With a passion for growing installed at an early age, I have always been happiest outdoors in nature. After training as a professional gardener and horticultural therapist, I currently run horticultural therapy and community kitchen gardens in the UK, helping others access the many physical and mental health benefits of growing vegetables, fruit and plants. Favourite fruit: apples and pears Favourite vegetable: asparagus
As a hungry perennial plant, rhubarb benefits from some extra nutrition. Discover how and when to fertilise rhubarb for a bumper harvest.
Grown for its edible stems, rhubarb (Rheum x hybridum) is generally easy to care for. However, as a hungry feeder, it is important to provide the essential nutrients to support its growth during the growing season. Read on to find out which fertiliser to use and when to apply it to ensure that you have a bountiful rhubarb crop come spring.
As a perennial vegetable, rhubarb dies back in the winter before putting on strong new growth come spring. When mature, rhubarb plants are large and some rhubarb varieties can grow more than 1m high and wide. Hence, it is no surprise that they use up a lot of energy producing their large stems and foliage. To support their growth and help provide the nutrients required, you can feed rhubarb with a fertiliser, especially if the soil is poor. If you grow rhubarb in a pot, applying a fertiliser is particularly important because, due to the limited quantity of soil, the nutrients can quickly run low or leach out of the pot when watering.
Rhubarb is a popular perennial vegetable prized for its tart and colorful stalks As a relatively hardy plant, rhubarb thrives when provided with rich, fertile soil This leads many gardeners to wonder – can used coffee grounds provide extra nutrients for rhubarb or are there downsides to this practice? In this article, we’ll explore the effects of using coffee grounds on rhubarb to help you make the best choice for your crop.
An Overview of Rhubarb’s Needs
To understand if coffee grounds are beneficial for rhubarb, it’s important to first look at the plant’s ideal growing conditions
Rhubarb prefers soil with a pH between 6.0-6.8. It requires nitrogen for healthy leaf growth, phosphorus to stimulate root and flower development, and potassium to improve disease resistance and water regulation. The plant also needs plenty of organic matter for moisture retention and nutrient release.
With this in mind, let’s break down the potential pros and cons of using coffee grounds.
The Potential Benefits of Coffee Grounds for Rhubarb
Coffee grounds offer some clear advantages when used for rhubarb
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Rich in nitrogen: Coffee grounds contain around 2% nitrogen content. This can provide a useful boost to soils lacking in this important nutrient. More nitrogen encourages lush, green foliage.
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Increases organic matter: Introducing coffee grounds to your soil adds valuable organic matter. This can improve moisture retention, soil structure and microbial activity.
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May supply other nutrients: Coffee grounds contain small amounts of phosphorus, potassium and magnesium. Every bit helps when building soil fertility.
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pH lowering effect: The slightly acidic nature of coffee grounds could help lower pH in alkaline soils. Rhubarb prefers a more acidic environment.
Possible Drawbacks of Using Coffee Grounds for Rhubarb
However, there are also some potential downsides to keep in mind:
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Too much acidity: While a small pH change can be beneficial, excessive coffee grounds can make the soil overly acidic for rhubarb’s preferences.
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Nutrient imbalances: Too many coffee grounds may lead to disproportionate amounts of nitrogen. This could inhibit the uptake of other nutrients.
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Threat of fungi or mold: The damp, nitrogen-rich environment created by coffee grounds carries a risk of promoting mold growth.
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Caffeine content: Coffee contains caffeine, which may accumulate to toxic levels in some plants. However, rhubarb is generally tolerant to typical exposure.
Best Practices for Using Coffee Grounds on Rhubarb
Coffee grounds can be a helpful addition to rhubarb beds if applied in moderation using smart techniques:
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Test your soil pH and only use grounds to slightly lower overly alkaline soils. Don’t overdo it.
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Mix grounds thoroughly into the top layers of your soil to prevent mounding.
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Combine with other organic materials like compost or manure to create a balanced nutrient profile.
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scatter lightly around plants and water in well. About 1/2 inch, once or twice a season is sufficient.
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Monitor rhubarb health and ease off if signs of over-acidity appear.
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Ensure proper drainage to avoid waterlogging from excess grounds.
Alternative Organic Amendments to Coffee Grounds
Coffee grounds are just one option. Some other excellent organic additions for rhubarb include:
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Compost: Boosts soil nutrients, organic matter and beneficial microbes. A versatile choice.
