Container growing magnolia trees gives you a level of control that you can use to your advantage to get the best tree possible. It allows you to move the plant around to get the full sun it needs and also lets you keep it indoors to shield it from severe weather. This is especially helpful when the magnolias young.
Note that not all magnolia trees can be planted in containers, but the smaller ones (around 10 feet tall) will do well being incubated in this way.
Step 1 - Choosing the Right Species
The star magnolia, ann magnolia, and southern magnolia (Little Gem cultivars) are all species that are recommended for indoor growth. The saucer magnolia is bigger than the rest, but horticulturally speaking, it can still be planted in a container if you have one big enough.
NOTE:: Even though you’re growing small varieties of the magnolia tree, it’s still a tree so it will be very dependent on you and crave significant amounts of water and fertilizer.You may be growing from within a container, but a tree will have more complex roots and definitely require more attention than a simple flower or bean sprout that is being grown indoors.
Step 2 - Choosing the Right Container
The root system of a magnolia is quite intricate and fast-growing. A container that is too small will squelch your roots and kill your tree. A general guide for choosing a vessel is that for each inch your mature tree will measure in diameter, a whole foot should be set aside for the vessel’s width and height.
For example, if a tree is 4 inches in diameter at maturity, plant in a container that is 4 feet wide and 4 feet deep, a foot for each respective inch. Make sure there are plenty of holes at the bottom of your container so that the water will drain well.
Step 3 - Planting Your Magnolia
Place several inches of rocks at the bottom of your container to make sure it is heavy enough. This will also help the water to drain better. Fill with a compost soil that has been mixed with manure, peat moss, and/or sand. Leave several inches of room at the top of the vessel. This will get filled in with mulch.
Dig a hole twice as wide as the root ball, and plant the magnolia so that the top of the root ball is level with the surface of the soil. If you’re planting from a seed, cover seeds so they’re at a depth of 1/2 inch and allow to germinate for about four weeks.
Step 4 - Staking and Mulching
Top the containers soil with several inches of leaves, pine straws, and/or bark. Drive a wooden stake into the container next to the tree and secure the tree to the stake.
Warning: be careful not to puncture or damage the root system when placing the stake
Step 5 - Place in a Sunny, Sheltered Spot
Place your magnolia tree in a place where it can receive full sun, about eight hours a day. It should also be in a spot where it will be sheltered from the wind. The magnolia ann blooms later than other magnolias and will be more frost-resistant when placed outside.
Step 6 - Feeding and Watering
Water immediately after planting in container. Water weekly or whenever the top couple inches of the container soil are dry to the touch. Fertilize monthly with a liquid acid fertilizer. There are actually some fertilizers especially made for magnolias.
Be sure to make use of your container privileges and move your magnolia around so that it can be admired and enjoyed as much as possible before it grows large enough to be transferred.