Gardening with Gary

Gardening Advice from an Expert

Oleanders

Q. Is there such a thing as an Oleander tree or does one prune the bush in such a manner as to produce a tree?

A. It seems to be a tree and is sometimes called an oleander tree, but you are correct that they are bushes which some gardeners trim to grow as a tree, with lower branches and root suckers trimmed off. If you maintain one main growing stalk or trunk, it can be grown as a tree with constant shaping and pruning. But, its general growth habit lends itself to great bushes and hedges, often grown on highway median strips for privacy and security.

Nerium oleander-Standard and Bush
Oleander Tree

These are evergreen flowering shrubs that are found wild in the Orient. They can grow up to 20 feet tall. All parts of this plant are poisonous if eaten.. They are great for cultivating outdoors in the far South. The leaves are dark green, leathery and lance-shaped; they average 6 inches in length and 1 inch wide. The flowers bloom in clusters at the ends of the shoots in the summer. They have a tubular base, but open out at the tips. They may be single, semidouble or double, and come in red, apricot, pink or white. They usually begin to bloom from March to May and continue until autumn. The Oleander, as this plant is commonly called, requires a minimum winter temperature of 45 degrees.

POTTING:
Oleanders need full sun and soil that has adequate drainage. They flourish in sandy areas. Pruning consists of cutting out dead, crowded, and unwanted growths in late winter, before new growth begins. At that time, it is wise to give them a dressing of fertilizer. Fertilizing their roots with manure or compost would be beneficial. When they are grown indoors in pots, the best soil mixture consists of two parts sandy loam and one part of equal portions of well-decayed manure and leaf mold or peat moss, with sand added freely. Repotting of small plants should be done in March and April. Older plants that are already growing in large pots or tubs aren't repotted annually, instead, they are given a yearly top-dressing with fresh compost. After repotting, they should be shaded from direct light and sprayed with water twice a day until they are established. When the weather is warm and settled and all danger of frost has passed, the plants may be set outside. Throughout the summer, these plants need a large amount of water. Setting them in saucers of water is a good way to accomplish this. When the flower buds are developing, the young shoots that develop at the bases of the flower trusses must be removed. Failure to do this is a common cause of the plants failing to bloom. As soon as the flowers have faded, the shoots of the previous year's growth should be pruned by two-thirds or more. Less water is required after they are pruned, but as they start into growth the water supply should gradually be increased. In early fall, the Oleanders should be returned to the greenhouse or other light place where they are to spend the winter. Only enough water is needed throughout the winter to keep the leaves from shriveling.

PROPAGATION:
Cuttings, 3-6 inches long, made from the firm shoots are cut off during the summer. Remove the lower leaves and cut the bottom of the stem cleanly across just beneath a joint (node). Insert them into a bottle or jar of water with their bases just beneath the surface of the water. The bottle may be placed in the sun. They may also be rooted in sand, a mixture of sand and peat moss, or in vermiculite. A bell jar or mason jar is placed over them until they form roots. After the cuttings root, whether in water or soil, they are planted in 3-inch pots and later, in larger pots. The tips of the shoots should be pinched off as soon as they are planted in the 3-inch pots and the following side shoots should be pinched when they are planted in 5-inch pots so to encourage bushy growth.

VARIETIES:
N. Oleander (red) and its varieties:
album plenum (double white)
Henri Mares (double rosy-pink)
splendens (double red)
variegatum (red w/ variegated leaves)
Apple blossom (shell pink)
Scarlet Beauty (brilliant red)
Mrs. Roeding (double salmon pink)
Soeur Agnes (double white)

N. indicum: This and its varieties have double flowers that are very fragrant. They usually don't grow over 8 ft. The flowers vary from rosy-pink to white.

Assistance from: http://www.botany.com/nerium.html