A friend of mine is growing several plants in containers.
A couple of months ago he noticed some worms in some of his containers. He can't recall any obvious reason why that happened. But he really dislikes the worms. He says the worst situation is for his container lemon tree, but others are affected as well.
(I personally wouldn't be bothered by worms, but he really does not like them.)
Is there any way for him to get rid of worms, and not harm his plants?
If the plants are outdoors some of the year or all of the year, then earthworms are inevitable, and are not undesirable. If these are plants he wants to keep indoors, then I suggest he decants them, washes off all the soil, and repots into fresh potting soil - and keeps them indoors all the time.
There used to be products to clear worms from lawns, though these were withdrawn in Europe some years ago. I know of none that can be used to kill worms in pots - and anyway, it goes very much against the grain to kill earthworms, whether they're in pots or in the ground. Sports turf keepers (golf courses particularly) topdress frequently with a sharp and gritty mix to discourage earthworms on the greens, but even that is not intended to kill them.
l have to assume these plants are on the out of doors deck or patio. With constant water and shelter from enemies pots are beloved by earthworms. Earthworms are in all ways beneficial to soil and not once have I ever seen a problem caused by earthworms. Not once and I have lived in the cultivated world for 5 decades.
I would up pot with fresh potting soil in the fall before winter sets in to bring the plants indoors (do you acclimate them before bringing them in or taking them out of doors)?
When you take them back out of doors for the summer, elevate the bottoms of the pots off of the deck or patio using rock or tile pieces. Turn containers upside down and use for a prop or table to elevate the pot off of the surface. Make groups of pots with different elevations. Earthworms will not be a problem.
Nor will rotting deck material from the constant moisture.
Earthworms are very cool but not indoors, please! If the pots are elevated when out of doors with enough ventilation to dry the water beneath the pot after watering, earthworms will not be crawling up to find condo property that doesn't fit their needs for constant moisture. When they have babies there are a lot of worms, a lot. All we need to do is discourage earthworms from buying property in your pots. It is also a good practice to discourage over watering and fungus.
