How to Care for Magnolia Flowers in Minnesota

Magnolia flowers blooming in southern Minnesota

Because Minnesota is split between USDA Hardiness Zones 3 and 4, magnolias should only be grown in the southern half of the state, mostly south of St. Cloud. North of that, it's too cold in the winters for magnolia to survive. Choose from the hardiest varieties of magnolia, even if you're planting in the southern part of the state. Star, Merrill and Cucumber Tree magnolias are most likely to thrive in Zone 4 regions of Minnesota.

Things You'll Need

• Shovel
• Peat
• Sand
• Garden soil
• Water
• Fertilizer
• Pruning shears

Instructions

1. Plant magnolias in full sun during the fall, while the tree is dormant. Place them 15 to 20 feet from a sheltering wall. The southern exposure of a house or other building is ideal. Magnolias need plenty of light to flower well, and will benefit from walls that block northwest winds in the Minnesota winter.

2. Keep soil cultivated and well-drained. Magnolias will not flourish if planted in compacted, clay soils. Amend soil with equal parts peat, sand, and garden soil to keep water from collecting around roots and rotting them.

3. Give magnolias a steady supply of moisture during the growing season, especially during the hot months of July and August. Watering once a week should be sufficient, unless you see signs of wilting.

4. Fertilize magnolias annually, after they bloom, as the tree begins to leaf. in Minnesota, this should be the third or fourth week of May. Use a balanced fertilizer with nitrogen, potassium, and phosphorus. Apply it according to the instructions on the package for the size and age of the tree.

5. Prune the lower branches of magnolia with pruning shears as it grows to reveal its twisting grey trunk. Pruning lower branches will concentrate the tree's energy in the canopy, producing height and more flowering.

Tips & Warnings

• Enjoy the bloom of magnolias during the first two weeks of May in Minnesota. No special care is required during the flowering stage.

• If your magnolias are well-watered but still wilting, chances are the soil is not properly amended. Check to see that water drains quickly when you pour water on it. If it pools, you must add more peat and sand to the soil and carefully cultivate it down toward the roots.

References

• USDA: Minnesota Plant Hardiness Zone Map
• University of Minnesota: Magnolias for Minnesota
• Clemson University: Magnolia

Resources

• University of Minnesota: Trees, Shrubs & Vines for Minnesota Landscapes
• Iowa State University: Spectacular Spring Flowering Shrub