How To Prune Hydrangeas
- artfulgardensnz
- Aug 22
- 2 min read
Updated: Aug 28
Hydrangea are deciduous, prefer moist soil with full sun or part shade.
They flower for a long time over summer to early autumn.
Hydrangeas are a wonderful addition to almost any garden.
HYDRANGEA PRUNING GUIDE
For All Hydrangeas (except climbing)
Prune late winter to early spring, ideally after the last frost to prevent buds from getting frosted.
If you miss a year of pruning it won’t hurt.
Cut dead or frosted branches or wispy thin branches.
If the hydrangea bush is getting crowded, thin out some of the excess branches to let air and light into the bush.
Prune overly long branches.
Depending on the variety, hydrangea will flower on it's new growth or the previous year's growth. And so you prune accordingly, on the new years growth or on old growth.
HYDRANGEAS VARIETIES TO PRUNE ON OLD GROWTH
Hydrangea macrophylla (Bigleaf Hydrangea) Such as ‘Mop Top’ and ‘Lace Cap’ flowers, these are the most common hydrangeas you will see.
Hydrangea quercifolia (Oakleaf Hydrangea)
Hydrangea serrata
Hydrangea aspera
Ideally prune after the last frost so as to prevent your buds from getting frosted
In exposed areas with frosty winters you can leave the old flower heads on the bush to protect the flowering buds. Lacecaps are hardy so you can deadhead these flowers (to the second pair of leaves) after flowering to save the plant’s energy.
If you need to bring the height of the bush down, you will need to prune in late summer well before next year's flower buds have formed on the stems. You may have to sacrifice some blooms to make the cuts. If a hydrangea is very out of shape, you may want to cut it back hard and go for a year without flowers all together.
Oakleaf (Hydrangea quercifolia)
These are best left alone but sometimes you need to prune them to keep them to the size and shape you want so take them back to a set of flower buds. If you are more interested in the foliage than the flowers then you can cut the stems ¼ back in late spring for extra leaf growth.
HYDRANGEAS TO PRUNE ON NEW GROWTH
Smooth Hydrangeas (Hydrangea arborescens)
Panicle Hydrangeas (Hydrangeas paniculata)
As a minimum you can just remove dead wood and deadhead flowers.
For more flowers cut back each stem by about one third, to just above a pair of healthy looking buds.
You don’t have to worry about cutting back too much as any new wood has the potential of flowering.
Climbing Hydrangea (Hydrangea petiolaris)
Prune Climbing Hydrangea in Summer after flowering
This vine flowers on new shoots so light pruning each year to stimulate growth is beneficial for more blooms. Cut back overly vigorous branches and shorten flowering stems that are growing outwards from the support structure, straight after flowering.
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