No garden is complete without some kind of salvia plant. The Salvia genus is a well-known ornamental mint (Lamiaceae) species. It derives its name from the Latin “Salvere”, translating “to feel well and healthy”. Needless to say, this plant genus—which includes common and white sage—has been revered for its healing properties since Roman times.
For a gardener, the Salvia genus is regarded as a much-loved and vast plant collection. It’s comprised of nearly 1000 different ornamental flowering plant species. These plants are divided into categories of woody sub-shrubs, herbaceous perennials, and tender annuals.
These beauties offer a guaranteed swatch of lasting colour from early summer, right through to fall and beyond. As such, it’s no surprise that the Salvia plant genus has gained such popularity.
Natively, Salvias are distributed throughout Africa, Asia and Europe, as well as the Americas. There are three distinct diversity regions, which are as follows:
- Central and Southern America: approx. 500 known species
- Central Asia and the Mediterranean: approx. 250 known species
- Eastern Asia: approx. 90 known species
Although Salvias can take on one of the three different plant forms, their tall flower racemes of pretty trumpet-shaped, two-lipped blooms remain unmistakable. They’re suited to the most remote cottage garden as a summer herbaceous bed staple. In addition, they’re stunning when planted en masse in a minimalistic urban space.
Salvias are the educated choice for long-lasting knockout colour, easy maintenance and great wildlife appeal. Let’s take a closer look at some of the impressive varieties that continue to catch my eye, year after year.
Salvia plant colours commonly range from blue to red—white and yellow-flowered varieties are less common. Stems are generally quite angled, with entire, toothed, or pinnately divided oval leaves. Foliage is typically scented, sometimes smooth, or covered with a layer of fine hairs called trichomes. These trichomes help to reduce water loss in plants.
The Salvia species with trichomes often secrete a distinct-smelling oil when rubbed. This is a valuable asset that can deter unwanted grazing animals, insects, and pests.
Favourite Half-Hardy Shrub Forms
Salvia elegans “Honey Melon”
Native to Mexico and Guatemala, this species is otherwise known as “Pineapple Sage”. You’ll find it inhabiting highland pine-oak forests within these regions. This is one of three most-visited species by hummingbirds in its natural environment. The leaves and flowers are fully edible, and used in traditional Mexican medicine to treat anxiety and high blood pressure.
In the west, Salvia elegans is widely grown as an ornamental sub-shrub. Its pineapple-scented leaves and scarlet-red tubular flowers are attractive to butterflies and hummingbirds.
You can expect S. elegans to grow to a compact height of around 24 inches. This particular variety, “Honey Melon”, is the earliest and longes- flowering variety within the genus. It’s perfect for ground cover and for edging pathways, as well as planting en-masse for wildlife interest.
The “elegans” genus of Salvia was introduced to the horticultural world back in around 1870. It’s frost Hardy in zones 9–11.
This is another Mexican species, but native to elevated, mountainous regions. The Salvia fulgens is quite a compact sub-shrub that grows to a maximum height and spread of just a metre, (39 inches). Its loose spires of the blood-red, inch-long, trumpet-shaped flowers grow upright to about 4 inches and are covered in tiny hairs.
These stunning, blood-red blooms tower above a mass of smooth, heart-shaped, light green foliage. They also give the shrub is colloquial name: Cardinal Sage”. In my opinion, this is one of the best colour-contrasting Salvias around. They’re a well-used favourite of mine, and are frost hardy in zones 7–9.
This herbaceous perennial is alternatively known as the “Mexican Sage Bush” . Indeed native to Mexico, it grows in the tropical and sub-tropical conifer forests throughout central and eastern parts of the country. Growing up to 1.3 metres tall, and reaching up to 2 m wide, this half-hardy shrub is perfect for frost-free zones.
Plant it in full sun, and it will produce masses of arching velvet-blue and purple flower spikes all summer. Foliage is bushy and mid-green, with slim lanceolate leaves covered in white hairs. This brilliant wildlife plant attracts hummingbirds, bees, and butterflies. Frost hardy in zones 8–10.
Plants in the Salvia microphylla genera are aromatic, hardy evergreen shrubs. They’re commonly known as “Baby Sage”, due to their small form. They originate from parts of Southern Arizona and mountainous regions of Mexico, and are bushy in habit.
Leaves are oval and light green with branched upright flower racemes. This variety displays deep red, tubular, lipped blooms from late summer. Frost hardy in zones 7—12.
