Consolida–commonly called larkspur looks very much like delphinium; they are members of the same genus. Larkspur has spurred, delphinium-like flower stalks in pink, blue, or white rising above feathery, softly downy, mid-to dark green leaves. Larkspur is a favorite choice for cottage gardens and annual borders.
Larkspur is the name commonly applied to the annual species of Delphinium. There is a minimal structural distinction between larkspur and delphinium; delphiniums are perennials and the flower spikes are larger; larkspur is smaller, of looser form, and less imposing.
Blue predominates in the annual larkspurs, but the colors range from white through pink and blue to deep purple; the wand-like spikes or loose racemes bear many flowers about the feathery, soft green foliage.
Annual larkspur is easily raised from seed. Seed can be started indoors in early spring or in the open after the soil has warmed in late spring. Larkspur can also be sown in fall in mild-winter regions.
Get to Know Larkspur
- Plant type: Annual
- Growing Zones and range: Zone 4 to 10
- Hardiness: Tender’ plants die out in summer heat and humidity
- Height and width: 12 to 60 inches (30-152cm) tall; 8 to 12 inches (20-30cm) wide depending on the variety
- Foliage: Feathery, softly downy, mid- to dark-green leaves are palmate with many leaflets
- Flowers: 7-petaled flowers are 1.5 inches (38mm) wide on racemes or panicles
- Flower colors: Intense blue flowers also whites. pinks, rose, salmon, and carmine.
- Bloom time: Spring to early-summer blooms in Zones 8-10; summer blooms in Zones 4-7
- Uses: Informal gardens, cottage gardens; best when planted in groups of 20 plants or more.
- Common name: Rocket Larkspur, annual delphinium, rocket
- Botanical name: Consolida ambigua
- Family: Ranunculaceae
- Origin: Western Mediterranean region to Central Asia
Where to Plant Larkspur
- Plant Larkspur in full sun in Zones 2-7; plant in light shade in Zones 8-11.
- Grow larkspur in humus-rich, well-drained soil; larkspur will grow in average garden soil.
- Larkspur prefers a soil pH of 7.0-7.5.
- Larkspurs provide excellent foliage and bloom for the middle and back of a border.
- Larkspur’s pastel colors are set off to advantage against a dark background of evergreens.
- Dwarf varieties can provide color at the front of a border.
- Larkspur is excellent for cutting.
When to Plant Larkspur
- Sow seed indoors 8 to 10 weeks before the last frost in spring.
- Sow Larkspur directly in the garden from early spring to mid-spring as soon as the soil can be worked; larkspur can also be planted in fall.
- In Zones 9-11, seeds can also be sown in fall for winter or early spring bloom.
- Repeated sowings at 3-week intervals lengthen the bloom season.
Planting and Spacing Larkspur
- Sow seed indoors in six-packs or flats in sterile seed starting mix; set the sown pots in the refrigerator 2 weeks before moving them to a warmer (50°-55°F/10°-12.8°C) place for germination, which takes 2 to 3 weeks.
- Sow seed outdoors in evenly prepared soil.
- Space larkspur 8 to 12 inches (20-30cm) apart.
How to Water and Feed Larkspur
- Keep Larkspur well-watered but avoid wetting leaves.
- Fertilize larkspur with an all-purpose fertilizer in spring and midsummer.
- Larkspur reseeds freely. Plants are easy to remove
- Some Larkspur varieties will grow tall and lean on other plants. Stake plants as needed.
- Shelter larkspur from the wind.
- Deadhead spent blooms to prolong bloom; allow some flower to set seed if you want them to self-sow for future blooms.
Larkspur Pests and Diseases
- Larkspur resists pests and diseases.
- Larkspur is propagated by seed. Seeds germiante in 10 to 20 days. Chill the seeds for 7 days to improve germination.
- Lightly cover seeds with soil then firm them in with the palm of your hand.
- Remove spent plants and shake them upside down to scatter seeds.
Larkspur Varieties to Grow
- Consolida ajacis, formerly C. ambigua. Grows 12 to 48 inch (30-121cm) tall; ferny, palmate leaves; 6 to 24 inches (15-61cm) flower spikes in shades of blue, violet, lavender, white, or pink. Cultivars include: ‘Dwarf Hyacinth Mixed’ is a blue, white, and pink mix; ‘Frosted Skies’ has white flowers with blue edges, grows to 18 inches tall; ‘Early Bird Hybrids’ grow to 20 inches tall; ‘Sublime Mix’ is 3 to 4 feet tall; ‘Giant Imperials’ grow 4 to 5 feet tall.