Milkweed, Swamp 

Asclepias incarnata

This is a perennial that is native to most of the continental US and parts of Canada.  It is an excellent food source for not only Monarch catapillars, but other butterflies such as Swallowtails. Easy to start from seed, it grows to about 4' tall and spreads to 2-3' wide.  This is a wonderful nectar source for all manner of pollinators late in the season, especially after many other wildflowers have faded.  You will be dazzled with the visitors that you get with these growing in your garden!

Packet: (0.5g~95 seeds) 

Bulk: 2.5 g.

* Growing Tip: Being an undomesticated plant, milkweed benefits from a period of cold stratification to help the seeds "wake up".  To do this, one method is to plant in the fall, as would happen in nature.

Or...you can place the seeds on a moist paper towel and put them in a plastic bag in the refrigerator for about 30 days.  Check it periodically to see if mold is forming, in which case change the paper towel.  This will greatly improve germination.