How to Grow Locoweed
Locoweed
Astragalus and Oxytropis species
shrubLocoweed is a genus of toxic plants native to arid and semi-arid regions of North America, characterized by purple, pink, yellow, or white flower spikes and compound leaves. The plant accumulates alkaloid compounds, particularly swainsonine, that cause neurological damage in livestock and wildlife that consume it. Locoweeds are adapted to harsh, drought-prone environments and are generally not cultivated intentionally.
When should you plant Locoweed in your zone?
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Example Locoweed timeline · Pittsburgh, PA (Zone 6b)
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Plant Locoweed
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Locoweed
Late summer into fallBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Locoweed dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 4-9, depending on species; naturally occurs in arid western regions
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Get my Locoweed timeline →Growth Stages
Seed Germination
2-4 weeks or longerSeeds are small and hard-coated; germination is slow and sporadic even after scarification
Scarify seed coat or soak in warm water for 24 hours before sowing. Start indoors or direct sow in fall for cold stratification. Keep soil barely moist until sprouts appear.
Seedling & Establishment
4-8 weeksSmall compound leaves emerge; plant grows slowly, developing a deep taproot system
Minimize disturbance to avoid damaging the taproot. Do not transplant unless necessary. Keep soil moderately dry. Thin seedlings to proper spacing early.
Vegetative Growth
Several monthsPinnate compound leaves fill out; plant develops bushy form and strengthens root system
No fertilizer needed; allow drought stress to develop deep roots. Mulch lightly to retain some moisture and prevent weed competition. Most plants remain vegetative in year one.
Flowering
4-6 weeksDense flower spikes in purple, pink, yellow, or white appear, typically in late spring to early summer of year two
Do not deadhead if you want seeds to develop naturally. Flowers attract bees and other pollinators. Allow plants to complete flowering cycle.
Seed Production & Dormancy
4-8 weeks to maturityFlowers produce seed pods; plant may self-seed in suitable conditions. Plants may die back in hot summers or persist as perennials depending on species
Allow seed pods to mature on plant before harvesting if seed collection is desired. Let ripe pods dry completely. Collect seeds for propagation or allow natural reseeding.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Remove and destroy infested seed pods before beetles emerge; no practical chemical control for home gardeners; mostly a concern only in seed production
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Ensure well-draining soil; avoid overwatering; provide good air circulation; remove affected plants immediately
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Spray with water to dislodge; use neem oil or insecticidal soap if severe; encourage natural predators
Uses
Native Plant Restoration
WildlifeLocoweed is used in native plant restoration and xeriscaping projects in western North America to support grassland and semi-arid ecosystems. It provides early-season forage for native wildlife that have evolved tolerance to its alkaloids. [source]
Ornamental Landscape Plant
HouseholdThe striking flower spikes in various colors make locoweed an interesting ornamental choice for native plant gardens, rock gardens, and drought-tolerant landscapes in western regions. Requires minimal maintenance once established. [source]
Ethnobotanical & Toxicological Interest
MedicinalHistorically, some Native American cultures used locoweed species in small, controlled amounts for ceremonial or medicinal purposes, though the practice is dangerous. Modern interest is primarily academic and toxicological. [source]
Livestock Poisoning & Ecological Study
WildlifeLocoweed is significant in animal husbandry as a cause of poisoning in livestock ('locoism'). Its presence in rangelands is studied to understand plant-animal interactions and ecosystem health. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Locoweed is not typically harvested for any culinary or medicinal purpose due to its toxicity. Seed collection: Allow pods to dry on plant until they split open naturally. Collect mature, papery pods and extract seeds. Seeds are viable for several years if stored cool and dry. Do NOT harvest for human or animal consumption.
Fun Facts
- 🌱 The term 'loco' (Spanish for 'crazy') comes from the neurological effects the plant causes in livestock, which exhibits strange and destructive behavior after consuming locoweed, including the disease state called 'locoism'.
- 🌱 Locoweed plants accumulate the alkaloid swainsonine, which disrupts the nervous system by inhibiting certain enzymes. Some insects and native herbivores have evolved resistance or tolerance to this toxin.
- 🌱 Locoweed was a significant challenge to westward expansion and cattle ranching in the 19th century, causing major economic losses and inspiring early botanical toxicology research.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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