Hi everyone,
All my fig trees are in containers and I recently have mulched them due to the hot spell last month with coco chips. They seem to be doing much better but when I was checking on my soil moisture, I noticed under the chips and in the soils of one of my plants were lots of tiny millipede like insects crawling in and on the surface of the soil. On another sort of related note, I also had a blackberry bush in a pot that was starting to fruit but had not grown much in the past year. I decided to give up on it and when I pulled it out of the pot, there were barely any roots, and a nasty white cauliflower like chunk attached to it (is this mold?) and lots and lots of white 1 1/2" white and red worms dangling from the roots as well as in the soil. I know they are not fungus gnats-definitely worms of some sort, and also the same little millipedes crawling around the soil. Since I saw the millipedes in the soil of my fig tree too, I can't help but wonder if there are those white and red worms in the fig container as well. If so, do you think they are eating and decomposing the roots? Or are the roots rotting and the worms helping? Should I replant my fig tree in new soil? If so, would I need to wash the soil out of all the roots?
I also received a new fig tree from an online nursery and it is very healthy-in a 14" cone. I haven't potted it but when I slid it out of its cone, there were lots and LOTS of red worms, and grubs poking in and out of the soil. This wouldn't concern me if I were planting into the ground so much but is it ok for potted plants?
All thoughts opinions and advice is greatly appreciated!

The red worms will help aerate the soil and that's a good thing but the grubs, I'm not an expert with grubs but most that live in the soil will eat the roots. Hopefully an expert can chime in.

I generally consider worms in soil or pots a very good thing.  They will aerate the soil as well as help decompose uncomposted items and their castings have beneficial properties.  Most of the other insects, including millipedes, generally are good or neutral as they mostly feed on dead vegetation. 

Fungus gnats can feed on living roots and introduce infective fungus to living tissue, thereby possibly compromising a young cutting.  However, I had a severe fungus gnat infestation in my cuttings a couple years ago, which likely did kill some/many.  But many survived, and once they were in one gallon pots and placed outside, the problem went away.  So I doubt they could do much to a live, healthy tree grown outside. 

Some grubs feed on living roots.  But again, I doubt this would significantly damage a healthy tree.  Just another form of root pruning.  Unless there are dozens of them in one pot. 

Even if you were to do your best to rinse all the soil out of the roots and put in fresh, sterile soil, there could still be eggs of these things attached to the roots that would hatch once you put in the new soil. Even if not, eventually they would find their way into the pot if they are living in the ground, no matter how hard you try to keep them out. 

For the blueberry, maybe the pH of the mix is too high.  They like very acidic soil.

For the figs, if you are in SoCal, growing in the ground would be preferable, but perhaps you are not able to do so.  It's likely that they need a bigger pot, or perhaps there is some other issue with the growing media.  But it's very unlikely that it's caused by the creepy crawlies. 

Earthworms in soil great...earthworms in pots bad......    In the garden the worms have as much space as they want and their tunnels are spread out.  In a pot a couple worms can turn in to a few and the amount of tunnels and air they introduce to the roots and the disruption of the fine hairs on the roots makes for unhappy plants IMHO.  

simple formula to remember;
   kill all grubs
   keep all worms

You really cannot have too many worms. They aerate the soil. They help break down nutrients, and the produce "worm castings" which are considered to be the best organic fertilizer known to man.

Thanks everyone for your input! I know worms are beneficial in gardens but as WillsC noted, I worry about them multiplying- and then eventually turning my roots into a rich vermicompost since they have nowhere to go. Ill leave them be for now and just keep an eye on them.
Rob, I like the idea of natural root pruning- only as long as they follow the 1/3 rule...

The white colliflower chunks on your blackberry roots are rootknot nematodes and they are a bad thing! Do not introduce that to your inground soil. The plant will likely never recover so I would trash the pot, plant and soil it came in ASAP.

Correction needed here. I got to researching my last post as I got to thinking about my post afterwards. Crown Gall is whats your seeing on your blackberry roots. Its just a detremintal to your plant as RKN. Either way it needs to be removed from your yard. When I was growing blackberries the last few years I would notice Crown Gall on canes I cut next to the soil. Although it never spread to the roots the canes would get it at a cut point close to the soil. Sorry to scare you about the RKN but Crown Gall is bad as well, expecially if its in the soil around around other plants.

Thanks blueboy1977 and drphil69, what an eye opener! I just googled crown gall and I am pretty sure that was what by blackberry bush had. I've never heard of such a thing before- I threw away my blackberry bush as well as the pot it was in but I will be so devastated if it effects any of my other trees.. I only heard of RKN being detrimental to fig trees so have always checked for the knots but never heard of crown galls before.. Thanks again. I will have to be extra careful with all my pruning and gardening supplies as well as watering..

No problem! RKN will effect blackberries too. I had 2 plants from the nursery that were infected and had to trash.