I'm no expert here. But in the short term they aren't bad, they just don't help much in a container. In the longer-term I've seen worms completely burrow, push, and/or consume out all the soil/media from sections of container trees. The roots then become dried/crispy.

In the earth where the ground is very compacted the burrowing action is extremely helpful to create macropores for aeration and water flow and their byproduct is beneficial when other microbial life helps break it down. In a container, the soil should already be (relatively) aerated and without compaction and the other life forms aren't established to consistently help. Therefore, you don't want to further reduce your already limited space for the roots without the added benefits the worms normally provide.

If you search for a worm slurry, I think this forum has several recipes for gracefully removing them from a containerized plant. I think mustard is commonly used, not sure.

I tend to look at media structure (more specifically the o/a porosity and air porosity at container capacity) and media longevity as the properties we should most judiciously protect, because w/o adequate porosity and a stable medium, it is a certainty we will forfeit some degree of ability for the plant to grow to its potential. Since earthworms in containers impact both media structure and longevity in a negative way, I feel I'm to the better w/o them. Of course, if your goal is simply speeding up the break down of materials you've tossed into a container via the addition of worms - have at it. In that capacity they are indeed effective, though not necessarily to the betterment of any plants growing in the mix.

Al

It sounds to me as if your containers are very small. If your compost is finished, there's not much left for them to eat. I can't imagine that the worms would live very long in such an environment. When they die, they'll biodegrade quickly. Digging up your plants to remove them could cause more harm than just leaving them there.

My containers are on the ground and most, over time, will accumulate earth worms. I only find them when repotting or making divisions. They stay in the old mix. I don't find them to have done any harm, nor do I think they will be a benefit in the new mix. Al

Ok guys, thanks! What I'll do is leave these as-is but in the future I'll sieve the soil to look for them before making a planter set. Also seems a good idea for me to read up on what all common soil worms eat and what they leave behind and possibly (though unlikely) to ID these.

Thanks for the input!

Common soil worms eat the things that eat the decaying plant matter.

Josh

Calistoga/Al: Did you find worms doing repots or potups?

I'll catch a few here and there (however, not in the gritty mix) when potting up and the mix will look just fine. But it's when I happened to bare-root that I saw the true "damage" I pointed out above. The worst I've seen were always from big-box store purchases. I can only assume they have been there for quite some time to do that much "re-arranging" of the media.

Joraine: The worm evacuation slurry I recall was not harmful to the plants nor the worms, in case you're interested.

I have a potted plant growing area on an asphalt surface covered with landscape fabric. I have between 200 and 300 one gallon pots at any one time. The potting mix I use for these is a commercial mix I buy by the yard. It is construction sand, fir bark and volcanic rock. Pots with the gritty mix are kept in a covered area. I have never found worms in the gritty mix. Plants not sold are divided and repotted for the following season, they are seldom potted up to a larger size. How the worms find their way into pots on an asphalt surface is a mystery to me. Al

re calistoga: interesting timing for that comment, I've always idly been curious about worms behavior during rain and for the first time in my life, saw them climbing walls during a heavy downpour. It had been raining on/off for a couple days and thats when I collect them because theyre ontop of the ground.

Imagine my surprise when I notice several squirming their way up a vertical 5 foot wall next to my door. I looked around and realized there were quite a few on the walls all over the complex. 40 Yrs old and this is the first I've seen that

Very cool observation about the climbing worms. I've seen them climb a few inches, but never that much. I have to admit I really like earth worms, and I like how efficiently they turn garden debris into garden gold. In the summer I keep many of my house plants on a patio of Spanish tile. There is a Chinese elm tree that drops a lot of leaves and twigs on the patio. If I don't get out there and sweep up the debris at least once a week, it will be full of worms and beginning to be composted. I just dump it in the compost pile where hundreds of worms are at work.

When I water my plants it's not in uncommon to see worms come to the surface to avoid being drowned. They've travelled through the potting soil from the drainage hole to the top, which reassures me that the soil isn't compacted.

I am surprised to hear about the "damage" they apparently did in the plants from the big box store. Perhaps that was done by something else. I don't trust those big box stores to do anything right about plants.