Douglas' Knotweed

Polygonum douglasii

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Polygonaceae
Genus:
Polygonum
Species:
Polygonum douglasii

Growth Characteristics

Life Cycle:
Annual
Growth Habit:
Forb/herb
Height:
2-3 ft
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
jun, jul, aug, sep, oct
Bloom Colors:
White, Pink, Green

Native Range

United States: Arizona, California, Colorado, Iowa, Idaho, Maryland, Maine, Michigan, Minnesota, Montana, North Dakota, Nebraska, New Hampshire, New Mexico, Nevada, New York, Oregon, South Dakota, Utah, Vermont, Washington, Wyoming, Canada: Alberta, British Columbia, Manitoba, Ontario, Quebec, Saskatchewan

Host Plant for Caterpillars

Epidemia helloides, Epidemia mariposa, Epidemia nivalis

Soil Requirements

Soil Type:
sandy, well-drained, nutrient-poor soil
pH:
5.5 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
Commonly found in disturbed areas and open habitats.

Germination Information

Pre-treatment: Seeds are placed in cold moist stratification for 60 days.

Establishment: P. douglasii is found from British Columbia to Colorado. There are 7 recognized botanical varieties. Germination was greater in light than on dark.

Source: npn.rngr.net