Magnolia trees are beloved for their distinctive glossy leaves and large, dramatic flowers that bloom in the spring. Magnolia is a large family of woody trees and shrubs; according to Washburn University, it contains 12 genera and at least 220 distinct species and cultivars. Magnolias are generally hardy down to USDA zone 6, and some down to USDA zone 4. They have cultural requirements for their planting site and do not like to be moved once established, but are not considered to be high-maintenance trees.
Siting & Soil Requirements
Grow your magnolia in a full-sun exposure; any overhead shade from other trees or structures will diminish bloom. Prune away any overhead trees to maximize bloom and growth performance. Protect your magnolia from wind gusts by planting windbreak trees and shrubs around it, or position the magnolia on the leeward side of a structure or group of structures. Plant magnolia in nutrient-rich and neutral-to-lightly-acidic soil, avoiding alkaline soils. Amend the soil each year with top dressings of aged manure and compost to boost soil fertility.
Water the soil around your magnolia deeply to keep it evenly and lightly moist at all times. Never allow the soil to dry out beyond 1 or 2 inches of surface soil. If the tree blooms or foliage show any sign of wilting, check the soil for dryness and irrigate immediately to relieve the drought stress. Place water a few feet out from the trunk to just past the drip line of the tree to ensure a good drenching to a depth of at least 1 foot during each watering session. Scale back watering when natural rainfall has been plentiful.
Feed your magnolia tree each year in the spring as the leaves begin to unfurl. Use a balanced, slow-release formulation with equal analysis of nitrogen, phosphorous and potassium such as a 10-10-10 or 20-20-20. Begin fertilizing young magnolia trees in their second year. Spread the granules under the canopy in a wide doughnut formation, starting at least 1 foot out from the trunk and extending to 1 foot past the drip line. Nestle the grains into the top inch of soil and water deeply.