be harmful to pets and small children, while coffee grounds can repel these pests in a safe and effective manner. The odor and makeup of coffee grounds are repulsive to snails and slugs and will hence keep the slow crawling pests from proliferating in your garden.
In summary, coffee grounds can be beneficial to your garden in a number of ways. Fresh coffee grounds can help certain plant species to thrive (and even suppress some weeds); attract earthworms; help with aeration, water retention and drainage; add nitrogen to your soil; and even keep certain plant-eating pests away like snails and slugs. However, as with any gardening hack it’s important to do some research before aimlessly adding coffee grounds to the soil. Remember, while coffee grounds may indeed help some plants to flourish, their acidic and allelopathic properties can do damage to other types of plants.