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Hydrangeas are classic and timeless woody flowering shrubs with beautiful round blossoms that evoke summer memories. They are considered as popular ornamental plants because of their large flowerheads and vibrant colors.

This garden flower with show appeal is a mostly carefree plant when grown under the right conditions. Most species of hydrangeas are in shades of white. However, some species can be in other eye-catching colors such as red, pink, light purple, dark purple to blue depending on soil acidity.

Here is the question, do coffee grounds help hydrangeas? To put it simply, yes, coffee grounds can help these flowering shrubs. Not only will they make them healthier, you can even change the color of your hydrangeas simply by introducing that coffee to the shrub by changing its pH level.

In What Way Does Coffee Grounds Affect Hydrangeas?

First off, before we discuss how coffee grounds affect your flowering shrub, we should first ask what does coffee grounds have to do with caring for plants? Coffee grounds are just kitchen refuse right? For starters, the strong smelling coffee deters insects, slugs and ants which are very bad for your flowers. What’s more, they are also perfect for discouraging cats from disturbing, or worse, digging in your flowerbeds. Because of this reason alone, it would be worth checking your coffee makers and collecting these. Maybe its time to pile it up around your favorite plants.

Used coffee grounds can certainly improve the quality of the soil because they are beneficial to earthworms. Due to the high nitrogen content, coffee grounds help the leaf, stem and root development. Nitrogen also helps in the composting process.

Coffee grounds contain high acidity levels. When used coffee grounds are poured over the soil, it raises the pH level. The raised pH level and increased acidity nourishes the plant and as a result, hydrangeas can more easily absorb aluminum from the soil. Once aluminum is absorbed, some species of hydrangea produces blue tinge blooms. White flower hydrangeas cannot be changed or shifted.

However, the mop head, lacecap or paniculata varieties do well in this kind of color manipulation. This way, pinker blossoms can turn into various hues of blue or purple. The color change happens because of the aluminum ions present in the acidic soil.

Can I Control What Color My Hydrangeas Will Turn To?

Since coffee grounds can help alter the acidity level of the soil, one can certainly control the amount of grounds one can use to dial up acidity or even the alkalinity of the soil. We have established that high acidity can turn pink blooms to blue.

The good news is, it also works the other way. Blue blooms can be altered to pink by dialing down the amount of coffee grounds you use. By adjusting and finding the sweet spot, you can have a little bit of say on what shade your hydrangea blooms will turn out to be.

Investing in a soil testing kit with a pH meter can be quite handy in order for you to reach your desired color outcome. Adjust the amount of grounds in order to influence the alkalinity and acidity of the soil.

How Can I Go About Adding the Coffee Grounds?

Incorporate the coffee grounds by digging it into the soil just like you would a fertilizer. Some also swore on just simply layering the coffee grounds on the top soil but this method may result in an unpleasant pile of mold that smells. Adding them to compost may also work.

Can I Just Add Any Kind of Coffee?

Interestingly, any coffee lying around will work to manipulate the acidity of your soil. Hydrangea blooms respond best to soil that is fertile, moist and regularly acidic, thus, you will have to practice adding coffee grounds in a regular basis.

Coffee grounds, used or not can be utilized but perhaps the best way to change the soil composition in the long term is to add the grounds to the fertilizer through your compost bin first.

How Much Coffee Grounds Should I Add?

Everything should be done in moderation. The same can be observed in adding coffee grounds to your hydrangeas. Yes you can manipulate the acidity level by adding more or less, however, do not go overboard with it. Excess grounds can also lead to excess nitrogen which can cause problems in the plant development.

It may also lead to the opposite of nourishing your plants and attract pests and insects instead. Too much moisture in the soil may not be good for young hydrangeas.

Clearly, coffee grounds are a versatile addition to the soil of hydrangeas both in composted or raw form. They provide a host of benefits and most importantly, they can change the color of the blooms.