In the spring garden, the star magnolia is a real show-stopper. Understandably, gardeners and landscapers alike are drawn to this little, deciduous tree with its abundance of star-shaped white blossoms that develop before the leaves.
If your yard is blessed with a star magnolia, you will want to make sure it receives the right upkeep and care so it will flourish for many years to come. In this extensive guide, we will go over all you need to know to maintain the finest possible appearance for your star magnolia.
Key Takeaways:
- Site star magnolias in full sun to partial shade and well-drained, acidic soil amended with compost or peat moss
- Water deeply weekly for the first year, then every 7-10 days, and apply 2-4 inches of mulch
- Fertilize annually in early spring with an acidic fertilizer or compost/manure top-dressing
- Prune in spring after blooming to shape, remove dead wood, and thin out overcrowded branches
- Monitor for potential issues like magnolia scale, leaf scorch/blight, cankers, or root rots
- Protect young trees and flower buds from harsh winter cold/winds and late spring frosts
- Explore unique cultivars like ‘Centennial’, ‘Rosea’, ‘Rubra’, and ‘Waterlily’ for added interest
You can have an amazing springtime blossom display from your star magnolia for many years to come with the right planting, soil preparation, watering, fertilizing, trimming, and protection. This magnificent tree will be the talk of your garden if you give it regular maintenance!
Site Selection and Planting
Like other plants, star magnolias need a certain kind of setting in order to flourish to their full potential. They require at least 4-6 hours of direct sunshine every day, and they prefer full sun to partial shade.
The amount of solar exposure increases with the abundance of flowers. In terms of soil, organic matter-rich, slightly acidic soil that drains well is ideal for star magnolia growth. Before planting, think about enriching your heavily clayey or highly alkaline soil with compost, peat moss, or other organic resources.
Remember that star magnolias can grow up to 20 feet tall and wide when selecting a planting spot. To allow for future growth, plant them at least 8 to 10 feet away from buildings, utilities, or other trees and plants. Planting should be done in the early spring, before bud break.
Dig a hole that is twice as broad as the root ball, but not deeper, to ensure that your star magnolia gets off to a strong start. Remove any ropes, burlap, or wire baskets that are surrounding the root ball with care.
After loosening the outer roots gently, plant the tree in the hole, making sure it is straight and planted at the same depth as it was in the burlap or nursery pot. To eliminate any air pockets, gently firm the original soil before backfilling it. Lastly, to help with irrigation, build a berm or soil ring around the outside of the planting hole.
Watering and Mulching
Establishing a healthy star magnolia requires proper watering, especially during the first two to three years of growth. The soil should be continuously moist but not overly wet. Give the plants 1-2 inches of water each week during the growing season in the first year after planting (more during hot, dry periods). After that, thorough waterings should be sufficient every ten to fourteen days, unless there is a drought.
Apply a 2-4-inch layer of organic mulch, such as wood chips, shredded bark, or pine needles, around the base of the tree to help retain soil moisture and discourage weed growth. To keep the mulch at this level, replenish it as needed, being careful not to let it come into direct contact with the trunk.
Fertilizing
An annual feeding in the early spring, right before new growth appears, is beneficial for star magnolias. Use an acidic fertilizer designed for trees and shrubs, and pay attention to the label’s recommendations for the right amount to apply based on the size of your tree.
Cottonseed meal, acidifying nitrogen fertilizers, and unique fertilizer blends that love acid are a few examples of appropriate fertilizers. Apply fertilizer evenly across the canopy of mature trees and thoroughly water afterward.
As an alternative, you can top-dress the area around the tree’s drip line every spring with 1-2 inches of compost or well-rotted manure. This organic matter will give your star magnolia roots with a slow-release source of nutrients as it decomposes.
Pruning
Regular pruning isn’t strictly necessary for star magnolias, but you may want to prune for any of the following reasons:
- Shaping and controlling size
- Removing crossed, damaged, or dead branches
- Thinning out overcrowded interior branches
Right after the tree’s springtime blooms end is the ideal time to prune. This preserves the late-summer flower buds for the following year and lets you view the branch structure more clearly.
Just above an outward-facing bud or branch, make cuts using sharp, clean pruning scissors. When pruning, attempt to keep the tree’s natural symmetry and branching form. Remove longer stems and branches from the interior of the canopy to reduce size. A young star magnolia’s core leader should never be pruned or severed.
Pests and Disease
Star magnolias are generally problem-free compared to many other trees. However, their susceptibility to certain pests and diseases varies by geographic region. Some potential issues to watch for include:
- Magnolia scale – These small sucking insects can coat branches and leaves. Use horticultural oil or insecticidal soap for control.
- Leaf scorch or summer blight – Hot, dry conditions stress the tree, causing leaf browning and premature defoliation in summer. Proper irrigation is key to prevention.
- Canker diseases – Look for sunken areas of dead bark that may ooze sap, indicating a fungal canker disease. Prune out cankered branches.
- Root rots – Overly wet soil can lead to mushroom root rot or other soil-borne fungal diseases. Improve soil drainage and limit overwatering.
Generally speaking, most pest and disease problems may be avoided by giving your star magnolia enough water and mulching.
Winter Protection
Once established, star magnolias, which are hardy in USDA Zones 4–8, can withstand winter cold quite well. Young trees or those that are in exposed areas, however, would require protection from the severe winter winds and desiccation. Frosts in late April can also cause damage to the enormous flower buds.
You can cover the lower branches and trunk of the tree with burlap for the first few years, or you can temporarily cover the west and south faces of the tree with a windscreen. Late autumn trimming and tree transplanting should be avoided as this encourages new growth that is more susceptible to cold harm.
Another option is to create a protection cage around your star magnolia before winter. Use posts and burlap or scrap wood/wire fencing to enclose the entire tree. Fill the cage with leaves, mulch, or straw for insulation. Remove the cage in early spring once severe cold has passed.
When early blooms emerge, pay close attention to late frost forecasts. If freezing temperatures are predicted overnight, quickly cover the tree with a frost blanket or tarp and remove it the next morning. Hot caps or string lights wrapped around branches can provide added frost protection as well.
Cultivars and Companion Plants
Now that you know the basics of caring for star magnolias, why not expand your horizons with some choice cultivars? A few standouts include:
- ‘Centennial’ – One of the hardiest varieties, with an upright, pyramidal shape and fragrant white blossoms.
- ‘Rosea’ – Features pale pink or reddish-purple flowers. Stunning accent tree.
- ‘Rubra’ – Deep purple-red flowers on a dense, rounded shrub form.
- ‘Waterlily’ – Large cup-shaped white flowers resembling water lilies. Compact, multi-stemmed habit.
Consider underplanting spring-blooming perennials or bulbs, such as hellebores, grape hyacinths, or daffodils, to go with your star magnolia.Rhododendron or low-growing azaleas make excellent pairings as well. Add contrasting shapes, such as ornamental grasses, erect evergreen shrubs, or plants with aggressively textured leaf, for extra year-round visual interest.
Every spring, the star magnolia is sure to draw attention with its extravagant flower arrangement. If you take the necessary care of this little specimen tree, you will be rewarded with an amazing
blossoming display every year. The star magnolia is a wonderful garden gem, whether you plant it as a solitary accent tree or include it in a mixed border. Today, give your landscape some star power!
