What are the cultivation methods and precautions for oleander?

The leaves of oleander are like willow and bamboo, and its red flowers blaze brighter than peach blossoms, making it a famous ornamental flower. How do you grow oleander? Below we will look at the cultivation methods and precautions for oleander.

Cultivation methods for oleander

I. Repotting

Potted oleander needs to be repotted and have its soil changed once every two years, and a small amount of long-lasting fertilizer such as feathers and hoof and horn meal can be placed at the bottom of the pot. During the growing season, 1 to 2 applications of liquid fertilizer can be given as needed according to growth vigor. Oleander tolerates pruning and has strong sprouting ability; old plants can be renewed by pruning in spring together with repotting and soil changing, cutting all branches off from the base to encourage new shoots and rejuvenation. Generally, plants should also be pruned moderately in spring to keep the plant shape symmetrical and the tree vigorous.

II. Pruning

Through pruning, the branches are evenly distributed, the flowers are large and vivid, and the tree shape is beautiful. The upper branching of oleander has the characteristic of one splitting into three, and it can be pruned and shaped as needed. If a three-forked nine-top form is desired, part of the top of the three forks can be cut off, and nine tops will then be produced. If nine tops and eighteen branches are desired, six branches can be kept and cut from the top leaf axils, and eighteen branches will then grow. Pruning should be done after each flowering. In the north, the flowering period of oleander is from April to October. Spent flowers should be removed promptly to ensure concentrated nutrients. Generally there are four prunings: the first after Grain Rain in spring; the second during July and August; the third during October; and the fourth winter pruning. If flowering is desired indoors, move it to a sunny place indoors at about 15°C. Prune immediately after flowering, otherwise there will be few and small flowers, or even no flowers.

III. Root thinning

The fine hair roots of oleander grow quickly. A three-year-old oleander planted in a pot 20 cm in diameter can fill the pot with roots by July of that year, forming a ball that hinders the penetration of water and fertilizer and affects growth. If the roots are not thinned in time, wilting, leaf drop, and death may occur. The best time for root thinning is from early August to late September. At this time the roots are dormant, making it a good opportunity for root thinning. Method of root thinning: use a sharp trowel to cut away the surrounding yellow hair roots; then use a three-pronged hook to loosen along the main root. Remove about half or one third of the yellow hair roots, then replant in the pot. After root thinning, place in shade and water thoroughly, keeping the potting soil moist. Keep in shade for about 14 days, then move to a sunny place. For oleander planted in the ground, in mid-September the yellow hair roots should also be cut around the main trunk. After cutting the roots, water and apply dilute liquid fertilizer.

IV. Topdressing

Oleander is a flower that likes fertilizer and water and prefers neutral or slightly acidic soil. Fertilization should maintain about 20% organic mixed soil fertilizer in the potting soil. If chicken manure is used, 15% is sufficient. Fertilization time: once before Qingming, once after Autumn Equinox. Method: dig a ring-shaped trench at the edge of the pot, apply the fertilizer, then cover with soil. After fertilizing at Qingming, apply water-soaked soybean cake water as topdressing about every ten days; after fertilizing at Autumn Equinox, apply soybean cake water or peanut cake water, or ten times diluted chicken manure liquid, as topdressing about every ten days. If the above fertilizers are unavailable, human urine fermented for more than seven days can be diluted with water five to seven times, poured along the edge of the pot, and then watered thoroughly. For fertilizers containing much nitrogen, the principle is dilute, light, little, and frequent, strictly preventing root burn.

V. Watering

Proper watering is the key to managing oleander well. Improper watering in winter and summer can cause leaf drop, flower drop, and even death. In spring, water once a day; in summer, water once in the morning and once in the evening each day, keeping the potting soil moisture at about 50%. The leaves should be sprayed with water frequently. Excessive dryness easily causes leaf drop and withering. In winter, water less, but the potting soil moisture should be kept at about 40%. The leaves should often be washed with clean water to remove dust. If you want it to bloom in winter, keep the room temperature above 15°C; if you do not want it to bloom in winter, lower the room temperature to 7-9°C and place it in a bright place indoors without direct sunlight. For oleander planted outdoors in the ground in the north, it needs to be wrapped with straw mats to prevent freezing and cold, and the cold protection should be removed around Qingming. Although oleander is easy to manage, one must not be careless.

Precautions for growing oleander

Oleander likes sufficient light, warm and humid climate conditions. It is also slightly cold-tolerant, and in warm temperate regions it can overwinter outdoors without losing its leaves. In summer, potted plants should be watered and sprayed frequently to keep the potting soil and environment moist, but must not remain wet and waterlogged for long. Oleander also has another characteristic: as long as there is one instance of drought and dehydration or excessive water and waterlogging, the lower leaves of the plant will quickly all turn yellow and fall off, so watering must be timely and appropriate. After heavy pruning in early spring, attention should be paid to withholding water to prevent root infection and rot. Loosen the potting soil in a timely manner, remove flowers promptly after they fade, and in summer there are occasionally aphids and red spider mites, which can be eliminated with general pesticides. The whole oleander plant is highly toxic, and symptoms after poisoning include nausea, vomiting, lethargy, and irregular heartbeat; in severe cases, even loss of consciousness or death is possible, so when facing oleander, just admire it, and do not touch it!

To prevent root infection and rot. Loosen the potting soil in a timely manner, remove flowers promptly after they fade, and in summer there are occasionally aphids and red spider mites, which can be eliminated with general pesticides. The whole oleander plant is highly toxic, and symptoms after poisoning include nausea, vomiting, lethargy, and irregular heartbeat; in severe cases, even loss of consciousness or death is possible, so when facing oleander, just admire it, and do not touch it!