The primary food source for Monarch Butterfly larvae, Common Milkweed are typically found growing in disturbed sites. They don’t compete well against other vegetation, although they can create formidable colonies through rhizome division and seeds.
Asclepis syriaca (Common Milkweed)
Hardiness Zones: 3-9
Height: 60-90 centimeters (24-36 inches, rarely to 1.8 meters (6 feet)) tall
Diameter: 22-30 centimeters (9-12 inches) wide
Growth Rate: moderate
Root System: extensive lateral roots with rhizomes, moderately deep
Tolerates: dry soil, rocky soil, drought, erosion herbivores (deer)
Problems (major): none
Problems (minor): These don’t compete well with other vegetation, so they live mostly in disturbed sites.
Poisonous: moderate, edible if carefully and thoroughly cooked
Soil requirements: prefers well-drained soils, light/sandy to medium/loamy
Air requirements: not sufficiently researched
Watering requirement: low to moderate
Sun requirement: full sun
Leaf shape: long ovate or oblong, light green with red venation
Leaf size: to 20 centimeters (8 inches) long
Flower structure: pendulous umbels with white, pink, or purple flowers
Flowering frequency: June-August
Fruits: oddly shaped, greenish when new to gray when mature, open in September, bluntly spiky
Seeds: white lacy strings/wings, light to dark brown seed
Subterranean storage organ: rhizome
The rhizomes spread rapidly, and self-seeding may produce colonies. White hairs are present on the stems and leaves and
very noticeable on seed pods/fruits.
These plants are the primary food source for monarch butterfly larvae.
Immature seed pods
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