Hydrangea Care Guide
By Richard "Woodie" Buller, GGD co-founder with 35+ years in horticulture
Published On: Aug 14, 2020
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Most of the hydrangea questions I hear start the same way: "Why didn't my hydrangea bloom this year?" Nine times out of ten, nothing is wrong with the plant. It was simply cared for like a different kind of hydrangea.
That's the thing about hydrangeas. The name covers five main types that show up in our gardens, from sun-loving panicles to a vine that climbs shady walls. They all like moist, well-drained soil, but they disagree on sun, pruning, and even flower color.
The good news? Once you know which one you're growing, care gets simple. Start here to identify your hydrangea and learn the basics they all share, then jump to the full guide for your type.
| In this Article | |||
|---|---|---|---|
Which Type of Hydrangea Do You Have?
Look at the flowers and leaves first. Here is how the five main types compare.
| Type | Flowers | Light | Blooms On | When to Prune | Full Guide |
|---|---|---|---|---|---|
| Bigleaf (Hydrangea macrophylla) | Round mopheads or flat lacecaps in blue, pink, purple, or white | Morning sun, afternoon shade | Old wood (rebloomers also on new) | Right after flowering, by early August | Bigleaf Hydrangea Care Guide |
| Panicle (Hydrangea paniculata) | Cone-shaped clusters, white or lime aging to pink | Full sun to part shade | New wood | Late winter to early spring | Panicle Hydrangea Care Guide |
| Smooth (Hydrangea arborescens) | Large round heads in white, lime, or pink | Part shade, or sun with steady water | New wood | Late winter to early spring | Smooth Hydrangea Care Guide |
| Oakleaf (Hydrangea quercifolia) | White cones over large oak-shaped leaves | Part shade | Old wood | Right after flowering | Shop oakleaf hydrangeas |
| Climbing (Hydrangea anomala subsp. petiolaris) | Flat white lacecaps on a clinging vine | Shade to part shade | Old wood | Lightly, right after flowering | Climbing Hydrangea Care Guide |
Bigleaf Hydrangeas: The Classic Blue and Pink Blooms
These are the hydrangeas most people picture: big mophead blooms or flat lacecaps in blue, pink, and purple. They are also the only common type whose flower color shifts with your soil. Rebloomers like the Endless Summer® Reblooming Hydrangea set buds on both old and new stems, so a hard winter or an untimely pruning won't cost you the whole season.
Read the full Bigleaf Hydrangea Care Guide, or shop bigleaf hydrangeas.
Panicle Hydrangeas: The Toughest of the Bunch
If you have a sunny yard, start here. Panicle hydrangeas handle more sun and more cold than any other type, and because they bloom on new growth, they flower reliably every summer. The Limelight Hydrangea and Bobo® Hydrangea are two of our most popular for good reason. Their cone-shaped blooms open white or lime and blush pink as the nights cool.
Read the full Panicle Hydrangea Care Guide, or shop panicle hydrangeas.
Smooth Hydrangeas: The Native Workhorse
Smooth hydrangeas are native to the eastern U.S., and they are about as forgiving as hydrangeas get. They bloom on new wood, so you can cut them back in late winter and still count on big summer flowers. Newer varieties like the Incrediball® Hydrangea were bred with sturdier stems that hold those heavy blooms upright after a summer storm.
Read the full Smooth Hydrangea Care Guide, or shop smooth hydrangeas.
Oakleaf Hydrangeas: Interest in Every Season
Oakleaf hydrangeas are native to the Southeast and earn their space all year: white flower cones in early summer, rich burgundy fall color, and peeling cinnamon bark in winter. They bloom on old wood, so prune only right after flowering, if at all. The Snow Queen Oakleaf Hydrangea is a classic, and the Munchkin Oakleaf Hydrangea fits smaller beds.
Climbing Hydrangeas: The Shade-Loving Vine
Climbing Hydrangea clings to brick, stone, and tree trunks with small aerial roots and covers a shady wall with white lacecap blooms in early summer. Be patient with it. It usually takes a few years to settle in before it starts climbing in earnest.
Read the full Climbing Hydrangea Care Guide.
Woodie's take: If you're new to hydrangeas or you have a sunny spot, start with a panicle. It's the hardest one to get wrong.
How Much Sun Do Hydrangeas Need?
It depends on the type, but a safe rule for most hydrangeas is morning sun and afternoon shade. Morning light fuels the blooms, and afternoon shade keeps the leaves from scorching in the hottest part of the day.
- Panicle: full sun to part shade. Give it at least 6 hours of sun for the best blooms.
- Smooth and oakleaf: part shade. Both take more sun in cooler regions if the soil stays moist.
- Bigleaf: morning sun and afternoon shade, especially in the South.
