How to evict mint when it refuses to leave
Q
Several years ago, I purchased a small container of “living mint” at my local grocery. When I finished using it in a recipe, I planted the remaining 1/2 package in my yard. Recently, I had fresh soil delivered for the plant beds. Well, fast forward to the present day and my flower bed has been overrun with mint! It is now knee-high. Apparently, the mint loved the new soil, not to mention all the moisture from recent rains. What can I do to control the growth?
A
To the ancient Greeks, mint signified hospitality. Somehow, I think you know why — once it's planted you can never get rid of it.
Mint (and many of its relatives) are notoriously invasive. We've planted it in large pots, but it requires constant vigilance because it keeps trying to escape. It easily roots along its stem, so as it grows and sprawls, it will set roots into any soil it touches. The soil doesn't have to be very good, either. We had a catnip plant (another mint family member) that seeded itself on our brick pathway. By the next spring, there were teeny tiny catnip leaves growing out of the sand between the pavers.
Getting rid of it will be tedious but not difficult. First, pull up as much as you can. The roots are not going to be very deep, thank goodness. Whenever you see it coming back, immediately pull it out. Do not let it flower! Eventually, you'll exhaust it and it will go away.
If you want a more immediate result, use a broadleaf herbicide (such as
Roundup) when the mint reemerges after your initial weeding.
Whatever you do, don't compost it!
Q
Other than mint, what other plants can become
invasive?
A
Mint is the most notoriously invasive herb, but there are other herbs and ornamentals that I would steer away from.
▪ Epazote is an herb that, when added to bean dishes, supposedly prevents flatulence. It also produces thousands of tiny seeds that spread everywhere. Just use Beano instead.
▪ Amaranth is a beautiful, red-leafed herb that produces large seed heads. The leaves can be used as cooking greens (they taste like spinach), and the seeds are used as a grain. We planted it in our garden 10 years ago, and we are still pulling out random plants today.
▪ Mexican evening primrose is a beautiful, pinkflowering ground cover that is still sold in garden centers and nurseries, but it is also extremely invasive.
▪ Morning glory vines bear jewel-colored flowers, but those flowers will drop seeds everywhere. The seed packets instruct you to scarify the seeds and soak them before planting. Oddly enough, all the seeds that fall from the plant don't need any special treatment before germinating and taking over.
These are only a few of the many invasive plants we've had firsthand experience with. The official list of invasive plants is quite long and growing every year. See cal-ipc.org/plants/inventory for more information.