To heel them in, choose a sheltered, shady site and dig a V-shaped trench. Make the trench wide and deep enough to accommodate the plants' roots and long enough to prevent crowding. Place the plants in the trench at an angle, making sure the roots are below ground level. Refill the trench with soil (don't pack it down) and water the plants thoroughly. Check the soil moisture occasionally and water as needed. "You can leave plants heeled in for months, but I would suggest holding them that way only for a few weeks," says Amy Grotta, extension faculty in forestry education at Washington State University. "You don't want them to break dormancy before planting." Plants that come out of dormancy early are susceptible to frost damage, so plant as soon as possible to prevent harming your new purchases.
When you're ready to plant, carefully remove the soil from the trench and take out the bareroot plants. Soak their roots for five to 10 minutes in a bucket of water. "Don't leave the roots soaking in water for more than an hour or so, because roots need oxygen just like leaves do, and when they're soaking in water no oxygen is available," says Grotta. After hydrating the roots, you're ready to put your bareroot plants in your garden.