How to grow herbs that are invasive
Hello, I wanted to plant mugwort this spring but I've been reading that they multiply quickly and become invasive and seem to "take over." I've never grown it before so I want to make sure I'm taking the right measures since I have a garden with other crops (lettuce, basil, other greens) that I don't want to be compromised by the mugwort. How do you grow something that can become invasive. Should I grow it in a container instead? And how big does the container need to be? Would this also be the same case for mint that kind of grows crazy too? Thanks.
You have a bit of a dilemma. The accepted way to grow mint (and by extension mugwort) in order to control it, is to grow it in a container. However, that is not really foolproof enough if you set the container on the ground or into the ground. The roots will grow out of the drainage holes in the bottom. The roots can be very fine and, because of their aggressiveness, are the biggest problem. The plants could also root from stems that flop over from the pot and root at the point where the stems touch soil, and it will keep going unchecked.
The only way we would recommend growing these plants would be to place them in a container on a deck or other impermeable surface. Also, don't let them seed. Since mugwort gets a fungal disease in the summer that makes it an unsatisfactory groundcover, it is grown less and less.