SHRUBS > HYDRANGEA > CONTAINER-GROWING
IN THIS GUIDE
Most hydrangea can grow perfectly well in pots, though dwarf varieties are better suited.
In this article, we will tell you everything you need to know to grow hydrangeas in pots or containers with good results.
Read on to find out more about making the right initial choices, planting up your hydrangea, and caring for your potted hydrangea over time.
Container Hydrangea Varieties
The first thing to think about if you are considering growing hydrangea in pots is which type of hydrangea you would like to grow.
Hydrangeas can be climbing plants, or shrubs.
Those with relatively compact shrub forms are best for growing in pots. Some good compact hydrangeas to consider growing in pots include:
- H. Macrophylla ‘Masja’
- H. Macrophylla ‘Paraplu’
- H. Macrophylla ‘Mini Penny’
- H. ‘Miss Saori’
- H. ‘Selma’
- H. Paniculata ‘Early Sensation’
- H. Paniculata ‘Little Lime’
- H. Paniculata ‘Bobo’
- H. Serrata ‘Shojo’
- H. Quercifolia ‘Sike’s Dwarf’
These are just some of the options to consider.
You might also choose to grow climbing hydrangeas such as the evergreen Hydrangea seemannii in pots, as long as these are positioned correctly, and of sufficient size and stability.
Remember to consider the colour and type of foliage and flowers that you would like from your hydrangea, since one varietal can look very different to the next.
Of course, it is also important to consider where you would like to place your hydrangea in pots, since this will also be vital in determining which type and varietal of hydrangea to grow.
Placing Potted Hydrangea
Hydrangeas in pots can be placed in a range of different locations.
You might place them on a patio or decking area, beside a doorway or window, or in rows of container shrubs to create division between different parts of your garden.
Hydrangea are hardy and versatile shrubs that can work in many different garden settings – from spaces with a traditional cottage garden feel, to much more modern, contemporary designs.
Most hydrangeas will do best in an area of partial shade or full sun.
Most will not flower as well in deeper more pronounced shade.
A west-facing spot could be ideal as most hydrangeas seem to thrive where they have shade in the morning followed by sun in the afternoon.
However, one important thing to consider is that you do not want to place hydrangeas in pots in an area where they will dry out too quickly.
Not providing enough water is one of the most common reasons why problems creep in when people grow hydrangeas in pots.
Hydrangeas, no matter which type, tend to like to be grown in relatively moist conditions.
Choosing Containers For Hydrangea
Once fully grown, a hydrangea will typically require a large container, such as a half-barrel, trough, or another large reclaimed item.
However, it is not usually a good idea to take a small hydrangea purchased in a pot and plant it up into a large container right away.
This is because waterlogging can be an issue where there is excessive space around the plant roots.
Choose a container that is just a little larger than the pot in which it came.
Alternatively, choose a large planter or container and place a hydrangea in it alongside some other perennial plants which enjoy similar conditions, before thinning, pruning and transplanting these to new containers once the hydrangea grows.
Make sure that you choose a pot or container which is relatively good at retaining moisture, and yet which has drainage holes at the base to allow excess water to drain through.
Make sure that the container is heavy and sturdy enough to support the size and weight of your shrubs, and that it will not blow over or be toppled easily.
Container Potting Mix
Hydrangeas are not particularly fussy when it comes to the potting mix or medium in which they are grown.
A general-purpose, loam-based potting mix is generally best.
Hydrangeas can grow in mixes with a range of different pH levels.
However, remember that if you are growing a blue type, you will need to choose an ericaceous compost, and maintain acidity over time.
Potting Up Hydrangea
The best time to purchase and pot up hydrangea into their new containers is either in spring or autumn, when the soil is warm and moist and transplantation will go smoothly.
However, you can buy and pot up hydrangea at any time over the summer – as long as you make sure that the conditions are moist and that you keep watering consistently until the shrub becomes established.
Take care not to place your hydrangea deeper in its new container than it was in its original pot.
Water the shrub in well, and then be sure to mulch around the top of the new container – leaf mould is ideal, though you can also use a homemade compost or well-rotted manure.
For hydrangeas grown in ericaceous potting mix, consider mulching with oak leaf compost or pine needle mulch.
Monitor the size of your hydrangea and pot up into a larger container as soon as it begins to outgrow its old one.
Caring For Hydrangea In Pots
When it comes to caring for hydrangea in pots, the most important thing is watering.
It is very important to ensure that the growing medium remains moist (but not waterlogged) throughout the growing season.
You should also replenish the mulch around your pot grown hydrangea each spring. No additional feeding will usually be required.
It is important not to provide excessive nitrogen as this can encourage leafy growth and flowering may not be as prolific.
One thing to note, however, is that if you are growing a hydrangea that you are trying to keep blue, feeding in summer with low phosphorus, high potassium organic feed can help. You should also water with rainwater where possible.
When and how you prune your hydrangea will depend on which variety you are growing. Hydrangea quercifolia will usually only require light pruning in spring – to remove old or damaged stems and old flowers, and perhaps to restrict size a little.
Hydrangea paniculata should be cut back early in the spring. Pruning is not essential, however, cutting back will restrict growth and keep your plant neater and more compact.
This type of hydrangea produces flowers on new wood, so you can prune back quite heavily on last year-s growth.
Aim for a healthy framework 30-60cm high. Prune each stem just above a pair of healthy buds.
Hydrangea macrophylla should be pruned in the middle of spring. They produce their flowers on old growth, so pruning back too hard could mean that you lose the flowers for the year.
Leave the dead heads over winter, to protect the new growth, then cut these back carefully to the buds which are forming underneath each one – this is where the new flowers will form.
If your plant is overgrown, you can also cut some stems back to the base.
It is easiest to make new plants from your existing hydrangeas by taking softwood cuttings in the spring.
Look for young non-flowering stems which have three sets of leaves, remove the two lower sets of leaves and cut the stem down to just below a node.
Then pot up and keep moist, in a shady spot, until roots form and the cuttings show signs of new growth, when they can be potted into their own containers.
A permaculture garden designer, sustainability consultant and freelance writer, Elizabeth works as an advocate for positive change. She aims to inspire others to reconnect with nature and live in a more eco-friendly way. She also tries to practice what she preaches as she tends her own forest garden, polyculture beds and polytunnel. See her personal website here.