How to Grow Hydrangeas in Pots

A Guide to growing beautiful and healthy hydrangeas in pots

By Hannah Miller at DIY Gardening

Hydrangeas can really pack a punch in any garden with their large, distinctive blooms that often last from mid-summer all the way into early autumn.

Generally easy to grow and pest-resistant, hydrangeas are tolerant shrubs that will reward you with magnificent flowers each year.

But can hydrangeas be grown in pots?

They certainly can, and on this page, we’ll show how to grow a healthy, stunning hydrangea in a pot.

Hydrangea mophead

The Best Hydrangeas For Pots

You can grow almost any hydrangea in a pot, but you may wish to consider one of the dwarf varieties that only grow up to 1 metre.

The most popular hydrangeas for medium-sized pots are:

  • Hydrangea macrophylla little pink/white – a mophead that reaches 0.6 metres.
  • Hydrangea switch ophelia – a paniculata that grows no more than 0.5 metres.
  • Hydrangea macrophylla selma – a compact shrub that will eventually reach 1 metre in height.
  • Hydrangea paniculata early sensation – an early flowering variety that will reach up to 1.5 metres but can be aggressively pruned to keep it compact.

Climbers such as the hydrangea anomala petiolaris can be grown in large containers but are unlikely to reach their full potential of 12+ metres unless relocated to the ground.

Choosing a Suitable Pot

If you plan on growing a tall hydrangea, consider a heavier pot so it won’t topple over in the wind.

As a general rule of thumb, shop-purchased hydrangeas should be potted up as soon as possible for two reasons:

  • Hydrangeas need moist soil and small pots dry out much quicker than larger ones.
  • The roots of these shrubs grow quickly, and a root-bound hydrangea will be more prone to winter frost damage.

Climbers and large hydrangeas should be grown in large pots at least 0.75 metres wide.

Medium-sized hydrangeas that grow up to 1 metre high can be placed in pots around 0.5 metres wide.

Dwarf hydrangeas can be grown in smaller pots, but you may need to relocate them to a garage or shed for frost protection during the winter.

While hydrangeas are thirsty plants, they should never sit in waterlogged soil, so pots must have drainage holes and ideally be lifted off the ground in winter.

The Best Location For Potted Hydrangeas

Climbing Hydrangeas

These can be grown along fences, up walls and even around the trunks of trees. These climbers thrive in shaded areas so are best suited to north and east-facing gardens and they may struggle in waterlogged or chalky soils but are otherwise easy to grow.

Hydrangea anomala is the most popular climber and can reach 12 metres in height with a spread of over 4 metres. A slow starter, this hydrangea has the potential to grow up to 1 metre per year given the right conditions, making it perfect for covering walls in shaded areas.

Shrubby Hydrangeas

Almost every other hydrangea will require a brighter spot, and many can cope with full sun although for optimal results, they should be given some protection from midday sun when it’s at its strongest. Potted hydrangeas are more susceptible to damage from weather extremes, so we recommend a location that provides a least a little respite from the midday sun in the summer.

Watering and Fertiliser

Needless to say, hydrangeas are thirsty plants that don’t respond well to long periods in dry soil; however, the pots should have adequate drainage as no hydrangea likes sitting in waterlogged soil, which can lead to disease and leaf chlorosis (yellowing of the leaves).

During the summer, they may require a good soaking once a week and up to once a day during extreme heatwave conditions.

Hydrangeas require very little fertiliser, and too much can cause them to grow leggy with plenty of leaves and few flowers. Apply a specialist hydrangea fertiliser once a year in late spring with an optional second application in late summer, there’s no need to apply more than this.

The compost at the top of the pot can also be refreshed with new in the spring, this will also provide the shrub with plenty of fresh nutrients.

Winter Care

Most hydrangea plants will produce new buds in early spring, and these are prone to frost damage which will blacken and kill them. Depending on the severity of the frost and how much of the stem is damaged, the hydrangea may not flower or may produce fewer flowers that year.

Almost all hydrangeas are prone to this damage, and it’s quite common in colder parts of the UK but plants grown in pots are far more susceptible.

Hydrangeas have extensive root systems, and those in pots are more prone to frost damage.

Here are our tips:

  • If feasible, move the pots into a shed or porch during hard frosts.
  • Consider covering the hydrangea with a protective fleece.
  • Water the pot before the frost arrives, as this will help the soil to retain some heat.
  • Hydrangeas grown in small pots are more likely to suffer root damage from frosts, so consider potting on to a larger container as this will provide some extra insulation for the root system.
  • Make sure the pots are raised on feet and not sitting on the ground.

How to Prune Hydrangeas in Pots

Some hydrangeas will only flower on new stems while others only on old wood that grew the previous season.

If you prune a hydrangea incorrectly, there’s a chance it won’t flower for a whole season, this happens regardless of whether the hydrangea is in a pot or the ground.

