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You have some used coffee grounds in your kitchen and wonder if they’d be any good for the garden, specifically, your new azalea bush. It looks beautiful, but can it safely benefit from coffee grounds? Are coffee grounds good for azaleas?
Azaleas are one of the most acid-loving popular plant species and are fond of coffee grounds. They can benefit from coffee grounds throughout spring and summer, especially if grown in alkaline or neutral soil. Fertilizing with coffee grounds off-season, however, can cause damage to the shrub.
Keep reading to learn more about how to apply coffee grounds to your azaleas, the best ways to nourish azaleas with coffee grounds, and other uses for coffee grounds around the home and garden.
Do Azaleas Like Coffee Grounds?
Azaleas are especially fond of coffee grounds, thanks to the grounds’ acidic nature. You’re likely to see azaleas somewhere on the top in lists of acid-loving plants and shrubs. This is because azaleas are one of the most popular acid-loving plant species you can grow, they’re easy to care for, and they’re well-loved for their beautiful branches full of striking flowers.
Azaleas prefer a soil pH level of 4.5 to 6.0. This is a fairly wide range, meaning that azaleas can do great in mildly or moderately acidic soil. Contrast this with the acid tolerance of a rose, which thrives best in soil that is 6.0 to 6.5. That’s a much more limited range, making roses more sensitive and specific in their needs.
On the other hand, Azaleas are tough, hardy flowering shrubs that soak up the acid and use it to burst forth in pink, white, fuschia, or purple blooms. Other colors like orange and yellow can sometimes be found, too. The more acidic the soil, the more azaleas seem to thrive. And this acidity, among other properties, makes coffee grounds an excellent fertilizer for azaleas and great for your soil.
What Do Coffee Grounds Add to the Soil?
Coffee grounds add moderate quantities of acid to the soil. The acidity brings with it healthy amounts of nitrogen and potassium, which nourish the soil and is absorbed by the azalea’s root system as food. If coffee grounds are added to the soil over some time, they can lower the pH of the soil from alkaline to mildly acidic or from neutral to moderately acidic.
Coffee grounds are also especially loved by earthworms. As food and as a grainy aid to earthworm digestion, coffee grounds can help attract and feed the life forms that make the soil richer, healthier, and more nutritious.
The rough texture of coffee grounds also helps break up the soil a bit before decomposing, which can be especially good for soil aeration. The more aerated soil is, the easier it will be for the root systems of your azaleas to absorb nutrients. Coffee grounds also improve soil drainage, which makes for a healthier root system, and better plant growth overall.
So now that you know the benefits of adding coffee grounds to your azaleas, where can you get some easily?
How Can I Get Coffee Grounds?
Coffee grounds are easy to obtain. The simplest way to get a hold of coffee grounds would be after your morning pot or cup of coffee. You can use the grounds from a drip coffee maker, pour-over unit, disposable Keurig cup, or a French Press.
You’ll want to store your coffee grounds in an easy-to-wash, stainless steel bucket with a tight-closing lid. Be sure to use the coffee grounds on your azaleas within two days to help prevent the growth of mold and to keep gnats away.
Another great way to get a hold of used coffee grounds is from a local cafe. Whether this location is a national chain or a local coffee shop, many establishments are more than happy to give away their used coffee grounds. This saves them more room in their trash and gives the baristas one less thing to dispose of at the end of their shift.
Ask politely if you can get some of their coffee grounds, and set up a time and a date to collect them. Bring your stainless steel bucket with you and consider leaving a tip in exchange for your grounds. Secure the lid, and drive home with your spoils!
Are there certain kinds of coffee grounds that azaleas prefer?
What Kinds of Coffee Grounds Do Azaleas Prefer?
Azaleas can do well with just about any type of coffee grounds. Interestingly, light-roasted coffees tend to be higher in acid, whereas darker, fuller coffee blends tend to be slightly less so. The lighter coffee beans are often described as having a “bright,” “crisp,” or “citrusy” flavor, and this is thanks to the higher proportions of acid.
So if you’re looking to incorporate the highest levels of acid at once, choose a lighter and crisper blend for the highest levels of acid. Dark blends work, too but will acidify soil at a slightly slower rate.
Something to keep in mind is that raw, dry-ground coffee is more acidic than used coffee grounds. So if you have some ground coffee with a flavor you’re not especially fond of, you can use this on your azaleas once every other week. This is a great way to get rid of “Christmas Eggnog and Peppermint” flavored coffee while helping your azalea bushes to thrive.
Ground coffee that’s been brewed can be used on your azaleas as well, and the methods for incorporating both forms of ground coffee are the same.
How Can I Apply Coffee Grounds to my Azaleas?
There are two main ways to apply coffee grounds to azalea bushes.
The first method involves sprinkling the coffee grounds on top of your soil and then watering them into the ground. Starting at a radius of about 8 inches out from the main trunk of the shrub, spread about 2 cups of coffee grounds on top of the soil around the base of your azalea.
Next, water your azalea bush to help these coffee grounds work their way into the soil. Subsequent rains will help incorporate the grounds into the soil, as will hungry insects and worms.
The second method involves seeping used coffee grounds in water overnight and watering your azaleas with this liquid. Make sure that the holes in the head of your watering can are large enough to allow grounds to pass through.
- Add 1 cup of grounds to 1 gallon of water
- Seep the water and used grounds overnight
- Swirl vigorously before watering to loosen the coffee grounds
- Water your azalea bushes with the caffeinated water
This process is especially beneficial to growing azaleas in the early spring, right before they begin to grow and bloom. This is when acidity, nitrogen, and potassium are going to help your azalea shrub grow, bloom, and thrive.
