Southern magnolia (Evergreen magnolia, magnificent laurel magnolia, loblolly magnolia, Bull Bay, Big Laurel) grows up to impressive 90 feet (27.5 m) tall. It is well-known for creamy-white flowers, which spread a lemony-like scent around the tree throughout the summer. As an excellent backdrop for large blooms, there are lustrous, leathery, oval-shaped evergreen leaves.
Can you imagine opening your eyes early in the morning, and the first thing you see is a treetop full of beautiful cup-shaped blooms flowers? They usually open about 9:00 am and close at night for approximately two or three days. After the flowers re-open, they turn brown and finally disintegrate. Wilted flowers produce cone-like seedpods with large, red seeds.
The Most Popular Types of Magnolia
Southern magnolia (Magnolia grandiflora)
You can find this type in warm regions of the US. This flower originated in southeastern North America and came to Europe in 1731 for the first time. It adapted to the new climate almost immediately.
I adore its large, elegant, fragrant, 8 inches (20 cm) long white flowers and glossy, 5 to 8 inches (13 – 20 cm) long evergreen leaves. After blooming, you can enjoy reddishly, 3 to 5 inches (7.6 – 13 cm) long, oblong-shaped fruits ripening in autumn.
Star magnolia (Magnolia stellata)
This cold-hardy, slow-growing type thrives in colder areas and can reach approximately 15 feet (4.6 m) height. It begins blooming while it is still very small. White flowers are about 3 to 5 inches (7.6 – 13 cm) long, with 12 to 40 petal-like ‘tepals’ arranged as stars. The foliage is dark green, 4 to 8 inches (10 – 20 cm) long on average.
Saucer magnolia (Magnolia × soulangeana)
This large-flowered hybrid Magnolia is a small deciduous tree with a moderate growth rate. It can reach 40 to 70 feet (12 – 21 m) height. Saucer magnolia impresses everyone with its spectacular white, pink, or purple flowers appearing in early spring before 3 to 10 inches (7.6 – 25.5 cm) long leaves.
Champaca magnolia (Magnolia champaca)
Since it is native to southeastern Asia, you can grow this type if you live in tropical regions of the US. It can reach about 30 feet (9.1 m) height but may grow even larger over time.
The highly fragrant, small, creamy-white or yellow flowers of this plant form all along the branches and flourish from spring to the end of summer.
How to Plant Southern Magnolia in Your Garden
The best time to plant your lovely Magnolia is in early spring. You have two ways to do that. If you decide to grow the tree from cuttings, you can be sure that you will get an identical plant to its parent tree.
On the other hand, if you want to try sowing seedlings, the process will be faster, but you can’t be sure what you will get in the end. It is possible to get a different shape of the tree and variable color of blooms and leaves.
When to plant Magnolia
The best time to plant your new tree in spring or fall when there are enough rains to encourage healthy and vigorous growth. If the weather is warm and without precipitation, you should water your seedlings two to three times a week for the first six months.
How to plant Magnolia
Use a garden hoe and dig a hole, which should be as deep as a root ball and at least two to three times wider. Place the native soil into the hole, but add mushroom compost, cow manure, sand, or a planting mix if the ground is poor quality.
Gently loosen the root ball and remove the plant from the container it was growing in. Set the seedling in the hole, but take care that the root ball is 1 inch (2.5 cm) above the level of the ground to allow settling.
Fill the hole with the chosen soil mixture and try to remove air pockets at the same time. Water it abundantly when the hole is half-filled. Then finish the job. Don’t forget to use garden gloves to protect your hands during work.
To extra boost forming the roots and its strong development, you can water your young tree with a solution of root stimulator.
Also, place 1 to 4 inches (2.5 – 10 cm) thick layer of peat moss, pine straw, or chipped wood on the top to help with moisture retention. It will be especially helpful when the ground is not adequately drained.
How to Care Southern Magnolia in Your Garden
Provide enough space for your Magnolia with fertile, loamy, moist, well-drained, and acidic soil. The best pH is in a range of 4.5 to 6.5. If you are not sure about the pH of the ground in your garden, get it tested before planting this tree.
Apply sulfur, chelated iron, or aluminum sulfate if it is necessary to make the soil more acid. However, if you prefer a more natural solution, add organic compost to increase acidity.
Also, it is an excellent idea to test the drainage of the soil. Dig a hole about 12 inches (30.5 cm) in diameter and fill it with water. After it drains, add water again and measure how long water takes to remove.
