Siberian Crab Apple Cultivars

• The fact that there are many Siberian crab apple cultivars available means you can choose the variety that best suits your needs. For a slightly more exotic-looking tree, plant the weeping Siberian crab apple, known as malus baccata "gracilis." This dense, compact tree features branches that hang down slightly at the tip and produces aromatic white flowers in spring; the fruit, which is set in late summer, is a rich autumnal gold. It it winter-hardy and has good resistance to disease. Plant the columnaris cultivar for a statuesque tree with upright, columnar growth. The fruit is yellow, tinged with red and the cream-colored buds produce pure white blossoms. According to the Backyard Gardener website, this cultivar is not disease-resistant; avoid over-pruning and over-fertilizing, as these can increase susceptibility. For a Siberian crab apple tree with good disease resistance that features maroon fruit in the fall and pink-tinged buds that bloom white in the spring, try the Jackii cultivar.
  
  

Planting Techniques

• The best time to plant your Siberian crab apple tree is in the spring or the fall, if it is sold balled in burlap. If you bought a bare-root tree, plant in spring. For best flowering, select a site with moist, well-drained, acid soil in full sun. To allow the roots to establish themselves, dig a hole that is three times the diameter of the rootball, and at least as deep and loosen soil well. Amend the soil with organic compost if it is nutrient-poor or sandy. Plant the tree with the burlap still encasing the root ball, placing it in the center of the hole so its best side faces forward. Make sure the burlap edges are tucked into the hole and backfill, tamping down lightly. Create a 10-inch berm, or raised ring of soil around the tree, in order to help water reach the perimeter roots; this will encourage outer growth. To conserve moisture and protect the roots, mulch over the water ring 3 inches deep with peat moss or pulverized bark. Water generously.
  
  

Planting Aftercare

• During the growing season, water your Siberian crab apple deeply once a week. Wait until the tree is 2 years old before fertilizing it; the best time is in the spring before it blooms. Use a nitrogen-rich fertilizer, such as a 20-5-10 formulation. Prevent leaf diseases by pruning to eliminate crossed branches and suckers, and to open up the crown. Don't inadvertently remove flower buds; prune in late spring.