One of the most popular flowers for flower arrangements and backyard gardens is the dahlia. These summer-blooming flowers have bright colors and interesting shapes that can make any yard look more exotic. You likely want your dahlias to have the biggest, boldest blooms possible as a gardener. This can be done in part by giving them the right nutrients. Did you know that used coffee grounds are a great way to feed dahlias?
This complete guide will talk about the benefits of using coffee grounds on dahlias and give you advice on how to do it right. Let’s dig in!.
What Nutrients Do Coffee Grounds Provide for Dahlias?
Coffee grounds are full of important nutrients that dahlias need to grow and flower in a healthy way, such as
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Nitrogen Critical for promoting lush, green vegetation and stems. Dahlias need ample nitrogen to support their large blooms.
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Phosphorus: Helps develop strong root systems and encourages bud and flower production.
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Potassium: Important for overall plant vigor and disease resistance. Also aids in flower formation.
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Magnesium and calcium: Trace minerals that contribute to plant structure and development.
The nutrients in used coffee grounds are readily available for plant uptake since the grounds are already broken down from the brewing process. This makes them an organic and quick-release fertilizer option.
Why Are Coffee Grounds Beneficial for Dahlias?
Using coffee grounds as a soil amendment for dahlias provides several advantages beyond just nutrients:
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Improves soil structure and texture when mixed into the top layers of soil.
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Increases the soil’s ability to hold moisture and nutrients due to added organic matter.
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Lowers pH levels slightly to make soil more acidic, which dahlias prefer.
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Provides a slow-release fertilizer that is less likely to burn plants compared to commercial fertilizers.
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Repurposes spent coffee grounds, reducing kitchen waste.
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Deters garden pests like slugs and snails due to the caffeine content.
As you can see, coffee grounds check a lot of boxes when it comes to benefits for dahlias and garden soil in general.
Are There Any Risks of Using Coffee Grounds for Dahlias?
While coffee grounds are a great organic fertilizer option, there are a few potential downsides to be aware of:
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They can lower soil pH too much if overapplied, making the soil excessively acidic for dahlias.
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Contains caffeine which in very high concentrations can inhibit plant growth.
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May provide too much nitrogen if layered thickly, causing excessive foliage growth at the expense of flowers.
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Can create drainage issues if allowed to form a dense, compressed layer on top of the soil.
However, these risks are easily avoidable by following the proper application guidelines covered next. The benefits clearly outweigh the potential downsides.
How to Apply Coffee Grounds to Dahlias
To safely apply used coffee grounds to dahlias, follow these recommendations:
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Mix grounds into soil before planting or sowing seeds. A ratio of 1 part grounds to 10 parts soil is a good starting point.
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Top dress around established plants every 2-4 weeks during the growing season. Apply a thin 1⁄2 inch layer and lightly work it into the top 1-2 inches of soil.
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Water thoroughly after applying to help dissolve nutrients and avoid drying out surface roots.
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Alternate coffee grounds with other organic amendments like compost or manure to provide a diverse nutrient profile.
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Monitor soil pH periodically. Aim for a slightly acidic pH around 6.5. Add lime if pH drops too low.
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Never allow wet coffee grounds to touch plant stems or leaves directly, as this can promote rot and disease.
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Discontinue use 1-2 months before expected harvest time. This allows the nitrogen levels to normalize.
By following these best practices, you can harness the perks of coffee grounds while avoiding potential issues from overuse.
When to Apply Coffee Grounds to Dahlias
Timing is an important factor when fertilizing dahlias with used coffee grounds:
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Early spring is ideal right before the plants emerge from tubers. This gives the nutrients time to integrate into the soil.
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Continue applying every 2-4 weeks after plants are established and actively growing.
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Taper off use in mid to late summer as buds form and the plants focus energy on flowering rather than foliage growth.
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Discontinue use at least 1 month prior to first expected frost.
Adjust timing as needed based on your local growing season and the specific growth stage of your dahlia plants. Pay attention to how the plants respond and adjust your coffee ground application accordingly.
Other Tips for Using Coffee Grounds on Dahlias
Here are some additional pointers to get the most out of using coffee grounds for your dahlias:
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Source grounds from organic, non-flavored coffee when possible. Avoid using sugary or heavily processed grounds.
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Consider composting grounds for a few months before application. This helps moderate nitrogen levels.
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Water plants thoroughly after applying grounds to prevent root burn from concentrated nitrogen.
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Combine with high phosphorus fertilizer sources like bone meal to balance the high nitrogen content.
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Monitor soil pH and nitrogen levels regularly to avoid over-fertilization.
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Scatter grounds lightly over entire plant area, not just at the base or in rows.
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Rake up and remove any grounds that remain on top of soil to prevent fungus issues.
The Bottom Line
Coffee grounds can be a safe, effective, and eco-friendly fertilizer choice for dahlias when applied correctly. The nitrogen, phosphorus, potassium, and organic matter in used grounds provides tangible benefits for dahlia growth, flowering, and soil health. By following the best practices outlined above, you can put your leftover morning coffee to work in your garden!
