February 2020 Articles

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Japanese magnolia flowers spring to life

Japanese magnolia flowers spring to life Editor: Rick Bogren at 225-578-5839 or rbogren@agcenter.lsu.edu By Heather Kirk-Ballard LSU AgCenter Horticulturist Japanese magnolias are in bloom everywhere right now, possibly signifying an early spring. It’s one of the most strikingly beautiful blooming trees this time of year. Also known as saucer magnolia, it is a small, deciduous shrub (botanically speaking) but grows tall. It can be trained like a tree to grow from one main trunk, similar to the way crape myrtles are grown. The tree is a hybrid cross of two species of magnolias, M. liliiflora and M. denudate, and its Latin name is Magnolia x soulangeana. And as luck would have it, this is the perfect time of year to plant them. Local nurseries usually carry more than one variety, and many are available to choose from. It can get confusing keeping up with the many types and crosses of magnolias. The most common varieties of Japanese or saucer magnolias are Alexandrina, which has flowers that are deep rose-purple with white inside; Lennei, which has a dark purple flower with white inside; Lennei Alba, which is pure white; Rustica Rubra, which has rose-red flowers; and Verbanica, which has pink flowers with white inside. Other gorgeous magnolia crosses are also in bloom this time of year. They include loebnar magnolia and star magnolia stellata. The Little Girl series originated at the National Arboretum in the 1950s and are a hybrid of Magnolia liliiflora Nigra crossed with Magnolia stellata Rosea. They come with adorable names such as Ann, Betty, Jane, Jon, Judy, Pinkie, Randy, Ricki and Susan. Many of these named varieties can be found at local nurseries. All of these magnolias are small, deciduous trees that bloom in early spring and boast many colors from the deepest magenta purple to pink to creamy white. There are even yellow-colored varieties called Elizabeth and Judy Zuk, but finding them can be likened to finding a needle in a haystack. What’s especially striking about these magnolias is they flower before leaves emerge. Gorgeous blooms on barren stems is the quintessential image of spring, in my mind. Large, fuzzy gray buds break, followed closely by gorgeous tulip-shaped blooms that open into little saucers shapes of delicate pink to white colors. All are relatively small trees, growing only to 25 to 30 feet tall by 20 feet wide and are multi-trunked unless trained to one major trunk. They grow best in full to partial sun in well-drained, slightly acidic soil. Be sure to water in well after planting, followed by routine watering the first couple of weeks for best establishment. Water during droughts in the first year. Skip fertilizer in year one, but begin fertilizing in the spring of year two. Magnolias prefer a loamy soil with a lower pH of 5.0 to 6.5, but they can tolerate alkaline soils. Iron and manganese chlorosis can be an issue in soils with high pH. This yellowing of the leaves can be corrected after soil tests confirm an iron or manganese deficiency by applying elemental sulfur to help lower the pH. Fertilize with ferrous (iron) sulfate if iron is deficient. You may apply a water-soluble, complete fertilizer with micronutrients at the recommended rates to combat manganese issues. Trim branches to keep the tree looking tidy, and keep the many trunks trained to either only one trunk or just two or three. It’s best to prune after flowering. Be sure to mulch at a 2-to-4-inch-thick layer because magnolias are shallow rooted. Mulch helps moderate soil temperatures and conserve moisture. Scale is the main insect problem for magnolias. Use a horticulture oil in cool weather to help with control. Once weather heats up, use another type of organic spray for control because oil on the leaves can burn the plant in intense sun. These magnolias have a slow to moderate growth rate and make a great accent specimen or foundation tree for framing the house. Be sure to plant them a good 10 feet away from the house or awnings. The flowers are extremely fragrant and make gorgeous cut flowers to bring in, arrange and enjoy. The room will be filled with spicy, sweet, invigorating scents, and the colors will warm your home.