Mistakes Everyone Makes When Planting Hydrangeas

Beloved for their large, flowering heads and beautiful presence in garden designs, hydrangeas are a favorite choice for both new and seasoned gardeners. They serve as an elegant statement plant that can do wonders for your curb appeal. Not to mention, hydrangeas are great cutting flowers to make beautiful, colorful arrangements all over your home. What's not to love? The flowering shrub is relatively easy to grow and maintain, as long as you avoid some common mistakes everyone makes when planting them.

Maybe you purchased one excitedly from the garden center, agonized over the perfect spot to plant it, and then ... nothing — not a single bloom to reward you for all of your time and effort. If you scour any gardening blogs or discussion forums, you'll see this is a common problem that plagues many other green thumbs. Take heart that you're not alone, and then follow this checklist. There's a good chance that one of these common mistakes is to blame for your hydrangea woes. And remember, since perennials usually take three years to mature, you'll need to be patient with your new bush. The end result will be worth it, though, and once you use a bit of patience and care, your hydrangea plants will take off and look absolutely extraordinary in your yard.

Over-fertilizing

While fertilizer delivers key nutrients to plants and greatly improves their health, too much fertilizer — or over-fertilizing — can have the opposite effect and cause detrimental damage. If your hydrangeas aren't blooming, don't dump fertilizer all over them and hope for the best. You'll end up with scorched plants from fertilizer burn, tons of foliage but no blooms, or even both!

There are lots of choices for fertilizer, and it can be an overwhelming decision to have so many options in front of you. If you're looking for simplicity, Gardening Know How suggested a yearly application of a slow-release chemical that's specifically made for trees and shrubs. If you'd prefer to use an organic option instead, try a combination of peat moss, compost, and sulfur. When you're ready to apply the fertilizer, cover the area so that it surrounds the drip line — aka the space under the outer circumference of a plant's branches — and not directly at the base of your hydrangea. Once it's all spread out, water your plants.

Improper pruning

Hydrangeas are extremely temperamental when it comes to pruning. There's no "one size fits all" set of instructions for pruning them, because it varies greatly between the types. If you cut at the wrong time, you could be destroying next year's blooms, or if you cut back too much, you might stunt the growth. What's a home gardener to do?

To avoid long-term repercussions as a result of improper pruning, determine if your particular variety of hydrangea blooms on old wood or new wood. Fine Gardening noted that the only time old growth varieties should be pruned is after they stop producing flowers. Varieties that bloom on new growth, however, should either be pruned in the spring or the fall. If you prune in the spring, you can do so after the last frost, but make sure to complete your pruning before any small, green buds appear. If you see the green buds, the hydrangea is already awake and shouldn't be trimmed. If you want to prune in the fall, the plants will be dormant and at no risk for harm.

Fine Gardening offered a tip if your hydrangeas are prone to flopping — aka weight of the flowers causes the plant to collapse, especially after a heavy rainfall. If you trim the stems so that they are 18 to 24 inches high, this helps give the bush a strong enough base to hold up heavy blooms. As your hydrangea matures over the years, this base will grow stronger.

Overwatering

We know that all plants need water to survive, but if you douse your hydrangea with too much water, you're going to harm it. According to Gardening Know How, hydrangeas like moist, well-draining soil. The key here is moist, not drenched. Once you start to overwater your plants, it won't be long before the roots begin to rot. SFGATE explained that rotting roots will lead to yellowing leaves, stunted flower growth, and overall failure to thrive. A good rule of thumb is to stick your finger down into the soil at the base of the hydrangea. If the dirt is dry, go ahead and give it a nice drink of water. If the dirt is still moist, hold off on watering.

It's important to note that there is a (slight) exception to this — and that comes into play with droughts. If your area experiences a severe drought during the summer months, you'll definitely need to increase how much you're watering. Watch out for droopiness or curling, dry leaves, as these are telltale signs that the hydrangea needs a drink during a drought.

Too much sunlight

Though many hydrangea varieties can tolerate full sun, that doesn't mean they'll be happiest in such a setting. In general, the flowering shrub does best in morning sun and afternoon shade. Certain varieties can tolerate more sunlight than others, so be sure to read the care tag of your particular plant to ensure it receives the proper amount of light.

If your hydrangea is getting scorched by the sun, there are a few things you may begin to notice. Gardening Know How noted that droopy hydrangeas are usually caused by a combination of too much direct sun (this zaps the shrub's energy) and that they need more water (which helps it bounce back from the stress of the sun). Maybe yours aren't drooping, but the blooms fade quickly or never seem to reach their full potential. HGTV warned that too much sunshine is usually the cause of faded, lackluster blooms.

Your best solution would be to transplant the hydrangeas to a shadier location once they're dormant, but if that's not an option, you'll need to be more diligent with more frequent watering. Additionally, HGTV suggested adding a layer of mulch around the base of the shrub to help retain some of the moisture.

Poor plant placement

With the exception of dwarf varieties, hydrangeas need space to expand as they mature and get bigger. The plant might not look like much when you bring it home from the garden center in its gallon-sized pot, but just give it a few years. According to Hyannis Country Garden, the Nikko Blue hydrangea, for example, can grow to an astounding size of eight feet wide and six feet tall. If you didn't plan accordingly when you did your garden layout and plant placement, your hydrangeas may start crowding each other or the plants around them. When this happens, they won't be able to bloom to their full potential. By planting in a poor location, you may be forced to prune excessively in an attempt to combat the overcrowding.

Another problem? Planting in an area that has too much shade and not enough sunlight, as per DIY Network. You'll likely end up with a hydrangea that's heavily-leafy but produces very few flowers. Instead, do a little research before you start digging. This will ensure proper spacing that can accommodate the growth of your hydrangeas in the coming years, as well as guarantees the proper balance of sunshine and shade. A small amount work up front will save you tons of work in the long run.