I have already written about milkweed (click here), but that post was a little more technical. Sometimes I get lost in my own research, and start going in circles. If you can relate to that, then this post is probably for you. I’m going to talk about putting milkweed in your own garden, but it’s going to be more informal. This is just my two cents after doing my own research and growing my own milkweed.
Milkweed FAQs
Where to get milkweed or milkweed seeds? Any garden center, even places like Wal-Mart or Lowe’s, should have them. Depending on the season, it may be better to search for a live plant instead of the seeds. Many varieties of milkweed need to be cold stratified, which if you didn’t know, is a fancy way of saying that the seeds need to go through a winter cycle in order to germinate. More on that later.
Is it safe to buy live plants from a garden center? That is a loaded question, and it does not have a simple answer. The fear is that the plant may have been sprayed with an herbicide or insecticide, which of course is lethal to monarch caterpillars. Some places do spray, and some don’t, and some garden centers don’t spray but their supplier does so they may not even know if the plant has been treated. Also, even if the plant hasn’t been sprayed, it almost certainly has fertilizer in the soil which is also toxic for caterpillars.
And the verdict is? In my mind, the main factor to consider before purchasing a live plant from a garden center is your intent. What are you going to use the plant for? Are you buying milkweed as decoration with the hope of attracting butterflies, or as a food supply for caterpillars that you already have? Are you starting a new garden mid-season and want a live plant because you don’t want to cold stratify, or do you need it because you are raising caterpillars and are running out of food? Perhaps you just started and don’t have a regular source of milkweed, or it’s the end of the season and you’re running out? If you’re purchasing a live plant with the intention of using it immediately for your existing cats, be very careful. It would be better to put out feelers first and see if you can obtain milkweed some other way–perhaps a friend of yours has milkweed they can give you. If you do get it from the garden center, wash your leaves very thoroughly before giving to any caterpillars. Better yet, and if possible, wash it multiple times over the course of several days before using.
When you are adding milkweed to your garden more for decoration, with the hope of attracting monarchs, go ahead and get it from the garden center and don’t worry too much. Give it a good hose-down, including the leaves, preferably a few times, in case it’s been sprayed, and add a layer of potting soil to the surface around the base after you plant it so no fertilizer is exposed where caterpillars may be crawling. Even if monarchs start laying their eggs on it immediately after you plant it, which is doubtful, it takes about a week for the caterpillars to hatch and start eating.
What kind of milkweed is best? There are a million varieties, but I’m not going to talk about that now. If you’re looking for that kind of detail, check out my other milkweed post. Here is how it works in actual practice: some varieties of milkweed are prettier than others, and some are more utilitarian. Some milkweed varieties grow better in different climates, so knowing what is native to your area will help narrow the search. Check out the Milkweed section on my Resources tab to find out what is native in your area. A lot of milkweed varieties need to be cold stratified, which can be a lengthy process (this is why you may choose to purchase an established plant instead of seeds).
If you choose a seed that requires cold stratification, you can mimic that process by putting the seeds in your fridge or freezer for a period of time. The point of the process is not just to make the seed cold, but to make the temperature fluctuate as it would in Spring. I have had luck planting my seeds in potting soil and watering, then putting the whole container in the freezer for a week. I thawed it for a day and refroze it. There are many methods described online… You may need to experiment to find out what works for you.
How many plants are needed? What will they look like? Can milkweed be incorporated with an existing flowerbed? When putting in a butterfly garden with the intent of raising monarchs in captivity, it is recommended to have no less than 10 plants and 2 varieties. If you do not plan to raise monarchs–and you should not feel pressure to do so!–just plant 1 or 2 of whatever you think will look nice with your existing scheme. Some of the milkweed plants do look very pretty and have a relatively small footprint and could easily be added to an existing landscaping plan.
I’m in the Midwest, so Common, Swamp, Butterfly Weed, Poke, and Whorled are native for me. I have planted Common, Swamp, and Butterfly Weed. Aesthetically, I like Butterfly Weed the best. Butterfly Weed is squatty and bushy compared to Swamp and Common milkweeds. It has pretty orange flowers that also attracts the adults. In contrast, Swamp milkweed, which does get pink flowers, is tall and stringy. Common milkweed is somewhere in between, but definitely not as pretty. Evidently it’s supposed to get flowers, but I’ve never seen any. It gets hit with an ugly stick in the fall, too. I have a spot a little more out of sight, so I put my Common there because its leaves are huge and they go a long way when you’re rearing monarchs. Butterfly Weed and Swamp have much thinner leaves and can get eaten down to the nub pretty fast. My Butterfly Weed and Swamp did not spread, and but Common will spread out over time, and if you put it somewhere and then change your mind, it can be challenging to get rid of it.
I also (gasp!) grow Tropical milkweed in my garden. It is not a native plant in the US, and there are a lot of native-planting die-hards that would like to string me up by my toenails for intentionally planting something that doesn’t belong here. The main reason that I do it is because it truly is a magnet for the adult monarchs. It has really pretty red and yellow flowers. In the southern states where OE is more prevalent, Tropical milkweed can exacerbate the spread of the disease if proper precautions are not taken (mainly, cutting it back). However, in the Midwest, Tropical milkweed is an annual, so here there are no concerns about carrying OE from one season to the next. For people that are further south where it does not die off naturally, you can still plant it if you are willing to take on the responsibility of cutting it back in the winter. This will mimic a die-off and keep OE in check.
Bottom line: for an average gardener with no intent of raising monarchs, I’d grab some Butterfly weed and call it a day.
What else does one need to know about milkweed? The white sap inside the milkweed plant (of all varieties) can be very dangerous if not handled properly. There is a scary thing that can happen if you get the milkweed sap in your eyes: click here to read about Corneal Endothelial Toxicity. The most common way for people to get milkweed sap in their eyes is by secondhand inadvertence. I may have made that phrase up. It’s accurate though: usually it happens when someone is handling the cut leaves. If you forget that it got on your fingers and wipe your eyes, or forehead and the sweat makes it run in, or something like that, that’s all it takes. But as long as you are aware and take precaution, there is nothing to worry about. I have a rule with my kids that they aren’t allowed to touch the milkweed, but that’s only because they are terrible about picking flowers and weeds and making bouquets, and I know they would not remember to wash their hands. The sap doesn’t squirt out randomly, and it washes off with plain soap and water. If you’re handling the leaves, cutting them off to feed caterpillars or what-have-you, it is not a bad idea to wear gloves and even safety glasses, but suiting up in haz-mat gear really isn’t necessary. This isn’t my quote, but it’s sound advice: “Milkweed is like Coronavirus. Wash your hands frequently and don’t touch your face.”
Is milkweed enough to get monarchs? No!! Milkweed is the food for the caterpillars. But to get caterpillars, first you need to attract the adults. Make sure you have plenty of nectar flowers nearby. Planting whatever is native in your area is always a good idea because native plants are the easiest to care for and will have the least amount of pest issues (which is not to say they will not have pests, but native plants keep the balance–if they get pests, they’ll also get the proper predators to eat them). But if there is something non-native that you really like, I say go for it! Every little bit helps, and nectar is nectar. So if it’s between planting something non-native, or not planting at all, then to me the answer is clear. Do a little research to make sure that if it’s invasive you can take measures to keep it under control. Most websites that have details about plants will also include the pests it may attract, so look into that as well.
My recommendation? Remember, I’m in the Midwest, so this may not work for you. I’ve had really good luck with Zinnias, Black-eyed Susans, Coneflower, and Dianthus. I just planted Mexican Sunflowers this year; not sure how popular they’re going to be yet.
Simply Sunlight 