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Well-rotted manure: Provides a slow release of nitrogen, phosphorus and potassium as it breaks down.
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Grass clippings: Offers nitrogen and potassium. Allow to compost fully before applying.
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Seaweed or kelp: Supplies micronutrients, alkaloids and growth hormones.
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Wood ash: Raises pH in acidic soils. Best applied in smaller amounts.
To summarize, coffee grounds can potentially provide some useful benefits to rhubarb in the form of nitrogen, organic matter and pH lowering capacity. However, excessive use may tip the scales to overly acidic conditions, nutrient issues or other problems.
With care and moderation, coffee grounds can be a helpful addition. But they are just one part of an overall soil fertility regimen. Maintaining the ideal balance through pH testing, plant monitoring and a diverse mix of organic amendments leads to the best results.
The key is working within the plant’s preferences and applying coffee grounds judiciously to harness the upsides while avoiding the downsides. This takes some trial and error to fine tune for your specific growing conditions. If in doubt, you can’t go wrong boosting your soil with compost and manures rather than overdoing it with grounds. With a thoughtful, attentive approach, coffee grounds can be one useful tool in growing thriving rhubarb.
You want to know who’s behind Plantura?
With a passion for growing installed at an early age, I have always been happiest outdoors in nature. After training as a professional gardener and horticultural therapist, I currently run horticultural therapy and community kitchen gardens in the UK, helping others access the many physical and mental health benefits of growing vegetables, fruit and plants. Favourite fruit: apples and pears Favourite vegetable: asparagus
As a hungry perennial plant, rhubarb benefits from some extra nutrition. Discover how and when to fertilise rhubarb for a bumper harvest.
Grown for its edible stems, rhubarb (Rheum x hybridum) is generally easy to care for. However, as a hungry feeder, it is important to provide the essential nutrients to support its growth during the growing season. Read on to find out which fertiliser to use and when to apply it to ensure that you have a bountiful rhubarb crop come spring.
As a perennial vegetable, rhubarb dies back in the winter before putting on strong new growth come spring. When mature, rhubarb plants are large and some rhubarb varieties can grow more than 1m high and wide. Hence, it is no surprise that they use up a lot of energy producing their large stems and foliage. To support their growth and help provide the nutrients required, you can feed rhubarb with a fertiliser, especially if the soil is poor. If you grow rhubarb in a pot, applying a fertiliser is particularly important because, due to the limited quantity of soil, the nutrients can quickly run low or leach out of the pot when watering.
When to feed rhubarb
The best time to feed rhubarb is in spring or early summer to support the new season’s growth. Slow-release fertilisers or organic matter tend to break down slowly and can feed plants for around 2 to 3 months, meaning that one application may be enough for the year. If your rhubarb appears to be struggling, you can apply a second dose in early summer. However, it is important not to fertilise rhubarb with a nitrogen-based fertiliser after the end of June, as this may encourage new growth when the plant wants to enter its dormancy in the autumn.
You can also fertilise rhubarb at the time of planting. Before planting rhubarb, you can prepare the ground by removing any weeds and adding around 40L per sqm of well-rotted manure, garden compost or a balanced granular fertiliser to the soil to enrich it.
5 Simple Truths About Adding Coffee Ground & Egg Shells To The Garden
FAQ
How to use coffee grounds for rhubarb?
When fertilising rhubarb with coffee grounds, a handful or two spread around the base of the plant and gently worked into the soil is generally sufficient and should not affect the pH levels of the soil adversely.
What plant benefits most from coffee grounds?
Acid-loving plants, like azaleas, blueberries, camellias, hydrangeas, and rhododendrons, generally benefit the most from coffee grounds. These plants thrive in slightly acidic soil, and coffee grounds can help lower the soil’s pH, making it more hospitable.
What is the best fertilizer for rhubarb?
Apply 2 to 3 inches of composted manure, compost or ½ cup of an all-purpose garden fertilizer, such as 10-10-10, around each plant in early spring (now). Once growth starts to occur, apply fertilizer again. And then, in the fall, mulch your plants with 6 inches of compost or composted manure and leaves.Apr 6, 2016
What is the secret to growing great rhubarb?
- The best soil for rhubarb is well-drained.
- Loamy soils are better for rhubarb growth than sandy soils. …
- Soil pH is not important. …
- The rhubarb plant is a “heavy feeder.” The plant must take in large amounts of nutrients from the soil to produce its large stalks and leaves.