Sunday, August 30, 2009
Three Great Reasons to Grow Milkweed
Reason One: it's the host plant to the Monarch Butterfly. There's no better plant I know of to get the Monarchs into your yard. The males arrive and hover around waiting for females to show up. In the mean time they'll help themselves to your other plantings sipping at nectar as needed. Liatris ligulistylis is a good late flowering nectar source for this, if you're more interested in an annual then I'd go with Zinnias. The females eventually arrive and immediately mate if they haven't done so already and lay eggs on the milkweed. It's best to have at least 3 healthy plants (of flowering age) I find. In time they too will begin feeding on what's available. If you don't have anything flowering at the time though then off they go.
Reason Two: Showy seed heads. From their interesting flowers come showy lime green seed pods. They eventually open and reveal their downy covered seeds. When a breeze blows the seeds usually take off. I remember in my youth seeing these puffs of white hair hovering over the yard and assuming they were the result of rabbits shedding.
Some gardeners though might not like these. Unfortunately Milkweed does a good job of reseeding itself. And all it takes is a single rain storm for all the seeds to fall straight to the ground. I have about 100 extra plants that came up this year that will have to be weeded out next year. I think I'll pot a few up.
This wasn't exactly a problem though. Monarch females aren't picky about what milkweeds they lay eggs on. Although they're attracted to the larger plants they still lay an egg or two on the smaller ones. Caterpillars on small plants will strip it of all it's leaves but then move on to other plants nearby.
The other issue about seed pods though is they attract seed beetles. They can be quite a pest too! The beetles will climb over one another and overlap inside the seed pod to resemble the seeds themselves. Adults fly from plant to plant to mate, instead of using pheromones. They only eat the seeds and don't harm the plant but sometimes single plants can get bobbed down with to many beetles. If they become a problem though I'd recommend just removing the seed pods.
Something I've never noticed before is the toughs of brown fur on the thorax.
Reason Three: Monarch Caterpillars! These start out as a tiny little worm no bigger than the egg it hatched out from. As the days go by they nibble small holes in the leaves. Eventually they reach a more noticeable size. Before this time they're completely edible to any predator. After the second or third instar (stage of larval growth) they become poisonous. Though they're still getting picked off by predators they soon stop as they learn how bitter tasting the caterpillars are.
Once they're at the last two instars they proudly consume whole leaves on a daily basis. In time they'll spin a cocoon that's the exact same color as the Milkweed plant and dam near imposable to spot! But almost 2 weeks to the hour it was spun a Monarch Butterfly will emerge. They dry their wings for an hour or two then start fluttering around. Though not in the habit of feeding yet they may even go for some nectar. I've never had it happen myself but I want to say this is when Goldenrod is a better food source for them. Their migration soon starts and they fly away.