Wow - you have enough worm castings to consider tilling them into your garden?? That's impressive! To answer your question regarding whether to compost it -- vermiCOMPOST already IS the ultimate compost!

I get maybe a 5-gallon bucket per year from my wrigglers, so cannot be so extravagant with it. I mix some into potting soil mixtures I make up when re-potting houseplants or potting on vegetable seedlings. Sorry, I don't really measure...say, maybe 2 tablespoons or so to a gallon of mix (usually about 2 parts peat &/or coir to 1 part each vermiculite and perlite). Not scientific, but I seem to get satisfactory results.

In the garden, I add a couple of tablespoons right into the planting holes when I set out my plants, or sprinkle some generously along a furrow and work it in lightly.

Hope this helps.

Thanks for the info. Someone gave me several bags of castimgs. I'm trying to figure out best way to use them all. Plan to make some tea but that doesn't take many castings. Do they go bad still in a dry location in bags?

I allow mine to dry out thoroughly and then store them in buckets or plastic bags. They do not go bad. If you use plastic bags, though, be sure the casting are dry or I am not sure they would not mold, depending on how thoroughly they are composted. And I always sift mine so they are finer than coffee grounds. I put larger bits into a different container for use outdoors or the coarser stuff back into a new bin. There are many ways to accomplish the same end; I am sure others have different techniques. Just like there are many ways of gardening. :-)

My understanding is don't let them dry out completely. Most of the microbes will die off. Some will go dormant and awaken when moistened again, but just a fraction of the starting population. The ratio most often cited is use 20% Vermicompost with 80% soil or potting mix. When transplanting plants I dig out the hole, mix some VC 20/80 and put in the hole with the plant. When planting seeds in rows I sprinkle the trench/mound/holes with vermicompost (estimating 20/80), put in seeds, and cover with soil. Like weedlady said, do not compost vermicompost. It's already as good as it can get. Hot composting vermicompost would kill most of the microbes.

What I have found using vc is that it is very water holding and its best to only use 1/4 of whatever I mix it with.

I had not considered the need/advantage to keeping the microbes viable. Just was thinking I did not want the vc to mold or smell. So I looked into this further and charitycomposter is correct. Here is a good site with Q & A on that topic info: Redworm Composting

I spread it around, as-is: worms, cocoons, bits and pieces of unprocessed stuff. Depending on how I am managing that particular area, I might just dump a front end loader sized portion and rake it out, fill a furrow, or disc it in. Sometimes I'll add a bucket to a lasagna bed, or add a couple gallons to a planting hole. I haven't yet found a bad way to use it.

The research/books I've read on vermicompost amounts say that if you use more than 20-25% vermicompost-to-dirt ratio then you begin to experience the law of diminishing returns. After a point using more vermicompost doesn't benefit the plant as much. 100% VC will cause plants to grow too fast and become spindly.