Try incorporating some used grounds into your dahlia beds this season and see the dramatic results for yourself. Just be sure not to overdo it, and monitor your plants and soil closely. Done right, coffee grounds can help your dahlias produce their most dazzling blooms yet. So brew up another batch for your plants while you sip on your own morning mug!
Drawbacks of Coffee Grounds:
- Acidification: Too much acid can damage your plants. (check your soil regularly) .
- Slow release of nitrogen: Coffee grounds do have nitrogen in them, but it’s slowly released. This might not be enough for dahlias that bloom a lot, especially during the flowering season, so you will need to add more fertilizers.
- Fungus risk: If it’s humid, coffee grounds can attract fungus and help it grow.
Choosing The Right Fertilizer
Before fertilizing our dahlias, it is a good idea to understand what is already in your soil and what the nutrient requirements of dahlias are.
Soil Testing: Before applying any fertilizer, test your soil to determine its nutrient levels and tailor your fertilization accordingly.
Dahlia Nutrient Needs: Dahlias are big bloomers and heavy feeders. While they appreciate a balanced diet, understanding their specific preferences will help you keep them thriving. You will want to prioritize nitrogen during the growth phase and phosphorus during the blooming phase. Potassium benefits overall plant health.
Here’s a breakdown:
- Nitrogen (N): Important for healthy leaf growth, especially in the beginning. But too much N can make flowers and stems not grow as well. During the growing season, you should aim for a moderate N content in your fertilizer, around 10–15%.
- It is very important for flower growth and strong root systems. Daisy plants usually don’t need a lot of P, so look for fertilizers that have a slightly higher P content than N, around 10 to 15 percent.
- Potassium (K): Boosts healthy growth, stress resistance, and disease tolerance. Dahlias do better with fertilizer that has a relatively high K content, around 15 to 20 percent.
- Boron (B): Aids in pollen formation and seed production. When plants are flowering, a small amount of boron fertilizer can help them make strong blooms.
- Magnesium (Mg): Essential for chlorophyll production and healthy plants. Deficiencies can show up as yellowing leaves. Most complete fertilizers will contain sufficient magnesium.
Are Coffee Grounds Good For Plants?
FAQ
How do you fertilize dahlias with coffee grounds?
Sprinkle a layer of coffee grounds on top of your soil before the growing season and work into your well-drained soil. Used coffee grounds contain about 2% nitrogen, about 1/3% phosphoric acid, and 1% potash, which the Dalias love. This will give your healthy tubers a good start to the growing season.
What flowers should you not put coffee grounds on?
In most cases, the grounds are too acidic to be used directly on soil, even for acid-loving plants like blueberries, azaleas and hollies. Coffee grounds inhibit the growth of some plants, including geranium, asparagus fern, Chinese mustard and Italian ryegrass.
What is the best fertilizer for dahlias?
Bat guano and blood meal are good fertilizers. Of course all types of aged manures are the classic fertilizers for organic gardeners. Chicken manure works great but needs to be applied in the Fall as it is too “hot” (too much nitrogen all at once) for dahlias.
How can I make my dahlias bloom better?
Managing Dahlias for Maximum BloomsPinch and Propagate. Staking. Proper Watering. The Importance of Fertilizer. Cutting Stems to Maximize Blooms. Deadheading is a Must. Use Organza Bags for Pristine Blossoms. Start With High-Performing Varieties.
Are coffee grounds good for dahlias?
Lastly, the potassium in coffee grounds can help a plant’s health by making it less likely to get sick and making its cells stronger. All of these things work together to give your dahlias a complete and balanced nutrition package that helps them grow in the best way possible.
Can one eat the flowers of a calabash tree?
People can eat them because they are not poisonous, but studies have not shown that they are nutritional or medicinal.
Can you use leftover coffee grounds to brew dahlias?
As it turns out, the leftover coffee grounds marinating in your coffee brewer contain organic matter that can help your dahlias flourish. You can easily take advantage of these benefits by simply collecting used grounds from your daily brew. Spread the grounds evenly around the base of the dahlia plants, being careful to not form any clumps.
How do you grow dahlias with coffee grounds?
Gently work the coffee grounds into the soil using a gardening tool or your hands. This will help ensure that the nutrients are evenly distributed and accessible to your dahlias’ roots. Water the dahlias after applying the coffee grounds to help them absorb the nutrients more effectively.
How often should you reapply coffee grounds to a dahlia plant?
For best results, reapply the coffee grounds once a week consistently throughout the growing season, but avoid overuse, as excessive nitrogen can lead to imbalances. Because dahlias thrive in slightly acidic soil, it can be a good idea to test the soil’s pH before applying the coffee grounds to it.
Are coffee grounds good for lilies?
Coffee grounds can help adjust soil pH, supply essential nutrients, and improve soil structure. Lilies (Lilium spp.): Elegant, showy flowers that grow from bulbs and come in various colors and forms. Optimal pH: 6.0-6.5. Coffee grounds can provide vital nutrients, especially nitrogen, for healthy growth and abundant blooms.