The term compost means something different in the United States than it does in Britain, and the OP may have been using it in a different way than is commonly understood on this forum. The British and Europeans often use the noun "compost" to mean potting mix. A common potting mix in Britain is called John Innes compost. The NPK is supplied by a combination of organic amendments. Here's a description. John Innes Composts are a blend of carefully selected loam or topsoil, sphagnum moss peat, coarse sand or grit and fertilisers. The loam is screened and sterilised and then thoroughly mixed with the other ingredients in proportions designed to achieve the optimum air and water-holding capacity and nutrient content for different types and sizes of plants. Sorry to say that when I started out growing container plants back in the day, I got all my advice from Thalassa Cruso, who was the Julia Child of gardeners in a popular public television series and published several books on the subject. Everyone made their own mixes in her day. Here is a link that might be useful: John Innes Compost recipes

Can you get a picture of them? I reuse container soil too. I've noticed things in there before but only worried about them when they ate my plants.

I'm in the same 'boat' as you are. We have sand, sand and more sand. Heck...we couldn't even grow grass until we had topsoil brought in...ughh!!! Assuming that your container soil is basically peat with some perlite and vermiculite, why not try layering that in the area that you will growing in next year with some newspapers, manure, leaves, compost...anything that will breakdown over the winter. In the gardening book, "Lasagna Gardening", this is precisely what the author does. She 'creates' good soil, by adding organics and then letting the whole pile just decompose. Come Spring, she just pokes holes in the now compacted pile and puts in the plants or seeds. As far as the bugs go, unless you have brutal winters that can kill them, they'll probably just overwinter and reappear next year. Sorry... I'm not an expert by any means, but your post reminded me of why I choose container gardening over in-ground gardening. Well...that and the fact that my entire property is on a slope ;-) I hope others will be along to help you. Donna H.

Blight is probably what is making people recommend not to reuse the potting mix. The spores that cause tomato blight (the late blight that crawls up from the bottom and makes the leaves turn brown and fall off) live in the soil and are spread to the leaves when rainwater splashes soil onto the bottom leaves. I have reused potting mix for tomatoes by mixing in some fresh compost and using it in the bottom half of the large pot. Then finish with fresh potting mix on top. My theory is the plant is less likely to get those spores if the reused soil is covered. My tomatoes always seem to get blight no matter what, but it was certainly no worse than usual. Compaction is a real problem so if you try this, use very coarse compost or some shredded wood like you would find in coarse potting mixes. Any leftover mix from last year ends up in my compost pile to (hopefully) re-equalize the spore population. I also mulch around tomatoes as soon as they are planted to reduce the soil splashing.