Spring
Mulch is very important to magnolias. Spread a 2 to 4 inch thick layer of some attractive organic material such as wood chips, shredded bark, or chopped leaves directly on the soil around the base of the tree. The circle of mulch around the tree trunk should be at least 2 feet wide when it is young, and somewhat wider as it matures. A living mulch of groundcover such as pachysandra will provide the same protection. Not only will this protect fragile magnolia bark from lawnmower and weed trimmer damage, but will discourage weeds, help the soil retain moisture, condition the soil and harbor beneficial organisms. Renew the mulch layer as it decomposes over the season. A 4-inch layer will insulate the soil against the alternately freezing and thawing temperatures in the winter which often heaves the soil, disturbing plant roots. For more information see the file on Using Mulch
Summer
Newly planted magnolias require a lot of water. They grow slowly the first year they are planted because their roots are struggling to recover from transplant shock. If the trees are permitted to dry out during this time, they may die. Once they are well established, magnolias need supplemental watering only in periods of drought or if their soil is poor and does not retain moisture. For information on products see the file on Choosing Watering Equipment
Prune the occasional damaged branch promptly. Cut off any branch that crosses and rubs another and vertical water sprouts or suckers along magnolia branches. Prune for size and shape immediately after flowering, as new buds form over the summer for next year’s show. For more information see the files on Pruning Shade and Flowering Trees and Choosing Pruning Tools
Fall
Feed young magnolias once a year in the fall. Sprinkle all-purpose slow-acting granular fertilizer on the soil under the tree out to 1-1/2 feet beyond the tips of the branches (the dripline) for the rain to soak in. Do not allow it to touch the trunk. A rule of thumb is about 1 cup or 1 pound of fertilizer for every inch of trunk diameter measured four feet up from the base of the tree. After several years established magnolias do not need annual feeding, especially if they have been mulched with organic material that has decomposed and enriched the soil over the root zone. For more information see the files on Fertilizing Trees and Choosing Fertilizers
Winter
Magnolias require little winter pruning, except to remove water shoots that spring up along the branches and to maintain shapeliness. To encourage a tree form, rather than a shrubby look, remove some of the lower branches and extra stems. When cutting a branch, be sure to cut it all the way back to, but do not include, the collar of bark that circles it at its base. This will discourage the development of nuisance the fast-growing vertical water shoots that spoil the lines of the tree. Use clean, sharp hand pruners or loppers to make a clean, smooth cut that will heal nicely. Magnolias are prone to wood diseases that infect through jagged open wounds. Pruning Shade and Flowering Trees and Choosing Pruning Tools
