How To Grow And Care For Salvia

As a flowering plant, the following are some facts about Salvia plants:

• Most varieties can be used as perennials in zones 5-9, except for some varieties that can be used in zone 4 or zone 10.
• Varieties are 1 to 6 feet tall & wide, most averaging 2 to 3 feet.
• Full sun and 6 hours of sunlight daily are a must for flowering. Some varieties tolerate partial shade.
• According to some studies, edible salvia could potentially treat people with severe drug addictions. Additionally, low dosages of salvia can treat headaches, diarrhea, rheumatism, and anemia.
• Annual salvias are grown during summer before being discarded at the end of the season.
• Herbaceous perennial salvias are hardy and come back year after year.
• Tender perennial salvias come back every year but may need protection over winter.
• Shrubby salvias are sub-shrubs with woody stems. Most are hardy, while some are evergreen in mild winters.

The following steps provide detailed instructions regarding the type of Salvia plant to grow, how to space the plants and how to care for them:

When to plant

Planting tender salvias is ideal from late May to early June or April to early May, depending on the variety. It can also be done in early autumn if your soil is not too heavy. 

Seeds should start indoors 6 to 8 weeks before the last frost date. It is better to begin indoor planting, starting 6 to 8 weeks before the final frost date, and to transplant seedlings outdoors once the danger of frost has passed.

Where to plant

Where you plant your salvia can impact its growth and flowering. Salvias thrive best in a sunny location with full sun to partial shade (at least 6 to 8 hours of direct sun) and well-drained soil.

This makes them particularly well-suited to areas with south-facing exposures. While most salvias require full sun, a few species like Salvia glutinosa can tolerate partial shade.

They can be planted along your house foundation, in flower beds with other perennials, or in containers. Salvias are especially charming along pathways as they soften their edges.

Soil

Salvia plants don't need nutrient-rich soil but must have good drainage. If your soil is dense, plant the salvia slightly higher than the surrounding ground. For potted salvias, use a mixture of regular garden soil and perlite to ensure quick drainage.

Putting a layer of wood chips or small rocks on top of the soil (mulch) is a good idea for outdoors and pots as it protects the roots, keeps the soil moist, and helps with temperature control.

Soil pH is also important. Salvias grow best in moderately acidic to slightly alkaline soil ranging from 5.5 to 6.5 on the pH scale.

Spacing

Salvias needs some breathing room. When planting them in groups or alongside other plants, consider how big they will eventually become. Leave enough distance between each plant to allow for proper air circulation.

Steps in planting salvia

• For a thicker, fuller plant, trim back some of the stems before planting.
• When planting your salvia, make sure to dig a hole that is slightly larger than the pot it came in. Place the plant in the hole at the same depth in the pot.
• Space plants 1 to 3 feet apart, depending on the variety.
• Carefully fill in around the plant and firm the soil gently.
• Water thoroughly.

Watering

When you plant your salvia for the first time, water it slowly until the soil soaks up the water, but avoid making it soggy.

Most varieties of salvia only require occasional watering. Overwatering is one of the most common causes of issues that affect salvia. It can lead to fungal diseases, root rot, and crown rot.  A good rule of thumb is to let the soil in the garden dry out between waterings. They can tolerate short periods of drought without any issues.

But how can you tell if your salvia needs a drink? The easiest way to tell if your salvia needs water is to check the leaves and stems. If the leaves look wrinkly and dry or the stems feel limp and bendy, it is time to water them. In extreme cases, your salvia might lose its leaves to conserve water until you give it some.

Also, the soil should be moist when you poke a finger about 1” below the surface.

Deadheading

Deadheading, or removing old flowers after they have faded, is essential in salvia care. It will prolong the bloom period. Some bloom only once or twice each summer, while others may persist throughout the growing season. 

Once the flowers have wilted, gently cut the stems back to the base to stimulate new growth and maintain the plant's appearance.

Fertilizer

Salvias do not require heavy doses of regular fertilizer but do benefit from occasional fertilizing. 

For the best results, feed the plants a 1-inch layer of aged compost applied covered by another inch of shredded wood mulch or straw mulch at the beginning of each spring. This will make the plants healthier and increase flower production. 

Remember not to overfeed the plant as it can lead to increased susceptibility to disease and loss of vigor.

Flopping

Your salvia might flop over for many reasons, like overwatering, inadequate sunshine, or excess feeding.  

When this happens, you have two options. You can add stakes to support the stems or cut off the dead flowers to encourage new, sturdier growth. Many gardeners think flopping is a sign that it is also time to divide their salvia. 

