In the vast realm of gardening, the use of coffee grounds as a natural fertilizer has garnered widespread attention and enthusiasm.
Rich in essential and beneficial nutrients, coffee seems like an organic elixir for promoting healthy plant growth. However, it’s important to note that not all plants like coffee grounds.
Some display a distinct aversion to coffee grounds, requiring us to consider alternative fertilizing methods to ensure their optimal well-being. For this, we have to find out which of these green buddies don’t like coffee grounds.
In this comprehensive guide, we delve into the kingdom of plants that don’t like coffee grounds, unveiling the underlying reasons behind their preferences. By understanding these nuances, gardeners can make informed decisions and tailor their fertilization practices to create thriving gardens that cater to the diverse needs of each plant.
So, read as we embark on this journey of discovery concerning the plants and flowers that don’t like coffee grounds, all the while providing valuable insights and recommendations to help you cultivate flourishing green spaces.
Let’s begin!
Effects of Coffee Grounds on the Soil!
Let us look and understand the effects that coffee imposes on the soil and, in turn, on the plants.
The very first thing that happens after adding coffee grounds to the soil is an increase in nitrogen levels which can go as high as 1.45%. This causes the soil acidity to rise too. This increase in soil acidity is the most important factor that will determine if the plant will survive or die.
Secondly, the caffeine in brewed coffee is another element that is one of the major causes of damage.
In the coffee tree, caffeine is originally used as a natural weed killer.
And lastly, retention of water causes a clogging and waterlogging problem, which then eventually leads to root rot that can be fatal for the plant.
Top 8 Plants that Don’t Like Coffee Grounds!
Before going any further, note that this is not a comprehensive list; only major plants are listed below, so before buying a plant, do your research about its optimal soil pH level requirements and other important things.
Here are some plants that do not like coffee grounds as part of their fertilization routine:
1. Rosemary
While rosemary is generally a hardy and adaptable herb, it prefers well-drained soil with a slightly alkaline pH.
Coffee grounds are acidic and can lower the pH of the soil, which may not be ideal for rosemary.
It is best to avoid using coffee grounds as a fertilizer for rosemary. Though sometimes rosemary does like a little acidic soil, not too much.
2. Tomatoes
Tomatoes prefer slightly acidic soil with a pH between 6.0 and 6.8.
While coffee grounds are acidic, they also contain high levels of nitrogen, which can promote leafy growth at the expense of fruit production in tomatoes. Using coffee grounds as a primary fertilizer for tomatoes may hinder their fruiting capacity.
Moreover, coffee grounds have been ineffective against the problem of snails and slugs.
3. Orchids
Orchids are delicate little flowers with specific growing requirements.
While coffee grounds can provide some essential nutrients in the form of organic matter, they are not suitable as a primary fertilizer for orchids.
That is because the kind of soil in which orchids grow is not rich in organisms that can break down the nitrogen compounds in the coffee, so it is useless to put a coffee treat on the orchid plant anyway because it cannot consume that nitrogen.
Furthermore, coffee is not too strong to kill or keep away the snails and is too acidic to raise the pH of the potting soil. It ruins the balance. Orchids require a well-draining, airy potting mix, and coffee grounds can retain moisture, leading to root rot.
4. Lavender
Lavender plants prefer well-drained soil with a slightly alkaline to neutral pH.
Coffee, being acidic, can disrupt the pH balance of the soil and affect the overall health of lavender plants.
It is advisable to avoid using coffee grounds as a fertilizer for lavender.
5. Asparagus
Asparagus plants have specific soil requirements, preferring slightly acidic to neutral soil.
Coffee, being acidic, can alter the pH of the soil, which may not be suitable for asparagus growth.
It is recommended to refrain from using coffee grounds as a fertilizer for asparagus. And if you do want to use it, do not apply it directly onto the asparagus crowns.
6. Geranium
Geraniums are popular flowering plants, but they may not like coffee grounds as a primary fertilizer.