- Climbing: shade to part shade. A north- or east-facing wall works well.
Too much shade is one of the most common reasons a hydrangea grows plenty of leaves but very few flowers.
How Often Should I Water Hydrangeas?
Hydrangeas are thirsty shrubs. The name even comes from the Greek words for water and vessel. Aim for about an inch of water a week, more during hot, dry stretches and all through the first year after planting.
Water deeply at the base in the morning, and let the top inch or two of soil dry slightly between waterings. Soil that stays soggy invites root rot.
Don't panic if the leaves droop on a hot afternoon. Bigleaf and smooth hydrangeas often wilt in midday heat and perk back up by evening. Check the soil before you water. If it's still moist a couple of inches down, wait.
A 2 to 3 inch layer of mulch keeps roots cool and holds moisture. Keep it a few inches away from the stems.
When Should I Prune My Hydrangea?
This is the question that matters most, and the answer depends on whether your hydrangea blooms on old wood or new wood.
Old wood means the flower buds form on last year's stems, in late summer and fall. Prune these right after they finish blooming in summer. Cut them in fall, winter, or spring and you'll remove next year's flowers. This group includes bigleaf, oakleaf, and climbing hydrangeas.
New wood means the blooms form on this year's growth. Prune these in late winter or early spring, before new growth starts. This group includes panicle and smooth hydrangeas.
Not sure which one you have? Just remove dead stems in spring and leave the rest. You can't go wrong with that.
Why Isn't My Hydrangea Blooming?
Nine times out of ten, it's one of these:
- Pruned at the wrong time. This is the big one for bigleaf, oakleaf, and climbing hydrangeas.
- Winter damage or a late frost. Bigleaf flower buds can die back in colder zones even when the plant survives.
- Too much shade. Leaves grow fine in shade, but flowers need some sun.
- Too much nitrogen. Lawn fertilizer that drifts into the bed pushes leaves instead of blooms.
- A young or recently moved plant. Give it a season or two to settle in.
If a bigleaf keeps skipping bloom in a cold area, try a reblooming variety, or switch to a panicle or smooth hydrangea that blooms on new wood.
Can I Change the Color of My Hydrangea?
Only some of them. Pink and blue bigleaf hydrangeas change color with soil pH. White hydrangeas stay white, and panicle, smooth, and oakleaf types don't change with your soil. (Panicle blooms do blush pink as they age, but that happens no matter what your soil is like.)
- For blue: acidic soil, around pH 5.5 or lower. A soil acidifier or aluminum sulfate makes the aluminum in your soil available to the plant, and that is what turns the blooms blue.
- For pink: neutral to alkaline soil, around pH 6.5 or higher. Garden lime raises pH.
Color shifts slowly, usually over a season or two. Test your soil first, adjust a little at a time, and follow the directions on whatever product you use. If you want guaranteed blue in alkaline soil, growing a bigleaf in a container is the easiest way to control it.
For more on lowering pH, see our guide on how to acidify soil for acid-loving plants.
How Do I Fertilize Hydrangeas?
Hydrangeas don't need much. Feed once in spring as new growth starts with a slow-release, balanced shrub fertilizer. Reblooming bigleaf types can take a second light feeding in early summer.
Stop feeding by August so the plant can harden off before winter. And go easy on nitrogen: too much gives you a big, leafy shrub with very few flowers.
When Is the Best Time to Plant Hydrangeas?
Fall and spring. Fall is my favorite. Warm soil and cool air let the roots settle in before summer heat arrives. Aim to plant at least six weeks before your first hard frost.
Spring planting works well too. Just stay on top of watering through that first summer.
How Do I Plant a Hydrangea?
- Pick the right spot. Match the location to your type: light, space, and mature size.
- Dig a wide hole. Make it twice as wide as the root ball and no deeper.
- Set the plant. Loosen any circling roots and set the plant so the top of the root ball sits level with the soil or slightly above it.
- Backfill. Fill in with your native soil mixed with a little compost. Woodie's Root Booster helps new roots get established faster.
- Water and mulch. Water deeply, then spread 2 to 3 inches of mulch, keeping it a few inches off the stems.
Are Hydrangeas Toxic to Pets?
Yes, mildly. According to the ASPCA, hydrangea leaves, buds, and flowers can upset the stomach of dogs, cats, and horses if eaten. Serious poisoning is rare and usually takes a fair amount of plant, but it's smart to keep hydrangeas away from pets that like to chew.
Woodie's Take
Hydrangeas have a reputation for being fussy. I don't think they are. They just ask you to know which one you planted.
Get the type right, give it the light it likes, water deeply, and prune at the right time. Do that, and a hydrangea will bloom faithfully for decades. Few shrubs give back as much for so little.
Find your type in the chart above, and the full guide will walk you through the rest.