Bare-root trees should ideally be planted as soon as they arrive, preferably the same day. However you should not attempt to plant them if the ground is frozen. While we supply trees throughout the winter, in some regions planting is only possible in early spring when the ground has thawed - so you may need to store the trees for a period.
If you just need to wait for a few days you can keep the trees in a frost-free shed or garage. Do not uncover the roots, and make sure the tree is not exposed to frost.
If you need to store the trees for longer, you should dig a shallow hole, remove the covering and packing material from the roots, and lie the tree on the ground so that the roots are in the hole. Then cover the roots with soil or sawdust and press firmly - this removes the air and prevents frost damaging the roots. This is known as "heeling-in".
You can also do this in a cold (not heated) garage. Just put a sheet on the ground, remove the covering and packing material from the roots, and lie the tree on the sheet. Then cover the roots with soil or compost.
When you come to plant the trees, if you think the roots look dry, you can stand them in a bucket of cold water for 4-6 hours, which will help to re-hydrate the roots - but only do this immediately before planting.
It is very important that you plant the tree out before spring arrives. Once the tree starts to "leaf out" it is unlikely to transplant successfully.
Warning: Never try to store the trees in a heated room or inside your house. They need to be cold (but not freezing), not warm!