Further interesting varieties within the Salvia microphylla genera include:
- “Hot Lips”: a bicoloured red and white flowering specimen with loose flower spikes from mid summer. Flowers start out red, but turn red and white as the summer progresses
- “Cerro Potosi”: a variety with racemes of bright, magenta pink, tubular flowers from mid summer to autumn
- “Kew Red” : this “Baby Sage” variety has aromatic leaves and 10 cm-long racemes of beautiful crimson red flowers
Favourite Hardy and Half-Hardy Herbaceous Heroes
Also known as “Friendship Sage”, this hybrid sage was discovered in Argentina in 2005. It’s a truly stunning woody perennial with eye-catching, deep purple-blue flowers and almost black flower bracts.
It grows to a height and spread of 1.2 m x 50 cm, with smooth, bright green foliage and large trumpet-shaped blooms. Suitable for a full-sun site, and is frost hardy in zones 8–11. This variety is especially effective when planted en masse next to the bright red “Salvia fulgens”.
This variety is just perfect for the back of a border. It’s a tall, clump-forming species with slender upright, light green stems and beautiful baby blue flower spikes. Commonly referred to as “Bog Sage” (due to its preference for water-retentive soils), it will happily reach heights of over 6 feet.
Although this species is self-supporting, it’s best to stake these plants unless they’re planted in a sheltered site. They are quite lax in nature, and will weave and wander with the wind.
I’ve planted this particular variety with delicate Miscanthus grasses at the back of a mixed bed in a very formal garden. This has proven to be effective, adding movement in a rigid setting. This is a non-scented species which regardless, continues to attract huge amounts of bees and butterflies. It’s fully frost hardy and has a tendency to spread due to its vigorous growth habit.
Salvia nemorosa “Caradonna”
My favourite variety within the S. nemorosa species is “Caradonna”, with its deep violet-blue flower racemes on even darker stems. These “moody blues” seem to set off the grey-green ovate foliage perfectly. As a result, it’s an invaluable perennial for the early summer border.
Fully frost hardy in zones 3–9, “Caradonna” has large flower heads that attract all aspects of wildlife. This is a scented Salvia plant variety, renowned as being off-putting to deer, mice, and rabbits. These hardy perennials are also drought and heat tolerant, making them perfect additions to a full-sun site.
At maturity, this clump-forming Salvia will reach 75 cm in height with a 60cm spread. Overall, I think this is one of the most reliable and adaptable species of Salvias available. It’s happy growing in pretty much any soil pH, so long as it’s free-draining.
Salvia patens “Cambridge Blue”
There are few flowers which replicate the true “Cornflower Blue” colour in a garden. In this, the Salvia patens comes into its own. This tuberous-rooted, tender perennial sports 30 cm tall sky-blue flower racemes. Truly, this is a bright and beautiful choice for summer bedding.
Commonly known as “Gentian Sage” and native to Mexico, Salvia patens flower from mid summer right through to late autumn. This is a tender species that will need to be lifted and overwintered in a frost-free environment.
In maturity, this clump-forming perennial will reach a height of around 2–3 feet tall, with a spread of up to 18 inches. Due to its natural habitat, it performs best in a full-sun site. In addition, it attracts a host of wildlife, especially nectar-loving insects. In short, “Cambridge Blue” is a lovely specimen, simply perfect for bright summer colour.
Salvia guaranitica “Black and Blue”
This is regarded as one of the most popular tender perennials within the Salvia species. Also known as“Anise-Scented Sage”, it’s an attractive perennial with lush green foliage. It boasts tall flower racemes of large cobalt blue blooms, with dark stems and almost-black flower bracts.
Growing with ease and haste, this aromatic beauty releases a soft anise scent when handled. It can comfortably reach a height of 60–150 cm tall, making it an ideal salvia plant back borders.
This plant prefers to be in a sheltered position, and offers height and intense colour throughout its long flowering period. It’s frost hardy in zones 7–10, though lifting your plant throughout the winter months will ensure healthy growth for the following year.
Salvia “Love and Wishes”
Here we have an impressive Australian Salvia plant. This one has an upright growth habit, scented leaves, and robust flower racemes of bold red-purple lipped blooms. Its slender stems and flower bracts are a deep burgundy, borne from early summertime right through to late autumn.
This bold, bright Salvia has an extremely long flowering period when situated in a full-sun site. In ideal conditions, it’ll reach heights of around 1 metre x 50 cm spread. As with many tender varieties, a sheltered site is preferable. Furthermore, lifting during the winter months will ensure healthy growth for the following year.
All in all, this is my favourite pink-red flowering Salvia plant for beds, borders and pots.
