Halfmoon Milkvetch

Astragalus wootonii

Native to:
Mexico, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Fabaceae
Genus:
Astragalus
Species:
Astragalus wootonii
USDA Symbol:
ASWO2

Growth Characteristics

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

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

Pima granitella

Garden & Ecology Notes

Wildlife Value:
bees, native pollinators
Deer Resistant:
Yes

Soil Requirements

Soil Type:
sandy, well-drained, nutrient-poor soil
pH:
6.5 - 7.5 (neutral to slightly alkaline)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to arid regions, prefers open areas

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Scarification:
Seed coat scarification required before sowing
Germination Time:
14–45 days
Notes:
Hard seed coat typical of Astragalus requires scarification. Some seeds may exhibit prolonged dormancy and germinate sporadically over multiple seasons.

The above propagation data sourced from Claude AI

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).; then Scarify, then cold-moist stratify for 60 days.

Source: Claude AI

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

Source: Ontario Rock Garden & Hardy Plant Society