Native Milkweed for attracting and supporting Monarch Butterflies
Common Milkweed (Asclepias syriaca)
Monarch butterflies (Danaus plexippus) only lay eggs on plants in the milkweed family. The Milkweed host-plants are the only food Monarch caterpillars eat. Milkweed is no longer listed as an Ontario noxious weed.
Sap contains cardiac glycosides that are poisonous to humans and livestock, if ingested in significant quantities. Don’t eat any part of Milkweed plants. Perennial hardy to Zone 3.
Please use the drop down menu below to place your order.
How To Grow
140 to 180 seeds per gram. Naturally stratify seed by sowing directly outdoors in the fall in a sunny site - cover seed very lightly with soil. Indoors sow seed in a soil-less medium in early February, barely cover seed as diffuse light aids germination. Stratify seed by placing container in a refrigerator or other cold place for 3 months. Bring the container out and keep at 20 C (70 F) for the 10-18 day germination period. Grow on under lights at a slightly cooler temperature before hardening off and transplanting outside after the danger of frost has passed. Plants grow 60-120 cm (2-4') tall. Seed from mature plants disperses easily by wind action.
Blooming Season Begins
Start Indoors or Sow Direct in Fall
Days to Emergence
10 to 18
Medium Tall %2860 to 90 cm%29%2824 to 36%22%29
Degree of Difficulty
Native of Canada
Native habitat rejuvenation and regeneration.
Butterfly and wildlife garden essential.
Essential plant for Monarch butterfly survival as a species.
Excellent drought resistance.
Many native plants produce seed that is viable but dormant. This means that while the seed has all the internal structures and nutrients required to germinate, the seed coat is so hard, water cannot pass through it and initiate germination. When seed is in this state, it is known as being dormant. Seed dormancy is a naturally selected for trait that protects the seed of many plants allowing them to safely overwinter and then be ready to sprout in more favourable conditions in spring.
The remedy to naturally breaking seed dormancy is typically the passing of time. In particular, seed overwintering outside and experiencing the natural freeze thaw cycles that occur in late fall, winter and early spring. To artificially break seed dormancy, sow the seed in a soil-less mix, water than chill in a refrigerator for a set period of time. This dormancy breaking process is called stratification.