Coffee grounds are high in nitrogen, which can promote excessive leaf growth in geraniums at the expense of flower production.
And secondly, it makes the soil too acidic, in which geranium is not able to survive. It is best to use an alternative fertilizer specifically formulated for flowering plants.
7. Italian Ryegrass
Italian ryegrass is a cool-season grass often used for forage or erosion control.
While coffee grounds can provide some organic matter, they may not be able to absorb these essential nutrients because their roots are just not capable enough and hence are not able to provide the balanced nutrition required for healthy growth.
It is advisable to use specialized grass fertilizers for this purpose.
8. Pothos
Pothos, a popular indoor plant, is generally not recommended to be fertilized with coffee grounds, although the rich nutrients in the coffee can be very beneficial to this plant.
The only major concern while using coffee as a fertilizer for this is that they do not thrive in acidic soil conditions. Moreover, coffee grounds can retain moisture, leading to overwatering and potential root rot in pothos plants.
It is advisable to use appropriate indoor plant fertilizers for pothos instead. So, if you are using coffee grounds, add these to the mulch or compost.
Succulents and Cacti Don’t Benefit from Coffee Grounds!
Succulents and cacti do not typically benefit from coffee grounds due to their sensitivity to moisture, preference for well-draining soil, and pH requirements.
These plants are adapted to arid conditions and can be harmed by the moisture-retaining properties of coffee grounds, increasing the risk of overwatering and root rot.
Additionally, adding coffee grounds alone can disrupt the soil’s drainage, which is crucial for succulents and cacti.
Where in the Garden Should You Not Use Coffee Grounds?
While coffee grounds can be beneficial for certain garden areas, there are a few areas where you should avoid putting coffee grounds or using them:
Near Acid-Loving Plants: Coffee grounds are acidic, and while this can benefit acid-loving plants like azaleas, rhododendrons, and blueberries, it’s best to use them sparingly. Excessive use of coffee grounds can disrupt the pH balance of the soil and harm other plants.
Near Plants that Prefer Alkaline Soil: Plants that thrive in alkaline soil, such as lilacs and asparagus, generally prefer a higher pH level. Coffee grounds, being acidic, can lower the soil’s pH, which might be detrimental to these plants.
Near Seedlings and Young Plants: Coffee grounds can inhibit the germination and growth of some seeds due to their acidity. When using coffee grounds near seedlings or young greens, it’s better to compost them first or use a diluted solution.
Indoor Potted Plants: Coffee grounds can attract pests like fruit flies, especially when used in indoor potted plants. It’s advisable to avoid using coffee grounds directly in pots indoors to prevent such issues.
If you’ve never used coffee grounds, let’s see how to use them properly.
How to Use Coffee Grounds Effectively?
Following are some tips to use used coffee grounds in a beneficial way:
Composting: Add coffee grounds to your compost pile to enrich it with nitrogen and create nutrient-rich compost.
Mulching: Use coffee grounds as a natural mulch around plants to suppress weeds, retain moisture, regulate soil temperature, and improve soil structure.
Balance carbon-to-nitrogen ratio: When composting coffee grounds, mix them with other organic materials to maintain a balanced carbon-to-nitrogen ratio. Add equal amounts of brown materials (e.g., dried leaves) to avoid excessive acidity.
Leave Them to Break Down: Allow coffee grounds to decompose gradually over time. They will break down and release nutrients into the soil as they decompose.
That’s all.
Conclusion!
In conclusion, while coffee grounds can be a beneficial addition to garden soil and compost, there are certain plants that generally do not appreciate their use.
Plants that prefer slightly alkaline soil, seedlings and young plants, and indoor potted plants are typically better off without the direct application of coffee grounds. Acid-loving plants can benefit from coffee grounds but should be treated with moderation. Succulents, cacti, and vegetable plants, due to their sensitivity to moisture, are generally not suited for coffee grounds.
So, understanding the needs and preferences of different plants is crucial when deciding whether or not to use coffee grounds in specific garden areas.
Regards.