How to Grow Salvia x superba — Perennial Blue Salvia

Perennial blue salvia

Perennial blue salvia, Salvia x superba, bear slender, terminal racemes of bright violet or purple flower from midsummer to early autumn.

Perennial blue salvia is a clump-forming, erect, branched perennial with lance-shaped mid-green leaves. It grows up to 3 feet (91cm) tall. It grows best in Zones 5 to 9.

Get to Know Perennial Blue Salvia

  • Plant type: Perennial
  • Growing Zones and range: Zones 4-8
  • Hardiness: Hardy to -20°F (-29°C)
  • Height and width: 12-36 inches (30-91cm) tall; 12 to 24 inches (30-61cm) wide
  • Foliage: Lance-shaped to oblong, scalloped, mid-green leaves to 4 inches long
  • Flowers: 2-lipped, the upper lips erect and hooded, the lower one 2-toothed and more spreading on spikes
  • Flower colors: Bright violent or purple
  • Bloom time: Early to midsummer
  • Uses: Beds, borders
  • Garden companions: Shasta daisies, yarrow
  • Common name: Perennial blue salvia
  • Botanical name: Salvia x superba
  • Family: Lamiaceae
  • Origin: Distributed worldwide in temperate and tropical regions

Where to Plant Perennial Blue Salvia

  • Plant perennial blue salvia in full sun to light shade.
  • Grow perennial blue salvia in humus-rich, well-drained soil.

Salvia Uses and Companions

  • Plant Salvias in beds and borders and containers.
  • Salvias are effective in a sunny border, light woodland, or wildflower meadow.
  • Many Salvia species attract bees.
  • Good garden companions for Salvia include Achillea, Coreopsis, Gazania, Gerbera jamesonii, Heuchera, Potentilla, Rudbeckia.
Perennial blue salvia, Salvia superba
Perennial blue salvia, Salvia superba

When to Plant Perennial Blue Salvia

  • Set perennial blue salvia in the garden in spring or fall.
  • Start seed indoors 8 weeks before the last frost.
  • Sow seeds outdoors after the danger of frost has passed.
  • Set plants started indoors into the garden after the last frost when the weather has settled.

Planting and Spacing Perennial Blue Salvia

  • Start seed indoors in flat or six-packs; cover seeds with 1/8 inch of soil.
  • Water and keep seed warm 65° to 75°F (18°-24°C); seeds germinate in about 14 days, sometimes less. Grow in bright sunlight or a few inches below fluorescent light.
  • Sow seed outdoors in drills about 2 inches (5cm) deep; plant seeds 2 inches (5cm) and cover with 1/8 inches soil.
  • Thin or transplant seedlings when they are about 4 inches (10cm) tall.
  • Space salvias in the garden 8 to 36 inches (20-91cm) apart depending on the variety.
Perennial blue salvia, Salvia superba
Perennial blue salvia, Salvia superba

How to Water and Feed Perennial Blue Salvia

  • Keep the soil evenly moist; perennial blue salvia needs moderate moisture.
  • Fertilize perennial blue salvia every 6 weeks with an all-purpose fertilizer or work in a slow-release fertilizer in spring.

Perennial Blue Salvia Care

  • Mulch around perennial blue salvia to conserve soil moisture.
  • Trim off spent blooms to promote additional blooms.
  • Tall varieties may need staking.
  • Perennial blue salvia is commonly pest and disease-free.
  • Perennial blue salvia can be divided in spring.

Perennial Blue Salvia Propagation

  • Grow annual salvias from seed; grow perennials from seed or by division.
  • Seeds germinate in 12 to 15 days at 70°F (21°C); soak seeds of Salvia splendens to speed germination.
  • Sow seeds indoors 4 to 6 weeks before the last frost for early blooms.
  • All salvias can be grown from stem cuttings. Take stem cuttings during warm weather. Root under high humidity in damp potting medium.

Perennial Blue Salvia Varieties to Grow

  • ‘East Friesland’ is purple
  • ‘Mainacht’ is violet-blue.
  • ‘Maynight’ is bright blue.

Also of interest:

How to Grow Salvias

How to Grow Annual Blue Salvia — Salvia

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