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How Do Coffee Grounds Help Hydrangeas?

Do you love growing flowers? Hydrangeas are a good option. Their colorful purple, white, pink, or blue globular blooms can brighten any garden.

coffee grounds for hydrangeas

Some popular types of Hydrangeas are French Hydrangeas and Mophead Hydrangeas. They pop up during late spring and early summer.

The color of Hydrangea blooms is determined by the pH of the soil in which you plant them.

They produce striking blue blooms in soil with a pH of less than six and pinkish flowers in soils with a pH greater than seven.

It’s common for organic flower growers to fertilize their hydrangeas with organic manure made of kitchen garden remains.

Recently, people have discovered the benefits of using coffee grounds in flower and vegetable gardens. And the trend is slowly catching on.

Here is some information on growing Hydrangeas using coffee grounds.


Why You Should Use Coffee Grounds to Grow Hydrangeas

Coffee grounds increase soil acidity, providing the flowers with key minerals that boost their growth. They also retain moisture in garden soils, reducing the times you have to water your plants.

Some people use coffee grounds to attract worms to their soils which aerate and improve soil quality. But what do Hydrangeas get from coffee grounds?

Hydrangeas love acidic soil and nitrogen, two things they get from coffee grounds.

The nitrogen improves their root, stem, and leaf development while increasing their acidity, which aids in the healthy growth of flowers.

When you apply coffee grounds to your garden soil, you will notice Hydrangeas popping out flowers of different colors, especially blue or lavender ones.

You should test your soil’s pH before you add coffee grounds to it to boost the growth of your hydrangeas.


How to Test the pH of Garden Soil the DIY Way

There are some pH testing kits in gardening supplies stores that you can use to test soil pH.

If that is not an option, use a homemade solution to find out the pH of your soil. Here is an example.

  • Collect two containers of the soil in which you plan to grow Hydrangeas.
  • Add some water to the soil in both containers.
  • Pour baking soda into one soil container and vinegar into the other.
  • If the soil with vinegar fizzes, it shows you that it’s alkaline.
  • And if the soil with baking soda fizzes, it shows you the soil is acidic.
  • If both containers do not fizz, the soil has a neutral pH.

Hydrangeas thrive in acidic soil. If your soil test reveals your garden soil is acidic, you don’t need to amend it using coffee grounds.

But if it’s alkaline, and you need to grow plants like Hydrangeas that thrive in acidic soil, use coffee grounds to fertilize it.


How to Use Coffee Grounds to Grow Colorful Hydrangeas

The best way to add coffee grounds to the soil in which you are growing Hydrangeas is by layering it sparingly on top of the soil.

You can also add the coffee grounds to your garden compost. That will give the Hydrangeas additional nutrition for their growth from the other ingredients in the compost, such as egg shells and vegetable peels.

It’s important to minimize the coffee grounds you use to fertilize Hydrangeas. Too much will over-acidify your soil, burning the roots of the flowers.

Also, reduce the number of times you spread coffee grounds over your flower beds. Twice or three times a year is enough.

The best time to start fertilizing your Hydrangea garden with coffee grounds is in late fall.

Hydrangeas absorb the nutrients from coffee grounds and any other soil fertilizer slowly. You must be patient to see results. The earlier in the season you add coffee grounds to your Hydrangea garden, the faster you will notice their effect.

Avoid over-fertilizing your soil with coffee grounds. It will attract pests, interfere with the soil pH, and keep your flowers from developing properly.

Make sure you regularly check the acidity of your soil to keep it at an ideal pH for your Hydrangeas to thrive.

You may start checking for the positive effects of coffee grounds on your flowers after fertilizing them in late Summer or early Fall.

Some of the improvements to look for are bigger and more colorful blooms. You may also find some of your hydrangeas changing their color from white/pink to blue – lavender.


How Do You Change the Color of Hydrangeas Using Coffee Grounds

Hydrangeas are usually pink, white, or ivory in color. You can change the color of pink Hydrangeas to blue by adding coffee grounds to the garden soil. Wouldn’t that be an interesting sight?

If you want to try changing the color of the blooms on your Hydrangeas, choose a variety whose flowers can change color.

Oakleaf Hydrangeas, Peegee Hydrangeas, and Annabelle Hydrangeas do not change the color of their blooms no matter how you fertilize them. They always remain ivory or white in color.

But Hydrangeas such as Lacecaps, Mopheads, and French Hydrangeas can change color to blue if you grow them in the right environment and use coffee grounds to fertilize them.

It’s also interesting to note that you can change blue-colored Hydrangeas to Pink by lowering the acidity of your soil. That will require you to stop using coffee grounds on them and choose alkalizing fertilizers.

You can make a fun hobby out of playing with the color of Hydrangeas in your garden in this way.

If you find the sweet spot, you could have different colored flowers from the same Hydrangeas every year.



Are you interested in growing Hydrangeas in your flower garden? That’s information on how to use coffee grounds to encourage them to produce colorful and bigger blooms. You can also use them to change the colors of certain Hydrangeas.

Coffee grounds are also an excellent soil amendment option to use whenever you want to improve the quality of your soil.

Note that coffee grounds are only good for Hydrangeas if you grow them in a garden, not a pot. That’s because they can encourage the growth of fungi and bacteria in the pot.

If you insist on applying coffee grounds to your potted Hydrangeas, use composted grounds to avoid negative results.

Other flowers that respond well to coffee grounds are Rhododendrons and Azaleas.


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