Why Is My Mint Doing Worse In Better Soil?

Question

Hi there-so we have mint growing wild in our backyard–in clay soil, downslope from a pool-so it is getting constant ‘drinks’ of chlorinated water. I don’t care–I’m actually trying to kill it off. Partial hot sun in the summers, and it thrives. But also, once autumn hits and it gets to about 40-50 degrees F, still thrives. Really only snow kills it. Horrible growing conditions. Yet it THRIVES!! I get it–mint is voracious. But I uprooted some and planted it in pots (for culinary use, without it taking over my yard) with VERY good soil-great drainage, great nutrients, EXPENSIVE stuff- every other plant I have LOVES this expensive soil. I water the potted mint almost daily and the soil stays moist, not soggy or waterlogged. Yet the potted stuff doesn’t thrive as much. It doesn’t die or anything, but it just won’t go CRAZY like the stuff in the clay soil. I get smaller leaves–darker green than the bright green plants growing in the yard, and they aren’t as ‘tender’ as the wild plants. Also the potted plants just grow ‘out’ (creeping) while the wild plants will grow ‘up’-almost to the size of small bushes! Should I maybe ammend the soil in those pots to have more clay? I’m just stumped. Thank you!

Answer 1

First try watering less and giving it full sun. Also, make sure the container is not too large for the plants. The container width should not be more than two inches larger than the root ball. If the container is too large, it holds excessive water, which can lead to root rot.

You don't say if it is a cultivated variety or truly a wild form. But even a wild form prefers rich, well drained soil. I suspect the one in your yard is getting less water, less or no additional nutrients, and more sun. You could repot it in all purpose potting soil if more sun and less water doesn't help. Also cut back on the fertilizer. Try to duplicate the conditions in the yard.

Also, check for aphids or spider mites.

Here is more:

https://www.gardeningknowhow.com/edible/herbs/mint/how-to-grow-mint-plants-in-your-garden.htm

https://www.misin.msu.edu/facts/detail/?project=misin&id=261&cname=Wild%20mint