Use our table below as a guide to general maintenance hydrangea pruning:

When to Prune:
Macrophylla (Mopheads & Lacecaps)
Early spring or immediately after blooms fade in summer
Oakleaf hydrangea
Early spring or immediately after blooms fade in summer
Paniculata hydrangea
Early spring
Arborescens hydrangea
Early spring
Climbing hydrangea
Late summer after blooms fade
Flowers on:
Macrophylla (Mopheads & Lacecaps)
Old wood
Oakleaf hydrangea
Old wood
Paniculata hydrangea
New wood
Arborescens hydrangea
New wood
Climbing hydrangea
Old wood
Method:
Macrophylla (Mopheads & Lacecaps)
Cut 25% of stems at ground level and remove (this encourage new stems from the base). Cut remaining old blooms off at the nearest set of buds or two sets down if you need to shape the shrub.
Oakleaf hydrangea
Often requires less pruning. Cut off old blooms to nearest set of healthy buds. Remove up to 25% of old stems at ground level to encourage new growth.
Paniculata hydrangea
Either cut back leaving 2-4 sets of buds on the previous year's growth or prune entire shrub back close to the framework (the thickest stems).
Arborescens hydrangea
Prune hard, 25cm to 50cm from the ground to promote fewer but larger blooms or prune lightly to encourage more but smaller blooms.
Climbing hydrangea
Prune in summer after blooms have faded and before new buds form. Cut out overly long and waywood stems to desired length or to nearest large stem/branch.
Warnings:
Macrophylla (Mopheads & Lacecaps)
If you prune a stem by more than half, it's unlikely to produce blooms for the season but will in the second year.
Oakleaf hydrangea
As above.
Paniculata hydrangea
Can cope with more aggresive pruning.
Arborescens hydrangea
Can cope with more aggresive pruning.
Climbing hydrangea
To control a large waywood climber, consider twice yearly pruning to gradually bring it under control, leaving at least some buds for blooms.

Pests, Diseases and Other Problems

Hydrangeas in pots are easy to grow and are generally free of pests and diseases. They even made it onto our list of plants that slugs don’t eat.

The most common problem is leaf spot disease, a fungal infection spread via overhead watering/splashing. The first sign of a problem is often brown spots on the hydrangea’s leaves.

Hydrangea Scale has been a problem in the UK since the 1980s. The insects suck the sap from the plants and side effects are:

  • Leaf loss.
  • Fewer blooms.
  • White scale on leaves and stems.
  • A sickly appearance.

The Royal Horticultural Society has more details about this pest and how to treat it here.

Compared to most other plants, hydrangeas are easy to grow and rarely troublesome so if you’ve never grown them before, give them a go.

Cuttings and Propagation

Growing new hydrangea plants from cuttings is really easy, and most gardeners have a high success rate.

The best time to take cuttings is in late spring or summer, but cuttings taken in autumn can still take root if grown on a heat mat.

Just cut 15cm long (new wood) stems that don’t have any blooms on them, then trim the stem to just below a leaf node and cut any large leaves in half. Ideally, the cutting should have only two half leaves remaining.

Dip the cut end into a rooting hormone and then insert it into a small pot containing moist cutting compost. Place a plastic bag or a trimmed plastic drinks bottle over the cutting and keep the compost moist.

The cutting should be left in a bright spot away from direct sunlight, and in 3-4 weeks, it should have taken root. The new hydrangea can then be grown on as any other hydrangea would be.

You can use heating mats to speed up the rooting process, but they should be switched off once the hydrangea has taken root; otherwise, the plant will grow very leggy with few leaves.

Propagation is a great way to increase your stock of hydrangeas, and it’s fun and educational too.

A more detailed guide to hydrangea propagation can be found in our rooting hormone article.

Propagating hydrangea

One of our hydrangea cuttings (macrophylla “ab green shadow”) taken in mid-autumn, rooted on a heat mat and then overwintered in a garage for protection.

Hydrangea in a pot, grown from a cutting

The same hydrangea in early July the following year.

Summary

Hydrangeas are beautiful, long-lived and easy to grow plants suitable for pots, containers and flowerbeds.

They are a perfect shrub for beginners to grow and are forgiving, easy to propagate and look good in any garden, large or small. 

Here is a recap of the main points:

  • Consider dwarf varieties if your garden is very small.
  • Pot size is important; go one size bigger if in doubt.
  • Hydrangeas like a bright spot that also provides shelter from the blazing midday sun.
  • Protect from frost in spring as the new buds will be tender and roots vulnerable.
  • Pruning can make or break your hydrangea, get it wrong, and it may not flower for up to a year.
  • Plenty of water and moist soil is ideal but avoid waterlogged pots.
  • Fertilise once or twice a year.
  • Propagate to replenish stocks and have fun, it’s so easy.

More From Hannah Miller:

This guide to growing hydrangeas in pots was created by Hannah Miller and posted to the Our Plants section of our website in July 2021.

Hannah is a keen amateur gardener, mother and a former NHS administrator.

She enjoys gardening as much as she cares about the environment and likes to share her knowledge with others.

Hannah is a keen photographer, and you’ll find hundreds of her photos throughout this site. She also contributes to our blog; check¬†out her latest posts here.

Author Hannah Miller

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This guide to growing hydrangeas in pots was published by DIY Gardening

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