What about the rest of the year? Can you keep fertilizing your azaleas with coffee year-round, or is this a safer process for springtime?
Can I Fertilize Azaleas with Coffee Grounds Year-Round
Whether or not you can safely treat your azaleas with coffee year-round depends upon the acidity of your soil. If your soil has a pH level of 4.5-5.0, it’s already on the edge of what an azalea can tolerate, and you shouldn’t treat your azaleas with coffee beyond an initial springtime fertilizing.
But a pH level of 5.1 to 6.0 can benefit from a coffee treatment twice a month throughout the spring and summer. Every other week is best to allow the coffee grounds to sink into the earth, decompose, and feed the azalea properly. Make sure you test the pH levels of your soil around the azalea to ensure it’s not getting too acidic.
If the soil your azalea is growing in has a pH level above 6.0, treat your azalea with coffee weekly until pH levels come down to 6.0, and then treat it with coffee grounds bi-weekly as needed. Monitor pH levels weekly to ensure that your azalea’s soil is not becoming too acidic.
Once summer begins to wind down, cease fertilizing your azaleas with coffee grounds. Giving an azalea too much coffee in autumn can confuse the shrug and cause it to grow or blossom too far into colder weather, damaging or killing the plant.
So what happens to an azalea that gets too much acid? Is this even possible, and how can you keep acid levels manageable?
Can An Azalea Get Too Many Coffee Grounds?
While azaleas thrive in acidic soil, even azaleas have their limits. Anything below a 4.5 pH level will cause your azalea bush to struggle to thrive. You’ll notice smaller leaves, smaller or fewer flowers, no flowers at all, and possibly the death of the entire shrub.
So how can you avoid giving too many coffee grounds to your azalea? The best method is to test your soil’s pH level weekly simply. This is especially important if you live in an area with naturally acidic soil. Wetter, warmer climates tend to have naturally acid-rich soil, whereas drier climates tend to be more alkaline.
Keep testing your soil weekly, and make sure to visually inspect your azalea bush, too. If you notice smaller leaves, smaller or fewer flowers, yellowing leaves, or other signs of distress, ease off on the coffee grounds for the season.
Besides treating it with coffee grounds and easing off the coffee grounds if the soil becomes too acidic, how else can you care for your azalea bush?
How Else Can I Care For My Azalea?
Azaleas do best in partial shade and will benefit from a careful trim after their blooming season is over. Prone back smaller branches lightly for a more rounded look, and keep your azalea shrub manageable and lovely next season.
Be careful if you have livestock or small children, however. Azaleas are beautiful, but their leaves and flowers can be poisonous to animals and humans. Nausea and diarrhea are the most common symptoms of azalea poisoning, especially in domesticated animals like sheep, goats, and horses. Be sure to pasture these animals far away from any azaleas.
Apart from this, azaleas are pretty hands-off. They love dappled sunlight and love water and can benefit from mulching early in the season.
This mulch is another great place to use your coffee grounds in the spring and throughout the year in your garden. Coffee grounds can greatly enrich compost and are great around the garden and yard.
Coffee Grounds Make Great Compost
One of the most beneficial uses for coffee grounds is as a part of a healthy compost heap. Azaleas also love compost, and other vegetables, flowers, and shrubs can benefit from it too.
Coffee grounds are a “green” compost item, despite their dark brown or black color. This is because they add nitrogen to the soil. Other examples of green compost items include
- Fruit rinds
- Vegetable peels
- Tea bags
- Fresh grass clippings
In contrast, “brown” compost items are typically drier and add carbon to the soil. Both are vital for healthy plant life. Examples of brown compost items include:
- Dry leaves
- Corn cobs
- Wood chips
- Paper and Cardboard
A healthy compost heap has a mixture of about 50% green and 50% brown materials. The brown compost often decays at a slower rate and helps aerate the decaying material.
Feel free to compost your azaleas early in the growing season and at the beginning of each month in spring and summer. The more coffee grounds in your compost, the happier your azaleas will be. Just be sure to test pH levels around your azalea shrub and make sure the soil is not becoming overly acidic.
This compost can be used elsewhere in your garden, especially as your vegetables and flowers are just getting started in the spring. Coffee grounds will also help encourage the presence of worms and microbes, which are vital to the health of the soil. So, apart from composting coffee grounds, what other uses can they have around the house?
Check out: Plants that don’t like coffee grounds
Can I Use Coffee Grounds Around My House?
Dry, raw coffee grounds that have not been brewed are great at absorbing odors and moisture. Put some in a smelly fridge or in a part of the house that is especially damp or musty.
Coffee grounds are also naturally abrasive and rough and make a great scrubbing agent on hard-to-clean surfaces. Use them on pots and pans. Sprinkle the grounds on dirty surfaces, soap up, and scrub as normal. Make sure to wash the grounds away when you’re done.
Coffee also makes a beautiful, light brown natural dye. Use it to dye natural fabrics as well as Easter eggs, crafts projects, and homemade paper.
Azaleas love coffee grounds due to their natural acidity. Azaleas thrive in soils with a pH level of 4.5 – 6.0 and can generally benefit from being treated with coffee grounds early in the growing season and throughout spring and summer.
The simplest ways to fertilize with coffee grounds involve sprinkling 1 -2 cups of used coffee grounds on soil about 8 inches out from the base of the azalea bush. Other methods include watering the azalea with coffee-infused water and adding coffee ground-enriched compost to your azalea plant in the early spring.
Make sure you test the pH level of your azalea’s surrounding soil and stop using coffee grounds if the pH level falls to 5.0 or below.
Other uses for coffee grounds around the home include as an absorbent solution for moisture and odor, as a scrubbing agent for pots and pans, and as a natural dye.