Controlling Common Milkweed



I am running into a bit of an issue with the more prolific native plants in my garden and my neighbour and was wondering if maybe you or anyone of your members has run into this problem before and have any ideas on how to best mediate.

A few years ago we were lucky enough to have some common milkweed (Asclepias syriaca) self seed in our perennial lawn. We are fans of a controlled ‘wild’ look and were happy to include some pollinators in our lawn. Unfortunately our neighbour is not a fan, and the taproots have been spreading into her side of our shared median bed.

Everything I’ve read about the milkweed suggests that it’s unfortunately difficult to transplant without harming the plant. I’ve offered to come in and remove the offshoots and roots from her lawn (either by digging or clipping), but she declined.

I’m wondering if you have any advice in cases like this?

Thank you in advance!


Thank you for contacting the Toronto Master Gardens with you inquiry.

It is unfortunate that not everyone appreciates the beauty of native plants and their importance in attracting pollinators to the garden.

While common milkweed has developed a reputation for being a pest, milkweed is also an integral part of the life cycle of monarch butterflies.  Common milkweed spreads through seed dispersal, but also through underground rhizomes. When the rhizomes are severed during hoeing, a new plant forms from each segment. To reduce the risk of severing rhizomes, hand pull the entire plant, including the roots. Pull out as much of the rhizome as possible. The best time to pull plants is when they are young and before the roots are deeply established.

Another way to kill common milkweed is to mow it every two to three weeks before the seedpods form. Mowing weakens the plant and eventually the plant dies. If the milkweed plants have seed pods before the first mowing, cut the plants near the bases, using pruning shears, and collect the debris to dispose of with the rest of your yard waste. Make sure no seed pods fall on the ground where they can sprout new plants. After pruning the plants, mow every three weeks until the plants die.

You can also try putting a metal/plastic barrier down the middle to prevent the roots from penetrating through to your neighbour’s side.

Good Luck!