Use a sharp spade to cut through the rhizomes (underground root-like stems) to disconnect the hydrangeas you want to keep from those you want to remove. Continually prune the unwanted stems to ground level whenever they appear. Over time these stems should weaken and die.
If the plant is leggy when you purchased it, shear the plant back hard by 1/3 to 1/2 its original size. Once it puts on an inch or two of growth, pinch the branch tips to remove just the growing tip. This tip controls branching. Once it is removed the buds below it will turn into two or more stems.
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.
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.
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.
In addition to encouraging hydrangeas to produce more flowers, pruning these shrubs each year helps keep them healthy if they get damaged by weather and allows you to shape them however you like.
When you deadhead hydrangeas, you aren't harming the plants at all. Removing the spent blooms triggers flowering shrubs to stop producing seeds and instead put their energy toward root and foliage development. This makes plants stronger and healthier, so by deadheading, you'll be doing your hydrangeas a favor.
If you don't prune hydrangeas then they can eventually resemble a tangled mass of woody stems, and the flowers will become smaller and less showy.
Trimming should be done immediately after flowering stops in summer, but no later than August 1. Do not prune in fall, winter, or spring or you could be cutting off new buds. Tip-pruning the branches as leaves emerge in spring can encourage multiple, smaller flower heads rather than fewer larger flower heads.
In general, plants should be pruned to improve appearance not control size. I repeat that because it's important: Hydrangeas should be pruned to improve appearance, not control size. The mature hydrangea is a shrub that cannot be made smaller.
Sometimes bigleaf hydrangeas become overgrown and need to be trimmed. However, too much pruning will greatly reduce or eliminate flowering. In late summer, after the bloom period, dried flowers can be removed.
They don't form a central taproot like rhododendrons and shrubs. Instead, they grow in a loose, spreading mass of fibers often referred to as a root ball. The vast majority of a Hydrangea's roots will stay within the top six inches or so of soil. However, they do tend to spread quite a bit in the horizontal direction.
TOO MUCH SUN
Conversely, too much direct sun may stress hydrangea plants, which can force them to conserve energy by not forming flowers.
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.
If you're looking for a natural way to help your hydrangeas reach their fullest potential, then Epsom salt could be just what the doctor ordered. Not only is it a superb choice for improving soil fertility and helping your plants thrive, but it also provides essential nutrients that help combat common gardening woes.
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.
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.
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.