Polygonum douglasii
| Polygonum douglasii | |
| Light: |   |
| Moisture: |   |
| Soil pH: | 5.6-8.4 |
| Height: | 1' |
| Native to: | |
| Edible Rating: |  |
| Tea: | Yes |
 | |
Polygonum douglasii (common name: knotweed)
Propagation: Seed - sow spring in a cold frame. Germination is usually free and easy. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer if they have reached sufficient size. If not, overwinter them in a cold frame and plant them out the following spring after the last expected frosts.
Division in spring or autumn. Very easy, larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer.
Cultivation: We have very little information on this species and do not know if it is hardy in Britain, though judging by its native range it should succeed outdoors in most parts of the country. The following notes are based on the general needs of the genus.
Succeeds in an ordinary garden soil[1] but prefers a moisture retentive not too fertile soil in sun or part shade[2]. Repays generous treatment[1].
Plants seem to be immune to the predations of rabbits[3].
Range: N. America - Northwest Territory to British Columbia, south to Vermont, New Mexico and Oklahoma.
Habitat: Rocky slopes and dry soils all over N. America[4][5].
Edibility: Leaves - raw or cooked.
Seed - dried then ground into a powder and mixed with cornmeal or other cereals for making bread etc[6][7][8][9][10]. The seed is rather small and fiddly to utilize, it is enclosed in a dry papery hull[11].
Pollinators: Insects
Soil: Can grow in light, medium, and heavy soils.
Flower Type: Hermaphrodite
Known Hazards: Although no specific mention has been made for this species, there have been reports that some members of this genus can cause photosensitivity in susceptible people._x005F
Many species also contain oxalic acid (the distinctive lemony flavour of sorrel) - whil
Links
References
- ↑ 1.0 1.1 Chittendon, Fred. RHS Dictionary of Plants. Oxford University Press, 1951.
- ↑ Huxley, Anthony. The New Royal Horticultural Society Dictionary of Gardening. MacMillan Press, 1992.
- ↑ Thomas, Graham. Perennial Garden Plants. J. M. Dent & Sons, 1990.
- ↑ Lyndon, Merritt. Gray's Manual of Botany. American Book Co, 1950.
- ↑ Hitchcock, Leo. Vascular Plants of the Pacific Northwest. University of Washington Press, 1955.
- ↑ Uphof, Johannes. Dictionary of Economic Plants. Weinheim, 1959.
- ↑ Usher, George. A Dictionary of Plants Used by Man. Constable, 1974.
- ↑ Tanaka, Tyōzaburō. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing, 1976.
- ↑ Yanovsky, Elias. Food Plants of the North American Indians Publication 237. US Department of Agriculture.
- ↑ Moerman, Daniel. Native American Ethnobotany. Timber Press, 1998.
- ↑ Coffey, Timothy. The History and Folklore of North American Wild Flowers. Facts on File, 1993.