Prepare a planting area for your semi-dwarf Gravenstein apple tree in spring. Choose an area that receives full sun, and leave at least 10 feet of space between the planting area and any other trees or buildings. Make your planting hole twice the size of the tree’s root system and transfer the soil to a wheelbarrow. Combine approximately 1 part of organic compost for every 4 parts of soil.
Free the tree’s roots from its packing martial if it is a bare-root tree. Gently shake the sawdust or peat moss off and then soak the roots in water for five to 10 minutes. Also, prune off all broken or rotted roots. If your tree is in a nursery pot, remove it from its pot and gently loosen the roots.
Fill your planting hole about half full with the soil and compost mixture and then set your tree into the hole, distributing the roots evenly around the trunk. Fill the hole to the top with the soil and compost mixture. Be careful not to bury the grafted region of the trunk, which normally occurs 3 to 6 inches above the base.
Water your semi-dwarf Gravenstein apple tree with a sprinkler for about 20 minutes to thoroughly moisten the soil.
Mulch your young tree with compost, wood chips or sawdust to maintain soil moisture and keep weeds away. Leave about 2 inches of space between the tree’s trunk and the mulch to prevent any rotting.
Protect your young tree by covering it with a large cardboard box if the weather becomes unseasonably hot and sunny soon after you plant it; by mid summer, the tree should be accustomed to increasing amounts of sun.