Germinating Milkweed Seeds at Home
One of the delights of the summer and fall seasons is the flight of the monarch butterfly. These beautiful insects have evolved with the plants of the milkweed family (Asclepias) that provide the foundation for their larvae (caterpillars) as well as nectar for the adults. The sap of the milkweed plant contains an alkaloid that is non-toxic to the monarch, but the caterpillars eating this plant are distasteful to most predators. Birds leave them alone. The startling drop in number of migrating monarch butterflies over the last several decades is partially attributed to the lack of available milkweed plants. Modern farming practices discourage milkweed propagation and it has only recently become a plant that gardeners include in their gardens. Starting a milkweed patch requires some patience but the rewards are great. Not only are you helping out the dwindling population of monarch butterflies, but the beauty of the plant is something wonderful to behold.
The most economical method to begin a milkweed patch is to grow them from seed. Collecting seed in the fall from the pods is easy; separating the fluff (coma) from the brown seeds can be problematic because this floss will blow around so don’t do this procedure inside the house! This fluff or floss helps nature disperse the seeds in the fall winds. By propagating seeds at home we are roughly duplicating nature. These seeds disperse in the fall, lie fallow all winter on the soil surface, and germinate in the spring after all freezes and frosts. We can fool Mother Nature if you follow these steps.
Place the seeds on a wet paper towel, place the towel in a zip lock plastic bag that is clearly marked, and putit in the refrigerator. This is called stratification and is a requirement for success. Be sure to mark the bag with species, date put into the fridge, and another date about 30 to 60 days later. This later date is the time when you are ready to begin the active germination process.
Remove the seeds from the bag and inspect. Some seeds will be plump; others will show no change. It is the plump seeds that you will want to work with. Remember, there should be a minimum of 30 days cold stratification.
Prepare your propagation area by gathering together some peat pots or plastic starter trays with inserts, a sterile potting medium (mix of peat, perlite, vermiculite, commercially available) stratified seeds (see above) and a warm sunny window sill or a commercial propagation heating mat.
Fill the pots with the sterile potting medium that has been dampened. Place seeds on the surface and gently press them into the soil. I suggest that in a seed-starting kit that at least two seeds be placed into each cell. If using peat pots (highly recommended) I’d press in about a half dozen. Cover the seeds lightly with potting medium (or coarse perlite if available), mist with distilled water (use water from your dehumidifier) and cover with a domed lid from the seed starter kit, or use clear plastic wrap. Keep the tray or pots in a warm place at least 70 degrees for 7 to 14 days. A good warm spot to begin this process is the top of your electric hot-water heater. Germination should begin. NOTE: If you are germinating Butterfly Weed (Asclpias tuberosa seeds, these seeds require a period of strong sunlight to begin the germination process. Put tray in a warm sunny window sill until the first true leaves show in about one month or so. Be sure to keep your seeds moist but not soggy; watering from the bottom by pouring the distilled water into the tray is a good way to keep the potting medium moist.
After a few months of careful tending, the plants are ready for the garden. Remember, these seedlings have a long taproot and don’t like to be disturbed. That’s why I like using peat pots because the whole pot can go into the ground without disturbing the roots. If there are several plants in a cell or pot don’t despair. They will take hold and grow for you. The monarch butterflies will thank you!