What Fertilizer to Use for a Little Gem Magnolia

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The southern magnolia is the state flower of Mississippi, here seen on a stamp.

Native to the American Southeast, the southern magnolia (Magnolia grandiflora) is among the quintessential plant emblems of the Deep South alongside live oaks and camellias. Little Gem is a smaller-sized cultivar, growing up to 30 feet tall and only 15 feet wide after several decades. Its smaller stature makes it more appropriate to use in residential landscapes, and it begins to bear its fragrant creamy white flowers at a younger age. Grow a Little Gem magnolia in U.S. Department of Agriculture plant hardiness zones 7 and warmer.

Growing Requirements

Plant a Little Gem southern magnolia in any acidic soil that is rich in organic matter, but also demonstrates good water drainage. Soil pH around 5.0 to 6.0 is ideal, and pH over 7.0 quickly leads to leaf yellowing and stunted growth. Avoid dry, nutrient-poor sandy soils and any hard, compacted clay soils. Full sun exposures promotes the most even branching canopy and the largest production of blossoms.

Soil Nutrition

Southern magnolias are always rather slow-growing, even when planted in fertile garden soils and well-maintained. Soils rich in humus or widely amended with compost or well-rotted manure usually provide ample nutrients for a healthy Little Gem tree. However, pockets of sandy or other infertile soils can arise on any property, causing a tree to falter. Applying fertilizer in late winter to early spring each year helps the Little Gem magnolia develop strong, robust new growth before the start of summer.

Fertilizer Types

Do not use liquid fertilizers on magnolia trees. Rain and irrigation after application quickly leaches the nutrients away from the Little Gem tree's broad but shallow roots. Instead, use slow-release granular fertilizer products. The granules weather away slowly over three to ten months, trickling nutrients downward to the roots after rains. Focus on well-balanced formulations, such as 8-8-8 or 10-10-10. Products with traces of micronutrients such as magnesium, iron and manganese are always beneficial.

Benefits of Mulch

While sprinkling granular fertilizer under the Little Gem magnolia tree's branches provides a nutritional boost for growth, using an organic mulch can prove nearly as effective. An acid-forming mulch--pine bark, shredded oak leaves, pine straw or coffee ground compost--decomposes to release nutrients into the soil. Granular fertilizer can still be scattered atop the mulch, but at reduced rates. The mulch adds humus to the soil, deters weeds, shades the soil and retains soil moisture, which is most valuable during the heat of summer.

Soil Testing

Don't assume you need to apply synthetic fertilizers in your garden. Conduct a soil test with the help of your local cooperative extension office to determine which, if any, nutrients are lacking in your yard. Based on the test results, you can make a more informed decision as to which fertilizer formulas, and which nutrients, are more vital to use on your property to encourage the magnolia tree's performance.

references & resources

Jacob J. Wright

Jacob J. Wright became a full-time writer in 2008, with articles appearing on various websites. He has worked professionally at gardens in Colorado, Florida, Minnesota, New York, North Carolina and Pennsylvania. Wright holds a graduate diploma in environmental horticulture from the University of Melbourne, Australia, and a Master of Science in public horticulture from the University of Delaware.