Astello indigo is a hybrid hyssop in the mint family (Lamiaceae) and grows vigorously to 20 inches tall in a compact clump. Plant in full to part sun in well-drained soils. It is drought and heat-tolerant and disease-resistant. Poorly drained soils and wet wet winter feet will do it in. Use a container or raised bed if needed. The deep green leaves are arranged oppositely on square stems and smell a little like rootbeer when crushed. The upright spikes are fully covered with deep indigo-blue flowers that exude a fresh minty scent that attracts butterflies and bees Grow this plant in containers, a pollinator garden, in the border and mass plantings. The plant provides vertical interest to the garden In colder climates, it can be grown as an annual. It provides a long season of blooms and attracts many pollinators to the landscape. Insects, Diseases, and Other Plant Problems: Crown rot in wet soils. No significant problems. Watch for Spider mites, thrips, aphids, whitefly, and slugs. More information on Agastache .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Fills a similar nicheAgastache 'Blue Fortune'Buddleja Lo & Behold® 'Blue Chip Jr.'Salvia nemorosa
Full plant profile
Growing Conditions
Plant type
Herbaceous Perennial; Perennial
Life cycle
Perennial
USDA zones
6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Loam (Silt); Sand
Soil pH
Acid (<6.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Occasionally Dry
Available space
Less than 12 inches; 12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 0 ft. 6 in. - 1 ft. 8 in. | Width: 1 ft. 2 in. - 1 ft. 8 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Erect
Texture
Medium
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf margin
Serrate
Leaf value
Fragrant
Hairs present
No
Leaf detail
Bright green leaves are slightly serrated and have a rootbeer fragrance.
Flower color
Blue; Purple/Lavender
Flower value
Fragrant; Good Cut; Good Dried; Long Bloom Season
Flower form
Spike
Flower shape
Lipped; Tubular
Flower size
< 1 inch
Flower detail
Indigo blue flowers have a minty fragrance from summer through fall. Produces many small tubular blooms on tall spikes. Blooms are blue surrounded by deep purple bracts.
Bloom time
Fall; Summer
Fruit type
Nut
Fruit detail
Dry nutlet
Stem color
Green
Stem detail
Strong square green stems
Wildlife & Ecology
Native status
Unknown
Wildlife value
Flowers attract butterflies, hummingbirds, birds, and bees.