If you're growing hydrangeas, use coffee grounds to affect their color. Coffee grounds add extra acidity to the soil around hydrangeas. On a chemical level, this increased acidity makes it easier for the plant to absorb naturally occurring aluminum in the dirt. The effect is pretty blue clusters of flowers.
Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum. In addition, fruit peels, lawn clippings, peat moss and pine needles, are thought to have a similar effect.
Most hydrangeas prefer partial sun with full sun in the morning, followed by some afternoon shade. This is especially true for the Bigleaf hydrangea (H. macrophylla). Some varieties are more tolerant of full sun. Most hydrangeas will thrive in fertile, well-draining soils that receive plenty of moisture.
It's best to start adding coffee grounds to the soil months before the blooming season begins, ideally in the late fall. You can repeat the process with your typical fertilizing schedule. With a little caffeine and a lot of patience, your hydrangeas should reward your efforts come spring with the boldest blue globes.
If your soil is more alkaline, your hydrangeas will be pink or even purple. According to Garden Design, adding lime or eggshells to the soil will ensure a pinker color, while adding aluminum sulfate, pine needles, or coffee grounds can give your hydrangeas the blues.
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.
Hydrangea Care Tips
Water at a rate of 1 inch per week throughout the growing season. Deeply water 3 times a week to encourage root growth. Bigleaf and smooth hydrangeas require more water, but all varieties benefit from consistent moisture.
Best Fertilizer For Hydrangeas
Organic, slow-release fertilizers for roses (such as a 15-10-10, or 10-5-5 formula) work well on hydrangeas, giving the plants the nutrients they need to increase the size and quantity of their blooms.
Miracle-Gro Performance Organics Blooms Nutrition
This is an all-purpose blossom booster that's suitable for use on a wide variety of perennial and annual blooming plants, including hydrangeas. It provides various minerals, including copper, calcium, and iron, to supplement common nutrient deficiencies.
You can use vinegar to lower the pH of your soil, but be aware that in order to achieve blue blooms, you will need both an acidic environment and aluminum ions. The acidic environment will also need to be a sustained over a period of time, which could be hard if rainwater is washing the vinegar away.
Though hydrangeas prefer protection from hot direct sun, too much shade can prevent them from forming flower buds. Ideal light conditions for hydrangeas are several hours of direct morning sun with afternoon shade, or dappled shade that allows plenty of bright indirect light.
How Often Should You Add Coffee Grounds to Plants? You can fertilize houseplants an average of 7 to 10 days in a row, but no more, as there is a risk of over-acidification of the soil. A cup of ground coffee should be added to the compost once a week.
First, add a 1/4 cup of sugar to the room temperature water in the vase. The sugar helps feed the stems and increases the life of the cut flowers.
Hydrangeas produce a “sap” that clogs their stems and blocks water from traveling up it to those gorgeous blooms. The boiling water helps to do away with the sap.
Homemade compost is a great source of slow release nutrients for hydrangeas. Either top dress the soil beneath your plants with your compost and water well or brew up a batch of compost tea and give your plants a deep drink of it. You can repeat your application of compost tea in 2 to 3 weeks.
This common household item is surprisingly effective at helping perk up plants and brighten blooms. For hydrangeas specifically, adding baking soda helps the plant retain more moisture in the roots. When this happens, the result is bigger blooms with more vibrant colors that last longer than they would otherwise.
Hydrangeas that bloom on new wood can be safely pruned in late fall once the plants have gone dormant or in early spring. Next year's flower buds won't be formed until late spring the same year they bloom, so there is no risk of removing the buds if you prune in fall or spring.
Most common hydrangeas prefer a partial sun location - ideally receiving sun in the morning hours and shade in the afternoon. The reblooming Endless Summer® Hydrangea series prefers part shade.
Keep good air space between the plants; don't crowd them together or against other plants. Don't give bigleaf hydrangeas too much love; if they're too comfortable (water, fertilizer, etc.), they may devote all their foliage to leaves instead of blooms.
But there's one key aspect of ensuring hydrangeas return bigger and better every year: deadheading. The practice of removing spent flowers from a plant, deadheading encourages stronger, more bountiful blooms later on.
Since coffee grounds have such a pungent and intense smell, mosquitoes do not like to come near it. Mosquitoes are repulsed by all types of coffee, whether it is fresh, used, or burnt. The most effective way to use coffee grounds for mosquito control is by burning them, as it creates a stronger aroma.
"It's fine to use coffee as a fertilizer," our senior lab testing technician, Jonathan Chan, says. "However, you should be careful because coffee can raise the acidity of the soil. Caffeine also is known to have a negative effect on plant growth."
As it turns out, squirrels hate coffee grounds! What is this? However, coffee grounds alone may not be enough, and you may have to call for additional help from a local pest removal company. So to answer "do coffee grounds keep squirrels away?" the answer is yes.