Learning how to prune salvias is well worth doing if you've added this gorgeous cottage garden favorite to your plot. Not only will a good trim keep your borders and pots looking their best all year, but it will also encourage more flowers and healthier growth.
If you already know how to grow salvias, you'll know what a valuable addition they make to a planting scheme. With their elegant spikes of blooms in a multitude of colors, they add architectural structure and interest for many months on end.
What's more, pollinators adore them – so they're ideal if you want to encourage wildlife to visit your plot. But every perennial salvia plant will benefit from an annual prune once its stunning summer display has faded. Luckily, it's easy, once you know how.
All the tips you need on how to prune salvias
Finding out how to prune salvias is a simple way to keep your flower beds looking their best. You'll find everything you need to know below.
Do you need to prune salvias differently depending on the variety?
The range of salvias is huge: the RHS (opens in new tab) lists annuals, biennials, herbaceous or evergreen perennials, and shrubs on its website. There are characteristics that they all have in common though – paired, often aromatic leaves, with two-lipped flowers arranged in whorls in spikes or racemes.
With annuals, there's no pruning required – simply lift and pop them in your compost bin at the end of fall, when they have finished flowering. But perennials benefit from a chop to keep them in check and encourage healthy growth for many years.
It's important to take the variety of perennial you're growing into account, as there are slightly different approaches for each. We cover all the tips you need for the three main types of salvias – deciduous herbaceous, shrub, and rosette-forming – below.
When should you prune salvias?
Pruning salvias should ideally be done annually. Some gardeners choose to do their big salvia prune in late fall – this is fine to do if you grow hardy varieties and live in a warmer region. However, if in any doubt, put it on your list of spring garden jobs, when all risk of frost has passed and you can see fresh green growth appearing. Leaving the old stems intact until then will provide a level of frost protection.
Deadheading and light pruning to neaten up the plant can be done in summer.
How to prune deciduous herbaceous salvias
This variety of salvia tends to die back in winter, especially if it's cold. Varieties include Salvia elegans 'Scarlet Pineapple', which has pineapple-scented foliage and red blooms, and Salvia guaranitica 'Black and Blue'.
Here's how to prune them:
- Grab a pair of the best secateurs, ensuring they are clean and sharp. These bypass ones from Amazon (opens in new tab) are a good choice for the job.
- Cut old stems right back down to the lowest shooting node. If the stems have died off completely over winter, cut them right back to the base, where new growth should have appeared.
- In summer, be sure to deadhead blooms. Snip them off, making your cut just above a set of leaves. This will neaten up the appearance of the plants and encourage repeat flowering.
How to prune shrubby salvias with woody stems
'Prune hardy shrubby salvias every spring to keep them compact,' says Anne Swithinbank of Amateur Gardening. If you don't, this variety can grow huge and their stems can turn overly woody and straggly over time.
Varieties include the well-loved Salvia microphylla 'Hot Lips' – available from Nature Hills (opens in new tab) as well as other retailers – and the brilliantly-red Salvia greggii 'Flame'.
These steps will help keep yours in order:
- Remove all dead and diseased stems.
- Prune back around a third of the plant, making each cut just above a pair of leaves. This will maintain the structure and provide a sturdy base for new growth.
- Alternatively, you can prune them back harder, to the lowest nodes.
- In summer, deadhead flowers and trim stems back to a pair of leaves to neaten up the appearance. You can also cut back any crisscrossing stems and thin out the center of the plant in summer, which will allow more light in to encourage new growth.
How to prune rosette-forming salvias
This type of salvia sports tall flower spikes which grow from rosettes of often evergreen leaves (in warmer climates). Varieties include 'Caradonna' – a favorite with purple flowers, available on Nature Hills (opens in new tab) – and 'May Night'.
Pruning them is simple:
- Once the flower spikes have faded (generally in early summer), cut the stems right back down to the base. This will encourage a second flush of blooms.
- Leave the second lot of stems over winter to protect new growth from frosts. Then, cut all old growth off in spring, leaving new, green growth intact. In warmer regions, you can cut the plant back in fall if you want a neater look.
What should you do after you've pruned your salvias?
Once you've finished pruning your salvia plants, give them a feed with a balanced fertilizer, such as Vitax Q4 (available on Amazon) (opens in new tab), or fish, blood and bone meal, says John. Repeat this treatment monthly, until late summer or early fall. This will encourage them to flourish and speed up the growth of robust new shoots.
Remember to keep watering plants regularly in dry spells, too.
My salvia is too big for its situation – what should I do?
If your salvia has become too big for its space despite annual pruning, and has begun to overcrowd neighboring plants, you can transfer it to a new spot.
Simply lift it in late spring with as large a rootball as possible, and replant it in a more open position in full sun, says John.
The garden was always a big part of Holly's life growing up, as was the surrounding New Forest where she lived. Her appreciation for the great outdoors has only grown since then. She's been an allotment keeper, a professional gardener, and a botanical illustrator – plants are her passion.
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