With its elegant, bi-colored blooms in rich shades of midnight and sapphire, black and blue salvia (Salvia guaranitica) brings striking beauty to gardens. Growing black and blue salvia from seed allows you to fill your landscape economically with these exotic-looking flowers that attract admiring looks and hungry hummingbirds alike.
Black and blue salvia, also called anise-scented sage, is a herbaceous tender perennial grown as an annual in zones 7-10. This fast-growing salvia reaches 4-6 feet tall and 3 feet wide at maturity, with multi-branching purple stems.
The tubular flowers bloom on tall spikes, with petals in vivid iridescent blue and sepals (the outer ring) in deep blackish-purple. The two-tone effect is eye-catching. Bloom time is midsummer through fall. The flowers also emit a lovely anise scent.
This Brazilian native thrives in heat and needs full sun. It enjoys moist, well-drained soil and moderate watering. Give it room to reach its full size in borders. Containers should be at least 18-24 inches deep.
When and How to Plant Black and Blue Salvia Seeds
Black and blue salvia is easy to grow from seed. Start seeds 8-10 weeks before your last spring frost indoors or in a greenhouse.
You can sow seeds directly in pots or flats filled with seed starting mix. Cover seeds lightly, about 1⁄4 inch deep. Maintain a soil temperature of 70-75°F for fastest germination in 10-15 days.
Once seedlings emerge, grow them on at 65-70°F with bright light. Harden off plants for 7-10 days before transplanting into the garden after all danger of frost has passed. Space plants 18-24 inches apart.
Growing Black and Blue Salvia from Seeds
Follow these tips for success in growing black and blue salvia from seeds:
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Use fresh seed each year for best germination
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Optionally pre-chill seeds for 5 days before planting
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Sow seeds in sterile seed starter mix
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Cover seeds lightly with 1⁄4 inch of mix
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Keep soil moist but not saturated while germinating
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Use bottom heat and grow lights for optimal conditions
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Transplant into garden after hardening off seedlings
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Give plants plenty of space to reach mature size
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Grow in full sun with fertile, well-drained soil
Caring for Black and Blue Salvia Plants
Once established, black and blue salvia requires only basic care:
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Water regularly, allowing soil to dry out slightly between waterings
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Apply liquid fertilizer every 2-3 weeks during growing season
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Stake tall stems as needed to prevent flopping
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Prune back by 1/3 after initial summer bloom to encourage re-blooming
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Mulch around plants to conserve moisture and reduce weeds
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Lift tubers or take cuttings to overwinter in zones 8 and below
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Provide good air circulation and avoid wetting foliage
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Remove spent flowers and any diseased foliage promptly
Troubleshooting Problems with Black and Blue Salvia
Black and blue salvia is relatively trouble free, but may experience:
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Leggy, weak seedlings from insufficient light or overcrowding
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Leaf spot diseases from poor air circulation and wet foliage
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Failure to bloom from too much nitrogen, overcrowding, or inadequate sunlight
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Flopping from tall top-heavy stems
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Root rot from overwatering or poor drainage
Adjust growing conditions and care as needed to avoid these issues.
Tips for Using Black and Blue Salvia in Gardens
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Grow as a backdrop to smaller plants
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Underplant with lower growers like violas or dahlias
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Mass in borders or island beds for bold color impact
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Highlight in containers on decks or patios
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Pair with silver, white, or yellow flowers for contrast
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Attract hummingbirds, bees, and butterflies
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Cut flower spikes to bring indoors
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Alternate with red or purple salvias for extended bloom seasons
Enjoying Stunning Black and Blue Blooms
With its richly saturated midnight and sapphire blooms on elegant stalks, black and blue salvia adds incredible beauty to gardens. By starting this exotic-looking plant from seed, you can easily and economically fill borders, beds, and containers with its vibrant towers of color. Give black and blue salvia plenty of sun, space, and moderate care, and you’ll be rewarded with a spectacular display that lasts from midsummer into fall.
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FAQ
Can black and blue salvia be grown from seed?
Does Black and Blue Salvia come back every year?
Are salvias hard to grow from seed?
What month do you plant salvia seeds?
What is a black and blue salvia?
The description of these plants has been written based on numerous outside resources. One of the most popular salvias, Salvia guaranitica ‘Black and Blue’ (Anise-Scented Sage) is a particularly attractive perennial featuring showy spikes of large, deep cobalt blue flowers, 2 in. long (5 cm), emerging from black calyces.
Is Salvia guaranitica a perennial?
Salvia guaranitica black and blue is an attractive perennial that bears cobalt blue flowers and either light green or black calyces. Also known as “Black and Blue” Salvia, the cultivar belongs to the Salvia genus of evergreen shrubs. Native to southern South America, especially Brazil, the plant height is 6′ feet tall and is grown as an annual.
How tall does black and blue salvia grow?
Black and Blue salvia ( Salvia guaranitica “Black and Blue”) is an anise-scented sage cultivar which may grow up to 6 feet tall in ideal growing conditions, producing 15-inch spikes of deep blue, two-lipped flowers from mid-summer into fall.
Do black & blue salvia plants have mildew?
You may want to skip it entirely, as black and blue salvia can handle the infestations of most pests. These plants can also suffer from downy mildew and powdery mildew due to poorly drained soils and high humidity. The best way to prevent this is by pruning for air flow and removing weeds to promote aeration.
What is Salvia guaranitica black and blue?
Salvia guaranitica black and blue is a species within the Salvia genus and belongs to the Lamiaceae family. This plant can be biennial, annual, evergreen, or herbaceous. It is known for its simple or pinnately-lobed, fragrant pale to dark green leaves and two-lipped blue flowers on spikes.
Where to buy salvia seed?
So we are living in a world where BC Seeds is teh only place in the world to buy high quality salvia seed. Salvia cuttings are found in most places around the world. If you dig hard enough and deep enough you’ll eventually make a connection to someone you will share a cutting with you.