The Best Time to Fertilize a Magnolia Bush

Significance

• Magnolias develop shallow root systems, so they obtain nutrients near the soil surface to satisfy growth needs. Acidic soils ensure certain nutrients are most available to roots. Overall, magnolias grow best in rich soils containing ample nitrogen, iron, magnesium and sulfur.

Time Frame

• Scatter well-balanced, slow-release granular fertilizers atop the soil all around the magnolia bush in late winter to very early spring, just before buds swell and open. The granules begin to decompose to release nutrients before new leaves grow. A light application in fall after the first killing frost also benefits roots.

Considerations

• Maintain a 3 to 4 inch layer of organic mulch atop the root zone of the magnolia. This decomposing humus keeps the soil moist and supplies nutrients to the roots year-round. Extend the mulch 3 to 6 feet beyond the branch tips where the youngest, vigorous roots dwell.

Warning

• Planting a magnolia in nutrient-poor, non-acidic soil greatly increases the need for proactive fertilization. This is particularly true in sandy soils that lack any organic matter.