The Siberian crab apple tree ((Malus baccata), also called a Siberian crab tree, is a highly adaptable and cold-hardy tree that is grown for both ornamental purposes and for its fruit production. The flowers of Siberian crab apples tree are showy, white and fragrant. The fruit of Siberian crab apple tree are used to make sauces, desserts and jelly. Siberian crab trees can grow to approximately 25 to 30 feet tall and are hardy in USDA zones 2 through 7. Plant a Siberian crab in full sun and make sure it's provided moist, well-draining soil.
Set the bare-root Siberian crab apple tree into a bucket of water to help plump up the roots in case they have dried out. Leave the Siberian crab tree soaking in the bucket of water for no more than 24 hours.
Dig a planting hole for the bare-root Siberian crab tree that is twice the diameter of its root system and approximately the same depth. If in doubt, dig a planting hole that is 2 feet wide by 2 feet deep.
Mix into the soil that was removed from the planting hole an equal amount of an organic matter. You can use compost, aged manure, leaf humus or peat moss. Create a conical mound of soil in the planting hole that is approximately half the depth of the planting hole.
Remove the bare-root Siberian crab apple tree from the bucket of water. Place the tree into the previously dug planting hole. Spread out its roots over the conical mound of soil.
Hold the Siberian crab tree level in the planting hole. At the base of the trunk, locate the graft union, or graft bud. This is usually marked by a slight nodule and discoloration. The graft union needs to be planted 1 inch above the level of the surrounding garden soil.
Remove the Siberian crab apple tree from its planting hole, if necessary, and either remove soil, or scoop in more soil until you are sure the tree is set at the correct level in the planting hole. Scoop the organic matter and garden soil mixture into the planting hole to fill it half full. Pour water into the planting hole until it's about 3/4 full and let it drain away fully before proceeding.
Scoop in more soil to entirely fill the hole with soil. To help with watering, create a 6- to 8-inch high dam of dirt approximately 18 to 24 inches in diameter around the Siberian crab apple tree. Then, spread a 2-inch layer of mulch around the Siberian crab. Use grass clippings, bark or any other mulchlike material.