You do not want to fill containers with compost. After just a single growing season, it will have broken down to the point where you have lost any ability for fast drainage (absolutely essential with container culture) and proper aeration and will have only a dense, slodgy mess. Your plants will inevitably suffer.

I'd suggest you visit the Container Gardening forum and look at this thread in particular - it is long and slightly technical but it will explain very clearly the rather unique requirements of a proper container soil.....which really isn't a 'soil' at all. Any nutrient issues in a container are addressed by proper fertilization, not by ingredient. Save your compost for inground or mulch applications where it can be of proper benefit. It has no place in a container!

Well, I've been doing this with fewer containers for several years and have done great. I was just asking about where to store my "compost".......on the ground until spring, or fill the containers now. As far as drainage, I have too much and have had to plug up some of the holes. I'm using poly food-grade stock tanks.

Thanks for that link....I'll check it out.

Because this method has "worked" for you previously does not necessarily mean it is a recommended method or one that has the best interest of the plants at heart. Growing plants in containers is completely different from growing plants inground and different criteria is involved, foremost the medium used. This is even more critical if you intend these to be long term container plantings. You need a very durable (non-decomposing) base and a high textural quality - compost does not offer these attributes.

You are of course welcome to do as you wish, but for the best success with growing anything in containers, leave the compost to inground planting situations.

FWIW, I grow extensively in containers - some very large - and many are permanent, long term plantings.....trees, shrubs and perennials. I also grow seasonal or annual plants and veggies and fruit and use a similar highly textural, durable container mix for them all - no compost.

btw, you can't have "too much" drainage in a container situation :-)

Thanks gardengal.

Since the original question (how to keep nutrients in compost over the winter) is a good one in general, I will offer my opinion aside from the above comments on the use of compost in containers.

Compost is a living thing, it continues to decompose, and it can leach. Based on these facts if compost is to be stored: 1) it is best kept moist (not too dry or wet) so the microbes are happy; 2) under loose cover so it doesn't get saturated with rain or suffocate from lack of air; and 3) use it as soon as reasonably practical.

Thanks for that info, toxcrusadr! That's what I was looking for. :)

If your containers are open to the ground on the bottom, as in a raised bed, then go ahead and use a soil based compost mix.

Really large containers are not easily replenished with fresh potting mix, which will be necessary to maintain that perfect drainage, so take that into consideration.

Thanks chadinlg.

These have bottoms and will be up off the ground on blocks. They are very easy to add more compost/soil to. I don't buy any kind of potting mix, but rather use composted things from our large property, plus plain soil.

My question was more about holding the mix I already have, over winter......whether it would be better to fill my stock tank containers in the Fall, or just leave it all in a pile on the ground.