Skip to Content

Do Hydrangeas Like Coffee Grounds? (If YES, What Quantity?)

For roses, coffee grounds add more nitrogen to the soil and therefore making the cultivated roses look much healthier and full. But what about hydrangeas? Do hydrangeas like coffee grounds? Yes, they do!

Hydrangeas grow well without coffee grounds; however, when coffee grounds are introduced to the soil, it makes your hydrangeas produce vibrant blue flowers instead of the typical white or pink flowers.

Coffee grounds have proved to be a useful soil “supplement” that makes certain plants and flowers grow healthier, stronger, and more colorful.

There are quite many nutrients in coffee grounds, and these nutrients are really needed by plants for healthy growth.

Coffee Grounds for Hydrangeas

Mainly, coffee grounds are seen as waste – not everyone knows that coffee grounds are rich in various nutrients. The major nutrient in coffee grounds is nitrogen, and it is acidic.

Apparently, the soil also contains various minerals and micronutrients that help various plants grow.

So, when coffee grounds are added to the soil, it increases the acidity level of the soil. This increase in acidity level is what affects the cultivated plants or crops on that soil.

When you grow hydrangeas in highly acidic soil, it changes the color texture; thus, when coffee grounds are added to increase the acidity of the soil, it causes hydrangeas to change color. 

Coffee grounds are especially used by gardeners that prefer having blue-colored hydrangeas rather than other colors such as purple, pink, or white.

However, just like fertilizers, coffee grounds need to be added moderately. This is because too much acidity in the soil can kill the roots of your hydrangeas.

Do Hydrangeas Like Coffee Grounds?

Apparently, they do. There is nothing wrong with pouring out those waste coffee grounds into the soil, close to your hydrangeas.

Well, it’s not just coffee grounds, but aluminum sulfate and eggshells can also increase the acidity of the soil; hence, they can also make your hydrangeas turn blue.

One thing to keep in mind while applying coffee grounds to any plant is that you need to add a specific quantity.

For example, when you pour out too much coffee grounds on roses, it makes the leaves weak so they die off in the winter season. 

That said, adding too much coffee grounds can possibly cause any plant more harm than good.

In the case of hydrangeas, there is no known effect of adding too much coffee grounds. Regardless, it is advisable to keep the application moderate.

What Does Coffee Grounds Do To Hydrangeas?

The nutrients in coffee grounds include iron, nitrogen, phosphorus, potassium, calcium, and magnesium. All these nutrients are needed by different plants to grow well.

Apparently, asides from influencing the color of your hydrangeas flowers, there’s no other effect or change to notice.

How To Add Coffee Grounds To Hydrangeas

Do Hydrangeas Like Coffee Grounds

It is important that you know how to add coffee grounds to your plants. Actually, there are factors to consider before adding coffee grounds to your garden soil.

These factors are what to determine the exact quantity of coffee grounds you should add to the soil.

Some soils are highly acidic, naturally, for such soils, you’d need to apply very little quantity of coffee grounds and save the remaining ones for another time.

To get started, it is advisable for you to check the soil pH of your garden. Interestingly, there are intuitive at-home soil test kits that work for this purpose.

When you test the soil and notice that it has an incredibly high alkaline, you’d need a lot of coffee grounds to make it acidic.

In contrast, if your garden soil has a neutral pH rating, any amount of coffee grounds is enough to turn your hydrangeas blue.

The best way to add coffee grounds to the soil is by digging up the soil and then pour in the grounds.

Well, a lot of people do throw coffee grounds around (on top of the soil); actually, there’s nothing wrong with that; however, it’d make your garden look awkward on a closer view and it has an unpleasant smell.

More so, there’s nothing wrong with adding coffee grounds to your compost since it is also a somewhat fertilizer. You can apply them while adding fertilizer to your garden. Furthermore, you need to plan a routine for this practice.

Yes, you need to keep adding coffee grounds to your garden soil to keep its acidity levels high to ensure you get the expected result, which is blue hydrangeas flowers.

Sad as it may sound, the moment you stop adding coffee grounds regularly to keep the soil acidity high, the soil would over time get back to its natural pH level and your hydrangeas would likely return to the natural color.

But, where can you always buy or get coffee grounds?

Where To Buy/Get Coffee Grounds

You’d likely find coffee grounds in garden stores or some select stores that sell plants’ stuff. The best way to get coffee grounds is from coffee brewers.

If you frequently brew coffee at home, then you’d always have the grounds to use in your garden. 

Coffee grounds are best stored in airtight containers. Once air can penetrate the container, the grounds would thicken and become almost unusable.

Other gardeners have a special way of storing used coffee grounds; some even store them in their refrigerator. 

If you have a store where you could always buy fresh coffee grounds, it’s best to buy them when you need them. 

What More?

So, conclusively, do hydrangeas like coffee grounds? As already explained in this article, coffee grounds won’t cause any damage to your flower (hydrangeas), instead, they’d change the color profile.

If you love blue hydrangeas in gardens, then you’d need coffee grounds quite frequently – to keep your garden’s soil highly acidic always.

Roses are another plants that like coffee grounds. You can add grounds directly into the soil, toss them around (on top of the soil), or add them to your compost. Whichever, you apply coffee grounds to your garden, the effect/output is the same.

Read Also: