Hydrangea Plant Care

Jeanne Grunert
Colorful hydrangeas

Caring for a hydrangea is relatively easy as long as you plant a variety that will do well in your garden. Paying attention to this shrub's ideal planting zones, sun and water requirements is really all that's required to keep your hydrangea happy.

Hydrangea Care Guide

Keep your hydrangeas healthy by following some general guidelines for optimal blooms.

Light Requirements

Hydrangeas need full sun to partial shade. Full sun is defined as six or more hours of sunlight per day, with partial sun morning sunlight, followed by some dappled shade in the late afternoon or during the hottest part of the day. The only light conditions in which hydrangea won't do well is full, dense shade.

Soil

Hydrangeas thrive in a wide variety of soil pH conditions, which also affects the color of the blooms.

  • Alkaline soil turns the flowers pink, so add a little lime to the soil if this is the color you want.
  • More acidic soil turns the flowers shades of blue, so work some used coffee grounds into the soil around the shrub's base if this is the coloring you prefer.
  • Aluminum sulfate can also help produce blue bloom, but use it according to the directions on the label. Using too much will burn the shrub's roots.

Hydrangeas do prefer a rich, loamy soil, so work in some good, well-rotted manure or compost into the soil before planting.

Fertilizer

Beautiful hydrangea blossoms; Copyright Pippawest at Dreamstime.com

Since fertilizers may change soil pH slightly, they can also change the color of the blooms. Even a slight difference in pH may be all it takes to change a hydrangea's color even a little bit. A balanced, slow-release fertilizer, such as a 10-10-10 fertilizer, is fine for hydrangeas. Give them a little boost of fertilizer in the spring and perhaps once again in the summer, but do not fertilize after that.

Watering

Hydrangeas are slightly fussy about water.

  • Give them a good drink at least once a week.
  • Try not to let them dry out.
  • During droughts or long periods between natural rainfall, give the roots a good soak with the hose.
  • Consider installing a drip irrigation system to make it even easier to water well and often.

While hydrangeas need more water than most shrubs, they also do not like to sit in soggy soil. So, be sure to add compost prior to planting to give them the nutrient boost they need, as well as improve drainage naturally.

Planting Time

The best time to plant hydrangeas is in the spring after the threat of frost has passed. This gives the plants plenty of time to set down roots and get used to their new location without the day's heat stressing them too much. If you've missed the window of opportunity in the spring, plant them in the fall, which also provides ample time for the plants to settle in before going dormant in the wintertime.

Transplanting

If you have a hydrangea bush in the landscape but want to move it, do so before the leaves grow in the springtime. Hydrangeas set down lots of little roots and have a large root ball, so be sure to dig around the hydrangea plant and take as much soil from its original location as possible to avoid disturbing the roots. Replant the hydrangea and keep it watered well through the transition period.

Pruning

You can remove spent blooms or dead or sick branches at any time. Most hydrangeas produce flowers just fine without regular pruning, but they can be cut back if they get too big.

Pruning a hydrangea; Copyright Lianem at Dreamstime.com

Depending on which type of hydrangea you choose, it may bloom on old wood or new growth.

  • Mopheads, lacecaps and oakleaf hydrangeas bloom on old wood, so it's a good idea to prune these in the early summer (before August). They produce the stems that will make next year's blooms though the late summer and fall.
  • The paniculatas bloom on new growth, so you can prune them nearly any time you want except in the month or so before they are set to bloom.
  • If you don't know which kind of hydrangea you have, pruning in the early summer should be fine.

Mulching

Hydrangeas like moist but not soggy conditions, so a layer of mulch added around the plants helps retain moisture. Not only does mulch conserve water, it will also give your landscape a nice appearance and suppress unsightly weeds.

Winter Protection

Smaller, potted hydrangeas should be brought inside before the coldest weather sets in. If the container is too large to move easily or your hydrangea is planted in the ground, you can wrap it with some light foam insulation secured with string.

Enjoy Your Hydrangea

Hydrangeas provide showy blossoms for weeks in the spring before they fade, so enjoy them while you can. You can cut them for indoor bouquets or even dry them and keep them in year round arrangements. Even after the blooms are gone, the large dark green leaves still make hydrangeas an attractive landscape shrub during the rest of the growing season.

Hydrangea Plant Care