Sand Plum
Prunus angustifolia watsonii

Family: Rosaceae

What it is like

Prunus angustifolia watsonii is a deciduous Shrub growing to 3 m (9ft 10in). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from April to May. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 3

Where it is found

Thickets in low sandy places near streams.

Central N. America.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 4

Fruit - raw or cooked. An acid taste, the fruit is often used for making preserves, pies etc. A reasonable size, it is about 14mm x 9mm and contains a single large seed. Seed - raw or cooked. Do not eat the seed if it is too bitter - see the notes above on toxicity.

Seed: includes nuts, cereals, peas and beans.

Medicine

Rating: 1

Although no specific mention has been seen for this species, all members of the genus contain amygdalin and prunasin, substances which break down in water to form hydrocyanic acid (cyanide or prussic acid). In small amounts this exceedingly poisonous compound stimulates respiration, improves digestion and gives a sense of well-being.

Other

Rating: 2

A green dye can be obtained from the leaves. A dark grey to green dye can be obtained from the fruit. Wood - heavy, rather soft, not strong. It weighs 43lb per cubic foot and is of little commercial value.

Dye: Plants that provide dyes.

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

Scented Plants: Plants noted for their scent

How it is grown

Thrives in a well-drained moisture-retentive loamy soil. Prefers some lime in the soil but is likely to become chlorotic if too much lime is present. Succeeds in sun or partial shade though it fruits better in a sunny position. Unlike the type species, this sub-species thrives in Britain. The flowers, which appear just before the leaves unfold, have a refreshing fruity scent. Most members of this genus are shallow-rooted and will produce suckers if the roots are damaged. Plants in this genus are notably susceptible to honey fungus. 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 running thicket former forming a colony from shoots away from the crown spreading indefinitely. The root pattern is suckering with new plants from underground runners away from the plant.

Propagating it: Seed - requires 2 - 3 months cold stratification and is best sown in a cold frame as soon as it is ripe. Sow stored seed in a cold frame as early in the year as possible. Protect the seed from mice etc. The seed can be rather slow, sometimes taking 18 months to germinate. Prick out the seedlings into individual pots when they are large enough to handle. Grow them on in a greenhouse or cold frame for their first winter and plant them out in late spring or early summer of the following year. Cuttings of half-ripe wood with a heel, July/August in a frame. Softwood cuttings from strongly growing plants in spring to early summer in a frame. Layering in spring.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade;

Habit: Shrub

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Although no specific mention has been seen for this species, it belongs to a genus where most, if not all members of the genus produce hydrogen cyanide, a poison that gives almonds their characteristic flavour. This toxin is found mainly in the leaves and seed and is readily detected by its bitter taste. It is usually present in too small a quantity to do any harm but any very bitter seed or fruit should not be eaten. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.

Its other names

Local names

Synonyms

P. watsonii. Sarg.