How To Grow Salvia

TAG: Gardening Advice by Christina

All you need to know about planting, propagating and caring for all kinds of salvias.

Salvia nemorosa 'Ostfriesland' is a big hit with bees, butterflies and a whole host of other pollinators.  It's the salvia I would highly recommend if you want to encourage wildlife into your garden.

Salvias come in a vast range of forms and colours and their nectar-rich flowers are a magnet for bees, butterflies and other pollinating insects.  They flower for months on end, often from midsummer until the first frosts, and many have aromatic foliage, too.  Salvias look good in almost all planting schemes, and have proved valuable to my very dry garden.  They can also be grown in pots.

The spikes of tubular, lipped flowers come in a variety of colours from white and pastel pink to deep purples, magenta, scarlet and electric blues.  The size and appearance of salvias can vary greatly:

Annual salvias are grown as vibrant summer bedding and last one year.  Examples include farinacea, horminum and splendens.

Herbaceous perennial salvias are hardy and come back year are year - these are the ones I prefer to have in my garden.  Examples include nemorosa and sylvestris.

Tender perennial salvias come back year after year but are not completely hardy and may need protection over winter.  Examples include greggii

Shrubby salvias are sub-shrubs, with woody stems.  Most are hardy and some are evergreen in mild winters but they may also need protection in winter.  Examples are jamensis and microphylla.

Salvia

How to grow salvia

Salvias enjoy full sun, in well-drained soil.  Deadhead old flowering spikes to prolong flowering.  Take cuttings at the end of summer to insure against winter losses.  Alternatively you can grow tender varieties in pots and take them inside to over winter.  Wait until late spring to cut old growth back.

Growing salvias

All salvias thrive in a sunny spot.  They need well-drained soil and love stony or poor soils.  If you have a heavy clay garden, you will need to improve the soil before planting.  All salvias are likely to die in waterlogged soil in winter.

How to plant salvia

The best time to plant salvias is from late May to early June, after the risk of frosts has passed.  When buying a plant in autumn, it is best to keep it in its pot in a frost free place and plant it out the following spring to avoid losing it in a cold, wet winter.

  • Before planting, trim back the plant a little to encourage a nice bushy growth.
  • On heavy soils add some horticultural grit to the planting hole to improve drainage
  • Dig a hole that is the same size and depth as the pot your plant came in.
  • Backfill with soil, firm in and water well.

Salvias grown in containers are best in peat-free multipurpose compost with some horticultural grit or sand added for extra drainage.  Make sure the pot has drainage holes at the bottom.

How to care for salvia

Salvias planted in the ground will get all the moisture they need from rainfall.  Once established they are drought tolerant, all of mine survived the heat of 2022 (43c), although they did look a little sorry for themselves.  Salvias growing in containers need watering regularly.

They do not need to be fed, unless they are growing in a pot which will need a tomato feed from spring to early autumn.

Deadhead to promote new flower growth.

I have found with Salvia nemorosa and sylvestris, once they have finished flowering, if I cut them down to the new growth starting at the base in July, and water them regularly I can produce a very healthy green bush that will flower again in September.  Otherwise mine can start to look really sorry for themselves by the end of August because of the hot dry conditions in my Suffolk garden with it's poor sandy soil.

Protecting salvias in winter

To prevent loss during the winter months, take a few cuttings in late summer.

In mild areas, mulch tender salvias with a 10cm layer of well-rotted manure or garden compost to protect them from frost.  In colder areas, lift them as you would dahlias, and over winter them in pots indoors.

Wait until late spring to cut salvias back as the foliage gives a degree of protection from winter frosts.  In late spring, cut the plant back to just above the new fresh shoots that are appearing at the base.

How to take salvia cuttings

Salvia cuttings can be taken in April, August or September.  Creating lots of free plants you can spread around your garden.  The official advice is to place cuttings in a plastic bag to save them from water loss while you start putting them into pots.  I however, carry a pot of water around and submerge the cuttings into that.  I then use that water on the cuttings once they are in their pots.  Whenever I pass the cuttings I'll spray them with water.

  • Remove non-flowering stems that are about 8cm long
  • Remove the lower leaves and trim each cutting just below a node
  • Insert cuttings into a pot of pre-watered cutting compost
  • Cover the pot with a clear plastic bag - I've never done this with any cutting and they have still survived.  I prefer to spray them with water when I pass them.  Try out both methods to see which works best for you
  • Place the cuttings in a cool greenhouse, or like I do, put them somewhere in the garden that is protected from frost or too much sun.  I feel over protected plants does not help them to get used to and survive our changing climate.
  • After three weeks the cuttings should be ready to pot on.

Growing salvia: problem solving

Keeping plants through the winter months is the biggest challenge.  Plants growing in persistently wet clay soil over winter tend to die.  Pests and diseases are rarely an issue.

Some plants die back over winter and re-grow in the spring.  If there is no sign of life by mid-June it has probably died.

Salvias I enjoy growing in my Garden in Suffolk

Salvia jamensis 'hot lips' is a striking shrubby salvia with bi-coloured red and white flowers.  It is a frost-hardy plant, although it may need some winter protection.  There are other colours available, called 'amethyst lips' and 'cherry lips'.  I added hot lips to the garden in 2022 as I'd seen lots of bees on it in Bury St Edmunds Abbey Gardens.

Salvia nemorosa 'Ostfriesland' is a hardy perennial which is extremely popular with pollinators.  It has tall spikes of purple flowers throughout June to September.  I have this one everywhere in my garden because it's such a magnet for wildlife.  It reaches a height of 45cm with a spread of 60cm and looks very nice in a prairie style garden or planted with penstemons.

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