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.
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.
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.
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