If your little salvia seeds have reached an adequate size, you can successfully multiply your plants through propagation. You should do that every 3 to 4 years. It is relatively easy and can be done by taking tip cuttings, side shoots, division and layering.

Cutting 

Spring and early summer are the best times for tips cutting. You begin by locating an ideal stem for a cutting. An ideal stem has one bud at the top of the stem and two leaf nodes. Once you have found the salvia stem tip, cut through or just below the bottom node located on the buds.

Take the cuttings and put them in water while you finish preparing all the other cuttings and before planting them, dip them in cutting gel/ powder that helps them grow roots faster.

Side Shoots

You can also propagate from small side shoots from the base of the plant. This works for bushy, herbaceous (soft-stemmed), and tall shrubby salvias. The best way is to take the cutting with a heal. Do this by gently breaking the shoot off the main stem so a small chunk of the main stem stays attached to the shoot. 

Divison

Division is ideal for herbaceous salvias that form clumps on the base or plants that increase their size from underground stems. Do it after winter has passed and the danger of frost is gone, when you see new shoots appearing. 

Begin by gently digging up the clump or tapping it out of its pot. Use a sharp knife or spade to slice the clumps in half or quarters, depending on size. Ensure each divided section has enough shoots and roots to thrive and a good amount of new growth.

Remove dead or damaged stems, shoots, and roots from the divided plant. Next, apply a rooting powder to the cut area and place it in its new position or pot. Fill the pot with soil, and firmly tamp down to secure the roots. This should result in 2-4 healthy new plants.

Layering

Layering is a simple and effective method for propagating salvias that spread along the ground or produce long, trailing stems that can be carefully bent down to the ground.

Some gardeners prefer to lightly wound or nick the stem, which can stimulate root growth. Others may cover a section of stem with soil or mulch, allowing it to develop roots.

Another method is to bury the nodes or "elbows" of the stem, where they naturally produce roots when they come into contact with the ground. This approach allows the plant to take root without further intervention."

When the stem is well rooted, it can be cut and potted up or planted in the garden.

Although salvia plants are low maintenance, they are not entirely immune to disease. One common problem is powdery mildew, which is more prevalent in humid climates. It causes a powdery wight mold coating on the leaves.

To prevent this, remove the affected parts of the plant to prevent the mold from spreading and avoid watering for a few days. Allow the soil and leaves to dry out, and ensure there is enough circulation of fresh air to prevent thermal stress on plants. 

Additionally, fungal diseases like rust and leaf spot can spread quickly through garden beds. Crowded, wet conditions and overhead watering cause the black spot to flourish. You should remove infected plant material and treat it with fungicide. 

Salvia ‘Amistad’

Height x Spread: 1.2m x 50cm

Amistades are often the go-to ornamental plants for many gardeners because of their large and spiky flowers that bloom from summer to autumn. It keeps flowering even after the first frost arrives, providing a much-needed food source for late-season pollinators.

They are particularly floriferous, bearing unusually large, deep purple flowers with almost-black calyces and stems. The petals have a soft, velvety texture, making them a prized choice for cut arrangements. Bees are also drawn to its nectar-rich blooms. 

Salvia nemorosa

Height x Spread: 50cm x 50cm

Salvia nemorosa, commonly known as violet sage or woodland sage, is a bushy upright perennial revered for its glowing dark purple flower stems and stunning bright violet-blue flowers appearing in late spring or early summer. They last for weeks and add vibrancy to perennial borders, butterfly gardens, and cottage gardens. It combines beautifully with daylilies or roses.

Salvia x jamensis ‘Hot Lips’

Height x Spread: 60cm x 90cm

Salvia ‘Hot Lips’ is a striking and evergreen shrubby salvia with brilliant bi-colored red and white flowers that bloom from early summer to frost. It gets its name from the large, scented, and open-mouthed flowers. They can tolerate partial shade, but for the best flower, full sun is best. 

This charming variety is ideal for planting near a seating area or pathway, allowing you to appreciate its lovely blooms and fragrant leaves up close. Its attractive flowers are also a magnet for bees and other pollinators, making it a great choice for attracting wildlife to your garden.

Salvia patens 'Cambridge Blue'

Height x Spread: 75cm x 50cm

Cambridge Blue salvias are a breathtaking perennial that bears azure-blue flowers reminiscent of the vibrant hues found in the gentian flower. The flowers contrast beautifully with the deep green foliage, making it an excellent choice for adding interest to smaller garden spaces. 

Apart from the flowers, this variety of salvia is known for its generous blooming period lasting from late spring through summer, ensuring your garden remains adorned with captivating blue flowers.