7 Mistakes That Are Keeping Your Hydrangeas From Thriving

Hydrangeas are relatively low-maintenance additions to your landscaping—which is why they’re among the most popular garden plants in the U.S. But a few common mistakes in your hydrangea care could lead to wilting, a failure to bloom, or just stunted growth in general.

Ensure that your hydrangea plant will thrive for years to come by avoiding these common pitfalls.

Messing up the Light Situation

Hydrangeas thrive in partial shade, especially if they’re protected from the afternoon sun. Certain varieties—like panicle hydrangea—can deal with deep shade, but too much sun is a no-no for most hydrangea plants. You’ll especially want to avoid west-facing spots, which provide little protection from the sun’s harshest rays.

Pruning at the Wrong Time

Hydrangeas don’t generally need a lot of pruning, but doing it at the wrong time can be disastrous for your plant’s blooming. Pruning your hydrangea too late in spring is one of the biggest hydrangea mistakes. “The plant has set the buds for spring, and pruning can lead to fewer flowers,” says Megan McConnell, plant information director at Monrovia.

In fact, only “new wood” bloomers, like panicle hydrangea and smooth hydrangea, are potential candidates for pruning. “New wood bloomers should be pruned in the late fall after they’ve gone dormant, or early in the spring, before the new flower buds form,” Lenhart says.

For other, “old wood” varieties, it’s best to be incredibly conservative about pruning, if you do it at all. “It can be tricky to prune old wood blooming hydrangeas,” says Kevin Lenhart, design director for Yardzen. “Old wood bloomers should be pruned immediately after they finish flowering. Because old wood hydrangeas often bloom late into the year, there can be little post-bloom time left for pruning before the plant enters winter dormancy.” If you miss that very short window after blooming, Lenhart recommends waiting until the branches start budding, and only cutting away branches that look dead.

Planting Hydrangeas Near Plants That Damage Them

Some plants, including black walnut trees, sunflowers, goldenrod, and forsythia, release chemicals into the soil that can stunt the growth of anything planted nearby. They’ll definitely impact your hydrangea’s ability to thrive.

Watering All Wrong

As a less-fussy garden plant, hydrangea can deal with some variation in their watering, but ideally need about an inch of water per week, either through rain or your own watering. But you want to ensure that the water doesn’t stagnate around your hydrangea. “Good drainage is a must—poor drainage will quickly lead to problems for hydrangeas,” Lenhart says. Soggy soil could lead to root rot and the death of your hydrangea. And of course, too little could lead to wilting (and eventually, dying) leaves and flowers.

Overcrowding Your Hydrangeas

Do a little research on your hydrangea variety to see how large they can get, and make sure to leave enough space in the landscaping for it to reach its full size. Planting them too close together can make it harder for your hydrangea to get the nutrients it needs, and put it at increased risk of disease. (If you don’t like the gaps while you’re waiting for your hydrangea to fill in, consider planting annuals to brighten up the spaces.)

Not Amending the Soil Properly

Hydrangea can deal with a bit of variation in the soil, though a rich, loamy mix is ideal for your plant to thrive. “One mistake is only amending the backfill,” McConnell says. “Hydrangeas like rich soil. If you need to amend, you should do it to a larger area than just the hole you dug so the roots can happily spread.”

Failing to Protect Your Hydrangea for the Winter

If you live in an area with freezing cold winters, you’ll want to protect your hydrangeas for their winter slumber. Give them a good, deep watering before the last freeze, then cover their root zone in a healthy layer of compost and mulch, Lenhart says. If your hydrangeas are planted in containers, you may need to move them to a cool spot indoors. “Hydrangeas in containers have less soil volume to insulate their roots and get colder much more quickly than plants in the ground. To avoid cold damage, shift containers indoors to garages or basements, or situate pots in sheltered areas, safe from chilling winds.”