The aliases of oleander are willow-leaf peach and half-year red.

Aliases: willow-leaf peach, half-year red

Family and genus: belongs to the Apocynaceae family, Nerium genus

Origin:

Native to Iran, now widely planted in tropical and subtropical regions; cultivated in all provinces and regions of our country.

Morphological characteristics:

Evergreen large shrub, up to 5 m tall, containing sap, hairless. Leaves in whorls of 3-4, opposite on the lower part of the branches, narrowly lanceolate, 11-15 cm long, 2-2.5 cm wide, light green beneath; lateral veins flat, densely arranged and parallel. Cymes terminal; calyx upright; corolla dark red, fragrant, double-petaled; corona scale-like, apex torn. Follicle oblong, 10-23 cm long, 1.5-2 cm in diameter; seeds with yellow-brown seed hairs at the apex.

Growth habits:

Likes sunlight, and can also adapt to a more shaded environment. Likes a warm, humid climate, is not cold-tolerant, and fears waterlogging. It has low requirements for soil, and well-drained, fertile neutral soil is most suitable, while slightly acidic or lightly alkaline soil can also be tolerated. The tree is vigorous and has strong resistance to and absorption capacity for toxic gases such as sulfur dioxide and chlorine. The base of the plant and the branches have strong sprouting ability and are tolerant of pruning.

Propagation methods:

Oleander can be propagated by three methods: cuttings, division, and layering, among which cuttings are the most commonly used propagation method.

Cuttings can be carried out in both spring and summer. Before inserting, if the base of the cutting is soaked in clean water for 7-10 days and the soaking water is kept fresh, rooting can be advanced after insertion and the survival rate increased. Water propagation can also be used throughout, soaking the base of the cutting in water and keeping the water temperature at about 20°C, changing the water frequently; after rooting, transplanting into a seedbed for maintenance also gives very good results.

In spring, girdle the bark 1-1.5 cm wide at a suitable part of a two-year-old branch, then bend it down and bury it in another pot of soil, water it afterward, keep the pot soil moist, and by late summer or early autumn cut it away from the mother plant.

Cultivation and management:

Oleander has relatively high fertilizer and water requirements and needs more applications of fertilizers such as pig manure and bean cake, with frequent watering to keep it semi-moist. At Frost's Descent, move it into a cold cellar to overwinter. At this time, fertilization is not necessary, watering can be reduced, and soil should be banked up around the roots to a thickness of 3-4 cm. When the weather warms in April, take it out of the cellar, and it blooms from April to July. After flowering, pinch the tips to encourage branching and continued blooming. Oleander can sprout 3-4 times each year and grow more than 30 cm taller.

Uses:

The stem bark fiber is an excellent blended textile raw material, and it can also be extracted to make cardiotonic agents; the roots and bark contain cardiac glycosides and phthalide crystalline substances as well as a small amount of essential oil; the stems and leaves can be made into insecticide.

In the south, oleander is suitable for group planting in parks and green spaces, roadsides, lawn edges, traffic islands, and other places, and can dress the flower-sparse summer in the new garb of "red peach and green willow." It is also suitable for planting as a pollution-resistant tree species in industrial and mining areas. Because its flower colors are gorgeous and its flowering period is long, potted ornamental display is also very suitable.

Precautions:

The leaves are poisonous and must not be eaten; accidental ingestion by humans or livestock can be fatal.