How to prune salvias and when to do it: easy tips for beautiful blooms

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've already learned 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. Plus, 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.

How to prune salvias: all the tips you need

Finding out how to prune salvias is a simple way to keep your flowerbeds looking their best. You'll find everything you need to know below. 

And, if you need more pruning advice, our guides on how to prune roses and how to prune hydrangeas will come in handy too.

What are the different types of salvia?

The range of salvias is huge: the RHS (opens in new tab) lists annuals, biennials, herbaceous or evergreen perennials, and shrubs on their 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. But perennials need an annual chop to keep them in check and encourage healthy growth for many years. And when it comes to learning how to prune salvias, it's important to take the variety you're growing into account, as the approach is slightly different. We cover all the tips you need for the three main groups – deciduous herbaceous, shrub, and rosette-forming – below.

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:

1. Grab a pair of the best secateurs, ensuring they are clean and sharp.
2. 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.
3. 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' and the brilliantly-red Salvia greggii 'Flame'.

These steps will help keep yours in order:

1. Remove all dead and diseased stems.
2. Prune back around a third of the plant, making the cut just above a pair of leaves. This will maintain the structure and provide a sturdy base for new growth.
3. Alternatively, you can prune them back harder, to the lowest nodes.
4. In summer, deadhead flowers and trim stems back to a pair of leaves to neaten up the appearance. You can also cut back any criss-crossing 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' and 'May Night'.

Pruning them is simple:

1. 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.
2. 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.

When should you prune salvias?

Pruning salvias should 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 long do salvia plants last?

Learning how to prune salvias will help to boost their lifespan, which can surpass 10 years with the right growing conditions. Anne Swithinbank for Amateur Gardening says how her 'Lemon Pie' salvia, which she prunes hard every spring, has lasted 20 years through many cold, wet winters. 

However, hardiness varies across varieties, so in cold regions, it's best to take summer cuttings as backup, Anne adds. She suggests to do this in July or August, taking either 3–4in heel cuttings or shoot tips. You can learn more about how to take cuttings from plants in our dedicated guide.