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23rd June 2022
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Salvias are one of those amazingly diverse groups that make you wonder how such variety can exist among plants of the same name. From hardy herbaceous perennials to tender bedding plants, the herb sage and vibrant shrubs, their unifying feature is brightly coloured, nectar-rich flowers, which bees love.
Which? Gardening magazine grew a range of popular varieties, both hardy and tender types, to see which would give us the best display and be hardy enough to get through UK winters.
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Sign up nowPLANT TYPE Herbaceous perennial
POSITION Full sun
SOIL Well-drained, not too fertile
January | February | March | April | May | June |
CUT BACK HARDY TYPES | PLANT | PLANT/CUT BACK TENDER TYPES/FLOWERING | FLOWERING | ||
July | August | September | October | November | December |
FLOWERING | FLOWERING | FLOWERING | FLOWERING |
Which members can log in now to see the full results and which are our Best Buy varieties. If you're not a member, join Which? to get instant access.
Best Buy tender salvias | ||
---|---|---|
What it looks like | Variety name | Height x spread |
75 x 80cm | ||
This variety brought all the best aspects of tender salvias together in one very long-flowering package. Strong, leafy stems were completely self-supporting and had plenty of long, scarlet, tubular blooms with the characteristic hooded mouths. We noticed that in very hot weather (over 30°C), the stems and blooms of this and a few other varieties drooped, but they perked up again when the weather cooled down and were still flowering beautifully in October. Unfortunately, none of the plants survived the winter. Peak flowering: Jun-Oct | ||
What it looks like | Variety name | Height x spread |
130 x 60cm | ||
Once these got into their stride in July, the deep magenta flowers really stood out, and not just because they were head and shoulders above most of their neighbours. The short, hooded flowers were showy, and there were plenty of them. The long stems were stiff, slightly brittle and needed some support, but that was easy to put in place. They flowered well into autumn and came through winter successfully. Peak flowering: Jul-Oct | ||
What it looks like | Variety name | Height x spread |
Best Buy hardy salvias | ||
---|---|---|
What it looks like | Variety name | Height x spread |
80 x 80cm | ||
The sheer mass of slender flower spikes these plants produced resulted in a sea of vibrant colour that lasted for months. New spikes constantly replaced the old, and such bushy, branching growth meant they kept their shape well. The dark green leaves were pleasantly scented when handled. Flowers were easily deadheaded by snipping off the spikes as the colour faded and were very popular with bees, which constantly buzzed around. Peak flowering: Jun-Sep | ||
What it looks like | Variety name | Height x spread |
65 x 90cm | ||
A Best Buy for the second time, this salvia was short and squat, but no less lovely for it. Plants formed low, rounded bushes that were densely covered in short flower spikes. The intense lavender-blue of the tufty flowers looked vibrant in sun and on dull days, and they were popular with bees and hoverflies. They looked showy and colourful at the height of summer and beyond, lasting particularly well in north London. Peak flowering: May-Aug | ||
What it looks like | Variety name | Height x spread |
Variety name | Hardy in our trial | Flower duration | Flower impact | Flower coverage | Aroma of leaves | Self-supporting | Insect attraction | Pest & disease resistance | Overall rating |
No | ★★★★★ | ★★★★★ | ★★★★★ | ★★☆☆☆ | ★★★★★ | ★★★☆☆ | ★★★★★ | ★★★★★ | |
Yes | ★★★★★ | ★★★★★ | ★★★★★ | ★★★☆☆ | ★★★☆☆ | ★★★★☆ | ★★★★★ | ★★★★★ | |
Yes | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★☆☆ | ★★★★★ | ★★★★★ | |
Yes | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ | |
Yes | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★☆☆ | ★★★★★ | ★★★☆☆ | ★★★★★ | ★★★★★ | |
No | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★☆☆ | ★★★★★ | ★★★☆☆ | ★★★★★ | ★★★★☆ | |
No | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★☆☆☆ | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★☆ |
USING THE TABLE The more stars the better. OVERALL RATING Ignores price and is based on: flower duration 20%, flower impact 20%, flower coverage 20%, self-supporting 10%, aroma of leaves 10%, insect attraction 10%, pest and disease resistance 10%. Height x spread are actual measurements, taken when the plants were in full bloom. Lowest temperature recorded was -5°C. Flower impact includes colour and size of individual blooms, and should be looked at with flower coverage rating to get an idea of the overall impact of flowers on the plant. Aroma of leaves ★ = none or very unpleasant to ★★★★★ = strong and pleasant.
