The Best Time to Fertilize a Magnolia Bush

Young magnolia trees resemble shrubs until they mature.

When initially planting a magnolia bush, lessen the reliance on fertilization by choosing an area with acidic, moist, organic-rich soil that never floods. Once nutrient deficiencies arise, fertilizer takes weeks or months for breakdown and root absorption to correct the problem.

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.

References

• Ed Hume Seeds: Magnolias
• Mr. Grow: Frequently Asked Magnolia Questions

Resources

• Learn2Grow: Magnolia