Pruning Deutzia Like This Makes A Huge Difference To Plant Health And Longevity
Reviewed By ROY NICOL
Roy is a Professional Gardener and Horticultural Consultant, specialising in large garden year-round maintenance and garden development. He is an RHS Master of Horticulture and uses his research in the application of no-dig methods in ornamental garden settings. Roy has been a Professional Gardener for more than six years and is a member of the Chartered Institute of Horticulture, Professional Gardener's Guild and Association of Professional Landscapers (Professional Gardener).
IN THIS GUIDE
Free-flowering Deutzias are the shrubs of choice for the one-minute gardener who wants to have it all.
Over May and June, these plants can light up a garden with their charming little star-like blooms that range from bell-shaped to salver-shaped in whites and delicate shades and blushes of pink.
Deutzia can be considered one of the best low-maintenance shrubs for which anything will do.
However, all such shrubs have one or another point of care and for Deutzia, that point happens to be pruning.
You don’t have to prune Deutzia, but correct pruning makes a great difference in the health and longevity of these shrubs, and can bring about a dramatic improvement in flowering.
| Difficulty | Medium |
| Equipment Required | Gardening gloves, secateurs, pruning shears, bypass or anvil loppers |
| When To Prune | July |
Should I Prune My Deutzia Shrub?
Deutzias differ greatly in their sizes and almost as much in their growth rates.
Many varieties are well under 1m in height and spread while a few measure up to 3m tall and wide.
Typically, the smaller varieties are bushy and mounded, while the bigger ones have gracefully arcing stems and are a little more open.
Therefore, how you prune a Deutzia in its first or second year will depend on the variety.
Also, depending on the variety, size, age and condition, you may be pruning anything from young green shoots to a thick woody branch or two.
As such, you may need secateurs, pruning shears, bypass loppers or anvil loppers to complete this job.
When To Prune Deutzia
Deutzias are spring-blooming deciduous shrubs that flower on the previous season’s growth.
This means that after a Deutzia is finished with blooming in early summer, it spends the rest of the growing season forming fresh growth that will bear the following spring’s blooms.
Therefore, you should not prune this plant after this fresh growth emerges or you will be pruning away many of the following year’s flowers.
So, the correct time to prune it is soon after flowering, which is usually around July here in the UK.
Maintenance Pruning
First, prune away dead and diseased stems at their attachments.
Weak and spindly stems and shoots that bear few or no flowers should also be pruned.
Finally, a stem growing crosswise against another should be pruned or trimmed.
You can also conduct a type of tip pruning that will stimulate fresh flowering growth for the following season.
Trim stems that have flowered by approximately one-half, no less than one-third and no more than two-thirds, trimming down to a set of strong and healthy side shoots.
Pay special attention to old wood.
These are stems that are woody, long and worn-looking with a very pronounced arc.
“Each year one or two of these stems should be removed at the base (no more than 20% of the total number of stems) to encourage the growth of fresh stems which will flower the most strongly,” Roy Nicol, a Master Horticulturist, suggests.
Similarly, you should also prune branches that did not produce flowers to maintain size and shape by removing them at the base.
Water and feed the plant well after pruning.
Rebloom Pruning
Though it is highly irregular to mistreat Deutzias in the manner described here, try this trick if you’d like to tease your plant to produce a second flush of blooms out of season.
Do not wait for the blooming season to end.
Instead, when the blooming season is past its peak but still ongoing with around 10 more days to go, prune the shrub as described above.
Water the plant well.
Around 7-10 days later, feed the plant with a high-potash formula at only about 75% of the instructed strength and volume.
Rejuvenation Pruning
An overgrown and straggly Deutzia that has not been pruned and produces sparse flowers may be rejuvenated by a hard prune.
This type of rejuvenation pruning is best done in early spring just when fresh growth emerges.
Here, your aim is not to try to save the season’s flowers; it is to reboot the shrub to start it from scratch.
If you do, you’ll sacrifice whatever flowers the shrub may bear during the current season to gain renewed flowering from the year after.
Prune up to one-half of the stems and side shoots at their origins, then trim from one-half to one-third of the entire shrub, making each cut just above a node.
Be sure to leave behind young branches and shoots and some emerging growth.
About a week later, feed it with an all-purpose balanced fertiliser, using it at only 50% of the recommended strength and volume; applying it at a safe distance from the roots.
