I live in Toronto. I’ve been reading online and watching some videos that recommend that we plant mint in a pot and then put the pot in the ground to stop the mint from spreading. I like the idea but would like to know:
1. If the mint will come back each year if I do that.
2. If I cut the bottom of the pot off for better drainage, is the mint able to spread that way?
Planting mint in a pot is an excellent way of controlling its tendency to spread throughout the garden. Mint is a perennial and should come back each year, although the plants die back over winter.
The pot’s rim should be just above ground level, so that the roots are not able to grow beyond the edge of the pot, as this is a way the plant could spread. The pot you use should at least have a drainage hole, although often “bottomless” pots are used. Mint’s roots are quite shallow, so should not escape from under the pot, as long as the pot is at least 12.5 cm (5 inches) deep. Make sure the pot is intact, not cracked – or the roots will find a way into the surrounding soil and the plant will spread.
The mint will likely become root-bound after about 3 years, and you will see the centre of the plant die. When this happens, remove the mint from the pot, cut its root mass into 3 or 4 sections and replant each in a new pot, with new soil.
There are many websites that provide details on “how to” plant containers in the ground. For example, SF Gate’s How to plant containers sunken into the ground may be of interest to you.
Enjoy your mint!