Variety name | Height x spread (cm) | Flower duration | Flower impact | Aromatic foliage | Insect attraction | Hardiness | Garden worthiness | Overall rating |
80 x 80 | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ | |
65 x 90 | ★★★★★ | ★★★★★ | ★★★☆☆ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ | |
75 x 50 | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ | |
75 x 50 | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ | |
55 x 90 | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | |
80 x 70 | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | |
170 x 110 | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★☆ | ★★★★☆ |
USING THE TABLE The more stars the better. SCORE Ignores price and is based on: Flower duration 20%, flower impact 25%, aromatic foliage 15%, insect attraction 15%, hardiness 15%, garden worthiness 10%. Garden worthiness is a subjective rating, based on the assessors’ experience, of whether that variety is worth growing and recommending, taking its appearance at peak flowering as the main factor. Flowering impact is an assessment of the combined effect of colour, shape and quantity of flower when plants were at their peak.
We grew 24 varieties of tender, half-hardy and borderline-hardy salvias. Many were supplied as plug plants, which we grew on to a larger size before planting out. We planted three of each variety at our Capel Manor trial garden in north London in early summer. Here, the soil is very well-drained and in full sun, although the bed we used has some shelter from a nearby hedge. We kept the salvias well watered until they were established, and then only watered them during very hot, dry weather. We put supports in place only if the plants started to flop. We assessed them until the first frosts hit in early November, and then left them in the ground over winter so we could see which would survive and regrow the following spring.
We planted three of each variety at our Capel Manor Gardens trial site in north London, where the soil is well-drained and the climate is mild, and three at Logan Botanic Garden in Dumfries and Galloway, where the soil is heavier and the climate cool and often wet. Plants were assessed regularly for impact and duration of flowering; whether leaves were aromatic; attraction for pollinating insects; and whether they survived the winter. Records were kept for both years, but results irelate to the second year when plants were mature. All plants were deadheaded to see how well they re-flowered.
If buying plug plants, pot them up into 9cm pots and grow them in a frost-free place until the roots reach the sides before planting out. Plant out into well-drained soil in a sunny spot. Avoid frost pockets and exposed, windy areas of the garden. Plant in late spring or early summer, after the danger of frosts has passed. Plants bought late in the season (August or September) would be best kept in a frost-free place over winter and planted the following year. If planting into containers, use a Best Buy compost for containers.
Planting in spring is best, so plants have time to establish fully before the winter. Plant in full sun or light shade. Salvias need good drainage, especially in winter, so plant in well-drained soil.
Take cuttings in August or September to overwinter your plants indoors in a light, frost-free place.
There’s no need to feed plants grown in the ground as they thrive in poor soil. If growing in a pot, add a Best Buy controlled-release fertiliser at planting time. Regular deadheading can prolong the flowering period, but watch how your salvia grows. Some will re-flower freely from side shoots and only need to have dead heads snipped off, while others flower in flushes so can be trimmed back with shears when flowers fade. Late-summer flowers can be left on the plants over winter, and cut back when new shoots appear in spring.
All our plants were left unprotected in the ground over winter. We had several frosty spells in the first half of winter with temperatures down to -5°C, but it was otherwise mild and unusually dry. All the smaller, shrubby varieties were hardy – many were still in leaf at Christmas– as was S. uliginosa. None of the three ‘Wishes’ series or S. patens ‘Cambridge Blue’ survived. Shrubby varieties (S. microphylla and S. x jamensis) are often described as hardy, although always with the caveat that they need well-drained soil and sun.
If you aren’t sure your conditions are suitable, you could move your plants undercover in late autumn. If you want to leave them in the ground, either take cuttings in August to September and keep them frost-free overwinter, or protect your plants.
To protect them, cover them with fleece, mulching the crown or lifting the tubers of S. patens varieties. The shrubby varieties will probably lose their leaves and should be trimmed when they start to regrow in late spring or early summer. Long-stemmed salvias regrow from the base, so leave the top growth to die and then cut it back when regrowth starts and frosts have finished.
Slugs and snails may eat young growth in spring so protect your plants with organic slug pellets or use biological-control nematodes (slugs only).
Read more about slugs and snails
Powdery mildew can be a problem, especially on very dry soil. A white fungal bloom appears on the surface of the leaf. Remove affected leaves, water plants if the soil is very dry and try to avoid too much overcrowding around the plants to allow the air to move freely.
Read more about powdery mildew