Species Williams' Milkvetch
purple-white flowers with green leaves and stems

Williams' Milkvetch

Astragalus williamsii

William's Milkvetch (Astragalus williamsii) is a deciduous perennial flowering plant native to Wyoming. It has wiry leafy stems and grows in clumps up to 1 metre tall and wide. Its small yellow-green flowers are clustered in heads and have a sweet scent. They bloom in the spring and attract pollinators such as bees and butterflies. Its small, smooth, grey-green oval-shaped leaves are arranged alternately on the branches. The seeds are eaten by small animals like birds and mice. Its strong root system helps retain soil and can even help to stabilize soils on slopes. Williams' Milkvetch is drought tolerant and is found in open meadows and grasslands.

Watering:

Minimal

Hardiness Zone:

Sun:

full sun,part shade

Leaf:

Yes

Leaf Color:

green,yellow

Growth Rate:

Low

Salt Tolerant:

Yes

Care Level:

Medium

watering

Water Santa Barbara Milkvetch plants regularly and deeply, but avoid over-watering. This species of plant is drought tolerant, so opt for occasional, deeper waterings rather than frequent, shallow ones. Aim to water newly planted Milkvetch twice a week for the first 2 months, then you can adjust to 1-2 times per month depending on the soil and climate conditions. As the plant gets established, it will become less reliant on frequent water. If the climate is particularly dry, you may need to water more frequently. In the hot summer months, Santa Barbara Milkvetch may need to be watered twice per month or more.

sunlight

The Santa Barbara milkvetch (Astragalus trichopodus var. lonchus) typically grows in full sun or partial shade. For optimum growth, the species should receive at least 6 to 8 hours of direct sunlight each day. This species is not very tolerant of full shade and will not grow if deprived of sunlight. Thus, it is advisable to provide the plant with bright sunlight, especially during the growing season, in order to maximize its health and growth.

pruning

Pruning Santa Barbara Milkvetch (Astragalus trichopodus var. lonchus) should occur twice yearly, in early spring and late summer. Pruning in spring should be done lightly, focusing on only 1 or 2 stems at a time. In late summer, the plant should be cut back by 1-third and all dead or damaged stems should be removed. Pruning in late summer helps keep the plant compact and promotes healthy growth the following year. However, it is important to avoid excessive cutting, as this can cause physical stress on the plant.

⚠️ Perenual and its members cannot be held liable for any health issues that may arise from the information provided on the website or from using any of the plants found on the site. The information provided is intended to be used as general guidelines only.