Nuttall's Milkvetch

Astragalus nuttallii

Native to:
United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Fabaceae
Genus:
Astragalus
Species:
Astragalus nuttallii
USDA Symbol:
ASNU5

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb
Height:
40 cm
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
apr,may,jun
Bloom Colors:
purple, white

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Caterpillars:
★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

Pollen Specialist Bee Keystone:
★★★☆☆ Native pollen specialist bee species supported by this genus (NWF)

Host Plant for Caterpillars

Western Tailed-Blue (Everes amyntula)

Garden & Ecology Notes

Wildlife Value:
bees, native pollinators
Deer Resistant:
Yes
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Tolerates fire and often increases in burned prairies. Resprouts from taproot after top growth is removed.

Soil Requirements

Soil Type:
sandy, well-drained, nutrient-poor soil
pH:
6.0 - 8.0 (neutral to slightly alkaline)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
Prefers open, sunny locations in its native range.

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Scarification:
Seed coat scarification required before sowing
Germination Time:
14–30 days
Notes:
Scarification improves germination rates. Hard seed coat typical of legumes benefits from mechanical or chemical scarification.

The above propagation data sourced from Claude AI

Pre-treatment: Seeds are soaked in water for 24 hours prior to sowing. Stratification has not been tried but may enhance germination.

Establishment: Seeds are collected between August 1st and September 30th. Mature legume pods are dry at maturity. A. nuttallii is found in dunes and bluffs along the ocean in coastal strand communities; from 10 to 300 feet elevation; from Monterey Bay south to Point Conception, California.

Source: npn.rngr.net

ORGHPS Germination Guide: Put in deep pot; protect from damping off

Source: Ontario Rock Garden & Hardy Plant Society