The water level will go down in well-drained soil at a rate of about 1 inch (2.5 cm) an hour. Loose and sandy soils have a faster rate, which means that you should add organic compost to help retain moisture. When that rate is slower, your ground is not drained well, and you should improve drainage.
Your Southern magnolia needs at least five hours of sun daily. A young tree can tolerate partial shade, but the older plant will require more sun over time.
The way to determine if your plant gets enough sun is the foliage. When the amount of sun is satisfying, leaves become denser.
Your Magnolia will tolerate the hot temperatures up to 107 F (41.5 C), but can’t stand cold weather and frost. The interesting thing is that the winter sun may do more damage than coldness.
Magnolia, especially a newly-planted one, needs a lot of water. You should deeply water your tree about three months after planting. Once established, your plant will become drought-tolerant. That means that after that period, watering will be necessary only during a long period without rain.
Until becoming well-established, watering of young Magnolia will directly depend on the temperature. As long as the temperature is below 70 F (21 C), you don’t need to water your plant more than a few times a month. While the temperatures are from 70 to 80 F (21 – 26.7 C), you should begin watering once a week.
Water your tree twice a week while the temperatures are from 80 to 90 F (26.7 – 32 C), and keep watering every other day once when the temperatures are over 90 F (32 C).
The best solution is using an automated irrigation system. However, a garden hose with 20-minute intervals between two watering is an excellent option as well. That way, the soil will be moist enough, but not soggy.
Always water your tree early in the morning. Avoid doing that in the late evenings to prevent fungal diseases. Keep in mind that deep soaking the plant is more efficient and healthier than everyday splashing.
Southern magnolia is a light feeder. After your tree establishes, you can start following a schedule of fertilizing during the first three years.
In the beginning, feed your plant, the best in March, May, July, and September with 0.5 pounds (227 g) of 8-8-8 or 10-10-10 fertilizer per 10 sq ft (0.9 m2). Increase the rate to 2 pounds (0.9 kg) by the third year.
Starting from the fourth year, it will be enough fertilizing your tree once or twice a year. Stop feeding approximately two months before the first frost to avoid damaging new growth.
To keep the soil moisture and keep your plant weed-free, you should add 4 inches (10 cm) deep layer of mulch around the base of the Magnolia tree. The best options are leaves, pine bark, and pine straw. Take care to place it slightly away from the tree trunk.
It’s up to you if you will decide to grow your Magnolia as a single-trunk tree or a multi-trunk form. Depending on your decision, start shaping the tree while it is still young. Prune side branches once or twice a season to get the desired growth form.
However, I prefer a more natural look and allow my Magnolia to branch all the way to the ground. I just take care to remove all broken and damaged branches.
No matter which style you like more, always prune your tree after blooming and during the period of dormancy in autumn. Some gardeners prune their plants in mid-summer to give them time to heal before the cold period of the year comes.
Use a sharp pair of bypass pruning shears for branches up to 1 inch (2.5 cm) thick. If you want to cut thicker branches, you will need a lopper pruner. In both cases, you need to make smooth cuts that will heal faster.
Keep in mind that your tree can bleed from ‘wounds’ and skip flourishing the next season if you cut it too much.
While Magnolia is young, you need to support it by placing adequate wood stakes around. That will help the tree to stabilize during the early period of growth.
Southern Magnolia Pests and Diseases
Algal leaf spot
Once this disease appears, you will see velvety reddish-brown areas on the upper side of leaves. At the same time, awful, hair-like structures develop on the undersides.
However, it is not a severe condition, and you don’t need to cure the tree unless you have a problem looking at ugly foliage. Try to water and feed your tree correctly, which is usually everything your Magnolia needs. If you decide to treat it, apply an appropriate fungicide.
This disease will jeopardize your tree by causing girdling of branches. Usually, one branch dies suddenly even though the rest of the tree is healthy. Solve the problem by pruning that particular branch, as well as parts with unusual knots or the peeled off bark.
Fungal leaf spots
This condition implies the appearance of stains, which can vary in colors, shapes, and sizes. You don’t need to cure these spots if they affect just a surface of the leaves.
It will be enough cleaning up dead foliage and keeping maintaining the tree adequately to minimize the risk of spreading disease.
This issue can affect the inside of your tree or its base. If you notice the disease early enough, you may save your plant. Pay attention to wilting parts and leaking spots on the bark.