Tending Your Salvia Plants
All Salvia species are pretty amenable when it comes to soil. They can tolerate both acidic and alkaline soils as long as they are free draining. I mulch all of my herbaceous beds with well-rotted farmyard manure in the early wintertime. This puts nutrients back into the soil for the next growing season. It’s an important part of my gardening calendar, and promotes stronger growth and bigger, better flowers.
Temperature and Sunlight
Many of the Salvia species listed above are tender herbaceous perennials. They’re not frost hardy, so treat them as an annual bedding plant. Alternatively, lift them from the ground once flowering has ceased, and place them in a greenhouse for the winter.
Variants on this are the hardy perennials and the hardy sub-shrubs. I’ve listed each of these with a temperate guide above, which should indicate whether they are fully hardy or semi-hardy.
It’s always worth checking the label on your plants before you choose your site. Doing so will avoid any disappointments, and ensure ideal growing conditions.
As a genus, most of the American Salvias prefer a full-sun growing site. Some prefer partial sun, however, so always check your plants’ preferences before preparing your site.
Watering your Salvias
Once planted, water your Salvia plants in, and ensure they don’t dry out for the first couple of weeks. After this period, they should start to adapt to their new site and will rely on inclement weather for a good drink. Potted plants will obviously need to be watered on a regular basis to prevent them from drying out.
If you’ve planted your Salvia species in the garden, the soil should have enough organic matter incorporated into it to ensure a nutrient rich growing medium. In this case, you will not need to add extra fertilizer to your Salvia plants. Should you have potted Salvia plants, it is worth adding some slow-release granule feed into the potting mix before you plant. Throughout the growing season, you can also feed your potted Salvias with diluted tomato feed.
Pruning Your Salvia Plant
The pruning regime for this huge plant species will depend upon which Salvia you have.
Shrub-forming Salvias with Woody Stems
Suitable for Species: Salvia microphylla, Salvia coccinea, Salvia greggii & Salvia chamaedryoides
After flowering, cut back all stems to just above the first couple of leaves. This will allow for a second flush of flowers to follow. In late Autumn, give the plant a trim again, removing any dead, dying, diseased or straggly growth. Neaten your stems to around 4 inches from the ground and mulch your plants.
In the following spring, tidy up any unruly sporadic growth. Lighten the crown and check for winter casualties.
Herbaceous Perennial Salvias
Suitable for Species: Salvia uliginosa, Salvia guarantica & Salvia patens
These are a group of Salvias that die back over the winter months. Their stems are more tender than the woodier varieties above, so keep the old growth on these plants until the following spring. This protects tender new growth, making it less vulnerable to cold weather conditions. Come springtime, feel free to cut the old growth away, allowing the new shoots to take over.
Suitable for Species: Salvia elegans, Salvia leucantha and Salvia Waverley
These particular species are easy to prune right after flowering. Cut all these spent plants right down to ground level. In the following spring, you’ll notice the new tender growth appearing at the base of the plant. As a result, you’ll allow essential light, air and water to penetrate, promoting strong growth in the coming season.
Suitable for Species: Salvia nemorosa, Salvia penstemonoides and Salvia superba
These species of Salvia form a foliage rosette. Above this basal rosette, the stems grow heavy, bushy foliage, topped with terminal flower racemes.
Once your Salvias have flowered, cut the stems back to the basal rosette, clearing any spent leaves as you go. In the following spring, new growth will form a good shaped plant.
Your pruning regime is an a good time to divide large clumps of Salvia perennials. This is the easiest way to contain plant growth and increase your plant numbers.
Alternative ways of propagating Salvias include taking stem cuttings in autumn.
Here’s a quick guide on how to do this:
Find a non-flowering shoot on your Salvia plant and make a clean cut just below a pair of leaves. Your cutting will need to be about 4 inches long. Place the cutting in a plastic bag to keep it moist, until you’ve collected a number of cuttings.
When ready to pot up, remove the leaves from along the stem cutting, leaving just the top two pairs. Then dip each of your cuttings in hormone powder, which will aid root growth. Place the cuttings in small pots with some free-draining compost mix, and water them in well.
Top your pots with some horticultural grit and place them in a greenhouse or propagator at about room temperature. Leave your cuttings to root over the winter months.
Perfect Planting Companions
There are many plants that make great companions for the Salvia species. The diversity in their colour and form promote their suitability for planting with many different styles.
I’m a sucker for a romantic cottage garden theme. I like the haphazard aesthetics and irregular lines that gently flow into one another, creating a haven of peace, beauty and a mass of wildlife. Here are a few of my favourite herbaceous companion plants for the cottage garden theme:
Any one of these will complement your favorite sage plant perfectly. Choose similar hues for a monochromatic space, or those opposite on the color wheel for contrasting splendor.