Photo: PkravchenkoCC BY-SA 3.0via Wikimedia Commonsresized / cropped
Long Milk-vetch Plant Care
Astragalus praelongus E.Sheld.
Updated · Sources · How we source care data
This plant boasts delicate, silver-green leaves that form a dense mat on the ground. Originating from the Western United States, Astragalus praelongus is highly sought after by plant collectors for its unique foliage texture and ability to thrive in dry, rocky environments.
Every 7–10 days
Full sun to partial shade
60–80°F
40–60%
At a glance
How do you care for Long Milk-vetch?
Plant Long Milk-vetch in full sun to partial shade (USDA zones 5a–8b) and water a young shrub every 7–10 days until it is established. It tolerates temperatures of 60–80°F (16–27°C). Fertilize it every 8 months during the growing season.
Where Is the Long Milk-vetch Native To?
What Is the Long Milk-vetch?
Long Milk-vetch (Astragalus praelongus) belongs to the Fabaceae family within the Astragalus genus. Long Milk-vetch is native to the Colorado Plateau and Canyonlands region of the southwestern United States. Long Milk-vetch is also known as Astragalus pattersonii, Astragalus procerus, Astragalus rothrockii.
Long Milk-vetch displays a low spreading ground cover growth habit, reaching up to 0.5 ft tall with a spread of approximately 2 ft. Long Milk-vetch produces small pea-like flowers in shades of purple, pink, or white.
Leaf size: approximately 1 inches.
How Often Should You Water a Long Milk-vetch?
Water a young or newly planted Long Milk-vetch every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–10 days
Until established; then in dry spells
What Light Does the Long Milk-vetch Need?
Long Milk-vetch thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Long Milk-vetch Prefer?
Astragalus praelongus tolerates temperatures of 60–80°F. Long Milk-vetch prefers humidity levels of 40–60%.
Temperature
60–80°F
Humidity
40–60%
What Soil Mix Works Best for a Long Milk-vetch?
Well-draining sandy soil mix with added perlite for extra drainage. Good drainage is essential for Long Milk-vetch to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Long Milk-vetch?
Feed Long Milk-vetch every 8 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.
Stop feeding by late summer so new growth can harden before winter.
Fertilizing
Every 8 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
Where Should You Plant a Long Milk-vetch?
Choose a spot with full sun to partial shade and well-draining sandy soil mix with added perlite for extra drainage. Avoid low spots where water collects after rain.
Long Milk-vetch is suited to USDA Zone 5a – 8b.
Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a Long Milk-vetch?
Long Milk-vetch can spread to about 2 ft (0.6 m) and reach about 1 ft (0 m) tall. Space plants about 2 ft (0.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the plant spacing calculator.
How Do You Prune a Long Milk-vetch?
Prune Long Milk-vetch while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.
How Do You Care for a Long Milk-vetch in Winter?
Long Milk-vetch is hardy down to USDA zone 5a, so once established it can stay outdoors through winter in that zone and warmer ones.
Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.
Young and container-grown shrubs need extra protection: roots in a pot freeze much more easily than roots in the ground.
How Do You Propagate a Long Milk-vetch?
Long Milk-vetch can be propagated through seeds, division of root ball. Similar propagation techniques also apply to aragallus acutirostris plant care, which shares the same genus.
Is the Long Milk-vetch Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Long Milk-vetch, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Long Milk-vetch?
Long Milk-vetch is susceptible to aphids, spider mites, leafhoppers. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Long Milk-vetch Need?
Long Milk-vetch grows outdoors in USDA Zone 5a – 8b. It survives winters down to planting zone 5a. Long Milk-vetch is native to the Colorado Plateau and Canyonlands region of the southwestern United States.
Hardiness Zone
Zone 5a – 8b
Keep exploring plants
Long Milk-vetch is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Astragalus genus — compare its care with other Astragalus species on PlantoScan.
Astragalus is part of the Fabaceae plant family — browse all Fabaceae genera and species.
Long Milk-vetch thrives in bright light and direct sun — see other bright-light plants.
More Astragalus Species
Other Astragalus species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Astragalus praelongus E.Sheld., family Fabaceae (first published in Minnesota Bot. Stud. 1: 23 (1894)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Long Milk-vetch, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Pkravchenko, CC BY-SA 3.0, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 5a – 8b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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