Canadian Milkvetch, Shorttooth Canadian milkvetch, Morton's Canadian milkvetch
Astragalus canadensis

Family: Fabaceae or Leguminosae

What it is like

Astragalus canadensis is a PERENNIAL growing to 1 m (3ft 3in). See above for USDA hardiness. It is hardy to UK zone 8. It is in flower in July. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, Lepidoptera (Moths & Butterflies). It can fix Nitrogen. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers dry soil.

Height (m): 1

Where it is found

Shores and rich thickets. Rocky and sandy thickets in Texas.

Central and eastern N. America - Quebec to Saskatchewan, New York, Louisiana, Nebraska and Utah.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 3

Root - raw or boiled. They were often used in a broth. The roots are gathered in spring or autumn. Some caution is advised, if the root is bitter it could be due to the presence of toxic alkaloids.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 2

The root is analgesic and antihaemorrhagic. It can be chewed or used as a tea to treat chest and back pains, coughs and the spitting up of blood. A decoction of the root is used as a febrifuge for children. A poultice made from the chewed root has been used to treat cuts.

Analgesic: Relieves pain.

Febrifuge: Reduces fevers.

Haemostatic: Controls internal bleeding.

Other

Rating: 3

Nitrogen fixer.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

Nitrogen Fixer: Plants that fix nitrogen in the soil

How it is grown

Requires a dry well-drained soil in a sunny position. This species is not hardy in the colder areas of the country, it tolerates temperatures down to between -5 and -10°c. Plants are intolerant of root disturbance and are best planted in their final positions whilst still small. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby. Many members of this genus can be difficult to grow, this may be due partly to a lack of their specific bacterial associations in the soil. For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a runner spreading indefinitely by rhizomes or stolons.

Propagating it: Seed - best sown as soon as it is ripe in a cold frame. A period of cold stratification may help stored seed to germinate. Stored seed, and perhaps also fresh seed, should be pre-soaked for 24 hours in hot water before sowing - but make sure that you do not cook the seed. Any seed that does not swell should be carefully pricked with a needle, taking care not to damage the embryo, and re-soaked for a further 24 hours. Germination can be slow and erratic but is usually within 4 - 9 weeks or more at 13°c if the seed is treated or sown fresh. As soon as it is large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter, planting them out into their permanent positions in late spring or early summer, after the last expected frosts.

Best place to grow: Cultivated Beds;

Habit: Perennial

Hardiness: 7-10

Growth:

Soil: Light (sandy), medium

Shade: No shade

Moisture: Dry

Things to keep in mind

Many members of this genus contain toxic glycosides. All species with edible seedpods can be distinguished by their fleshy round or oval seedpod that looks somewhat like a greengage. A number of species can also accumulate toxic levels of selenium when grown in soils that are relatively rich in that element.

Its other names

Local names

Synonyms

A. carolinianus. L.