Some gardeners swear by coffee grounds as a method for turning hydrangeas blue. Coffee grounds can increase soil acidity and result in bluer hydrangeas, but research has shown the effect can be short-lived.
I always dump my used coffee grounds on the soil below my hydrangeas...and when done regularly several months prior to blooming, the shrub is bursting with the deepest blue hydrangeas I've ever seen! The trick is to be consistent and do this as much as possible from fall through spring BEFORE they bloom.
To turn hydrangeas blue, you'll need to make your soil more acidic. You may have heard of tricks like adding coffee grounds, vinegar or even pennies or a bundle of rusty nails to the soil. However, it's best to use aluminum sulfate, which is a proven method for changing flower color.
In most cases, the grounds are too acidic to be used directly on soil, even for acid-loving plants like blueberries, azaleas and hollies. Coffee grounds inhibit the growth of some plants, including geranium, asparagus fern, Chinese mustard and Italian ryegrass.
How can you create conditions for blue blooms? Here's an answer: Aluminum sulphate. Mix with water and apply it to the soil around the plant once or twice at intervals, according to directions on the bag.
Yes, apple cider vinegar can help turn hydrangeas blue by lowering the soil pH when applied. Like white vinegar, it should be used carefully to avoid excessive acidity that could harm the plant.
Soil pH below 6.5 = Blue. Soil pH above 7.5 = Pink/purple. Soil pH 6.5 to 7.5 (neutral) = Purple, or both blue & pink. To make sepals bluer, add aluminum sulfate to soil and maintain low levels of phosphorous, moderate levels of nitrogen, and high levels of potassium.
Salts: Coffee grounds can contain salts, which can build up in the soil over time and become toxic to plants. Mold: Wet coffee grounds can attract mold, which can be harmful to plants. Caffeine: While caffeine is not toxic to plants in small quantities, it can be harmful if used in large amounts.
Coffee grounds can most certainly be added to your compost and also directly to your soil. Instead of simply tossing them out though, you may wish to incorporate them a bit more thoroughly by digging them in.
Caring for hosta plants doesn't require much effort since they're low maintenance, but planting these around your space will produce the most beautiful leaves if they're kept in moist, fertile soil. Your spent coffee grounds can help provide nutrients and create the soil environment they need.
An easy way to affect the color or your hydrangea blooms 💗💜💙 Egg shells = pink & coffee grounds = blue! The magic is all in the pH of your soil 🪴
The easiest way to acidify your soil and turn those babies blue is with aluminum sulfate, which can be found at almost any garden center. Mix ¼ oz aluminum sulfate with a gallon of water and soak the soil surrounding your hydrangeas in the spring, as soon as the plant begins to grow.
Generally speaking, acidic soil, with a pH lower than 6.0, yields blue or lavender-blue hydrangea blooms. Alkaline soil, with a pH above 7.0, promotes pinks and reds. With a pH between 6 and 7, the blooms turn purple or bluish-pink. To lower your pH, add garden sulfur or aluminum sulfate to your soil.
Well, for a quick, cheap and easy fix, you just need apple cider vinegar! Mix one cup of apple cider vinegar with 10 litres of water (an average watering can's worth) and direct the solution at the base of the hydrangea, avoiding the leaves. Do this every couple of weeks and the colour will gradually change.
Vegetable plants: Coffee grounds are also great for vegetable plants, as they help to provide a nutrient-rich soil that can produce healthy and bountiful crops. Flowers: Coffee grounds can be used to fertilize a wide variety of flowering plants, such as roses, hydrangeas, and petunias.
Cover the soil around the plant's trunk with well-dried coffee grounds and water abundantly. Each watering will release nitrogen from the coffee grits and penetrate into the soil with water, soaking the plant's root system, thereby strengthening it and protecting it from pests.
If you've been trying to get your hydrangeas to become big and blue, then we might just have the tip for you. Hydrangeas color is based on how acidic your soil is—the more acidic the soil you plant your hydrangeas in, the more blue. We've found that adding a few coffee grounds to your soil can do just the trick.
The eggshells provide calcium, potassium and magnesium, which are essential for healthy plant growth! Natural pest deterrent – The sharp edges of the eggshells also act as a natural pest deterrent, helping keep critters away from your plants and protecting the roots.
Which plants benefit from used coffee grounds? Coffee tends to be slightly acidic and is therefore good for acid-loving plants such as hydrangeas, as well as nutrient-hungry plants like roses, but again use it only in moderation on any one plant.
For example, avoid adding any caffeine to plants that are germinating. Freshly seeded areas should be avoided as well. Fresh grounds, and caffeine in general, have allelopathic properties. This can stunt plant growth and do more harm than good.
The issue with coffee grounds is that even though they are rich in nitrogen, they are high in acidity and caffeine. Thus, some recommend them only as an additive to soil for acid friendly plants (ex: blueberries, holly, azaleas, Japanese iris).
Use a fertilizer low in phosphorous (the middle number in the content analysis) such as 12‐4‐8 to encourage production of blue flowers. For other types of hydrangeas, use a general purpose fertilizer, at recommended rates on the package. Incorporate dry fertilizer into top 2” – 3” of soil and water thoroughly.
How long does it take to change hydrangea color? It can take weeks or even months to years to adjust the soil pH and therefore adjust the color of your hydrangea plants. So, it takes careful planning and patience.
Aluminum and sulfate work together to lower the soil pH, further facilitating the absorption of aluminum by the plant. By creating a more acidic environment, you'll encourage brilliant blue booms on your hydrangeas. To turn your hydrangeas pink, however, aluminum is not the answer.