A few decades ago (well before the internet age had propelled the sharing of great gardening ideas) many gardeners believed that transplanting native milkweed was impossible.
The species that gardeners have problems transplanting are the varieties that do have these tap roots….tapped out species include Asclepias syriaca (common milkweed), Asclepias tuberosa (butterfly weed), and most other milkweed varieties native to the US and Canada. Some non-native varieties, like G. fruticosus (swan milkweed) also have them.
There are 3 main reasons we transplant milkweed:
- milkweed plants are spaced too close together
- a milkweed variety seems unhappy in its current growing conditions
- experimentation- we have been split-testing milkweed varieties in different microclimates of our yard, to see what growing conditions they prefer
While transplanting native milkweed isn’t rocket science, many have tried and failed because their plants have been unnecessarily stressed.
Try these simple tips, and join the growing numbers of gardeners who are successfully transplanting milkweed in their yards and butterfly gardens.
8 Tips for Successfully Transplanting Milkweed
1. Before transplanting wild milkweed, be sure it’s really milkweed
I have received numerous emails over the past few years from gardeners wondering why their milkweed isn’t attracting monarchs. After seeing photos the problem was clear…they had transplanted wild milkweed that wasn’t milkweed!
Unless you’re transplanting from a place where milkweed gets mowed, please reconsider taking habitat away from the monarchs, that they desperately need! If you can’t find seeds or plants locally, check out the many options you have for buying online:
2. Amend the soil if needed
We typically add compost to areas we are transplanting milkweed. It’s better to do this before planting because you can mix it into the soil easier.
You can find this for a good price at local garden centers or big box stores.
3. Practice First!
Like anything you do in life, you’ll get better after you transplant milkweed a couple times to get a good feel for it. If you have ten plants you’re going to move, start with two to see if you can keep those alive. Then proceed with the rest…
4a. Transplant in early spring
When you see your returning milkweed plants starting to pop their little heads through the soil that is prime time to transplant:
More growth and foliage on the plant will only make transplanting more stressful. Cooler spring temps will also help the plant to acclimate quickly to its new environment.
4b. Transplant in late summer and early fall
If you’ve read other posts on this blog, you’ll know I’m a big fan of fall planting. In Minnesota, we typically fall plant and transplant from mid-September to mid-October. This give the roots plenty of time to get acclimated before the ground freezes.
The milkweed foliage should be about fried when you transplant at the point in the season, and you can cut the plant back to about a foot…leaves a nice marker for where the plant should emerge next season.
Later, you can apply some leaf mulch insurance to protect the roots over winter.
5. Dig deep to get the entire tap root
The more of the root system you get, the likelier your transplant will be successful. I have lopped off a tiny bit of taproot and had plants survive, but the more you can get the better.
Dig around all four sides of the plant before attempting to lift it from the ground. Dig about 4″ out from each side to avoid cutting the taproot.
We use a transplanting spade to get underneath taproots, which has worked well for us.
6. If you don’t get the entire rhizome, transplant the remaining piece horizontally to multiply your plants. Good candidates should be a few inches long with several nodules on it. Community member Mary says this method yields a 95% success rate in her northern California garden.
7. Start Small, Win Big
It’s much easier to get the entire tap root when digging up a first or second year plant. If your milkweed is more mature, you’ll need to dig deeper for success.
8. Keep soil moist after transplant
For the next couple weeks post-transplant, make sure the soil stays sufficiently moist to help the plants acclimate to their new homes and encourage root growth.
With spring transplants, you can start lightly fertilizing after the plant starts putting out new growth.
9. Cut back stalks/foliage to increase survival rate if transplanting mid-season
This is a judgement call, and depends on the size of the plant and weather conditions. if you’re going to cut back, better to do it right away. If you’re transplanting a large plant, which is not advisable mid-season, cutting back is probably a good idea.
If you want to try a midseason transplant without sacrificing stems and foliage, community member Paula B. says she has had success using Superthrive to give plants extra nutrients to help them through the transition. More info and reviews here.
Community member David recommends another transplanting solution that has also received high marks: Quickstart Transplanting Solution info and reviews