Magnolias reward the gardener with year-on-year increasing beauty. They are very easy to grow in any soil that is not very alkaline, and enjoy clay soils provided they have been well prepared.
The most important rule is to remember that they will not tolerate deep planting or prolonged periods of waterlogging. If in doubt, plant shallow, or mound plant, incorporating reasonable amounts of organic matter and a little slow release fertilizer (too much is worse than none at all). Mulch in spring, but avoid the mulch building up to such an extent that the tree becomes deep planted.
The roots of magnolias are fleshy and brittle, and, if broken, can rot back to the bole, so treat the roots with great care when planting and do not stamp down too hard on the newly planted tree! Stakes should be driven in at an angle and never be forced through the root ball.
Magnolias, except for the large leaved American varieties, are wind tolerant, and all will tolerate anything but the deepest shade, though flowering will be reduced in shade.
Avoid planting out newly acquired plants until the danger of frost is over - the new leaves are damaged by late frosts, and under extreme circumstances, in which all the new growth is frosted, the plant may die. Protection from late frosts is therefore desirable for smaller plants.
Slugs and, more particularly, snails, love the young leaves, so employ your usual measures to prevent attack on small plants. Magnolias are quite resistant to honey fungus. Deer can damage trunks, branches and shoots, so protect up to five feet with wire netting if deer are a problem in your garden.
Collect the seed in the autumn, just as the carpels begin to split. Keep inside the house, and let the carpels open but never let the seed dry out totally. Extract the red or yellow coated seed, and put into a jar of water to which a few drops of Fairy Liquid (or similar) has been added. This softens the coating. Extract the black seeds. Unless you are very short of seed, discard any that float on water. Place in a polythene bag with a little moist (not wet) moss peat and put in the bottom of the fridge for at least 90 days, or until they can be sown at a convenient time.
Sow sparsely in pure peat, and let them warm up to about 70F in the house, greenhouse or wherever! Germination will be sporadic over a month or so, though some seed does not germinate until 12 months have passed. Prick out into pots as soon as two good true leaves (in addition to the cotyledons) show, and re-pot as soon as the roots reach the bottom of the pot. Keep in shade, don't overwater or let them scorch, which they will do at high temperatures even in shade. 70 to 80F is ideal. Re-pot again when the roots begin to fill the pot. Some seedlings will make a metre of growth in the first season, but the average is a third of this, depending on the variety.
Frost should never be allowed to get to the roots of seedlings, so they should not be left outside during winter.
Some magnolias will root from half ripe cuttings whereas others must be grafted or chip budded. As a general rule, any cultivar which has Magnolia liliiflora in its make up stands a good chance of rooting. If the tips of half ripe shoots are still soft they should be cut down to the highest node which is reasonably firm or the cutting will rot back. A compost of 50% Cornish grit and 50% peat gives reasonable results. High humidity is essential, and try to maintain a temperature of about 70F. Rooting takes a few months. Overhead lighting is a considerable advantage, particularly in getting the rooted cuttings into growth.