Potted oleander requires good drainage and sufficient fertility. Sprouting in spring needs pruning. For long and slender branches in plants, they can be cut off from the base. If the lumen is too dense, it is also appropriate to trim a part. At the same time, it is necessary to stick a calluses antiseptic film at the pruning mouth to protect the wound, so that the branches are evenly distributed and the tree shape is full. /kloc-Change the pots once after 0/~ 2 years, and change the pots after pruning. Summer is the period of vigorous growth and flowering of oleander, which needs a lot of water. In addition to watering once every morning and evening, if the soil in the pot is too dry, water should be sprayed again to prevent the tender branches from wilting and affect the life of flowers. After September, it is necessary to conserve water, inhibit the continued growth of plants, make branches mature, and increase the accumulation of nutrients, so as to facilitate safe wintering. The overwintering temperature should be kept at 8 ~ 65438 00℃. When the temperature is lower than 0℃, oleander will lose its leaves. Nerium indicum is a fertilizer-loving plant. Potted plants should be fertilized once a month during the growing period in addition to adequate base fertilizer. The management of oleander must pay attention to three points:
It must be trimmed in time.
The top branches of oleander have one-third characteristics, which can be trimmed and shaped as needed. If you need the shape of three forks and nine tops, you can cut off a part of the top of the fork and divide it into nine tops. If you need nine tops and eighteen branches, you can leave six branches and cut them from the axils of the top leaves to produce eighteen branches. Pruning time should be after each flowering. In the north, oleander blooms from April to October. Flowers in full bloom should be picked in time to ensure the concentration of nutrients. Generally, it is pruned in four times: one is after Grain Rain in spring; Second, between July and August; The third is the period of 10, and the fourth is winter logging. If it is necessary to bloom indoors, it should be moved indoors in the sunshine around 15℃. Prune immediately after flowering, otherwise the flowers will be few and small, or even will not bloom. Through pruning, the branches are evenly distributed and the flowers are big, bright and beautiful.
Roots must be thinned in time.
The capillary roots of oleander grow faster. Three-year-old oleander, planted in a pot with a diameter of 20 cm, can grow full of roots before July of that year, forming a ball, hindering the infiltration of water and fertilizer and affecting growth. If the roots are not thinned in time, withering, defoliation and death will occur. The best time for thinning roots is from early August to late September. At this time, the root system is dormant, which is a good opportunity to sparse roots. Alternate method: use a quick shovel to cut off the surrounding yellow hair roots; Then use a three-pointed hook to drain along the main root. About half or a third of the yellow hairy roots were removed and replanted in flowerpots. After thinning the roots, water them in the shade to keep the soil moist. Keep it cool for about 14 days, and then move to the sun. When planting oleander in the field, yellow hairy roots should also be cut around the main stem in mid-September. After cutting the roots, water and apply dilute liquid fertilizer.
Top dressing and watering must be done in time.
Nerium indicum is a flower that likes rich water and neutral or slightly acidic soil.
Fertilization: Organic soil miscellaneous fertilizer accounting for about 20% of the basin soil should be maintained. If used in chicken manure, 15% is enough. Fertilization time: once before Tomb-Sweeping Day and once after the autumnal equinox.
Methods: An annular ditch was dug at the edge of the basin and covered with soil after fertilization. After Qingming fertilization, topdressing the bean cake with water once every ten days or so; After fertilization in autumn equinox, topdressing soybean cake water or peanut cake water or ten times chicken manure liquid every ten days or so. Without the fertilizer on it, you can use human urine decomposed for more than seven days to add five to seven times of water, pour it along the edge of the basin, and then pour it thoroughly. Fertilizer containing more nitrogen should be thin, light, less and diligent in principle to prevent root burning. Proper watering is the key to manage oleander. Improper watering in winter and summer will cause defoliation, flowering and even death. Water once a day in spring and once in the morning and evening in summer to keep the soil moisture at about 50%. Always spray water on the leaves. Too dry, leaves will wither easily. You can water less in winter, but the soil moisture should be kept at about 40%. Leaves should be washed with clean water to remove dust. If it blooms in winter, the room temperature can be kept above 65438 05℃; If the flowers do not bloom in winter, the room temperature can be lowered to 7 ~ 9℃ and placed in a bright place without sunlight indoors. The oleander planted outdoors in the north needs to be wrapped with straw mats to prevent freezing and cold, and the cold-proof objects should be removed before and after Qingming. Although oleander is easy to manage, it should not be careless. In the spring and summer growing season, the terminal buds are vulnerable to aphids.
Oleander is also known as safflower oleander, willow, and half-year red. It belongs to Apocynaceae and Apocynaceae.
brown spot
Brown spot disease is an important disease on oleander, which is widely distributed in various places and has serious harm. Mainly harmful to leaves. At first, purplish red spots appear at the tip or edge of the leaf, and after expansion, round, semi-circular to irregular brown spots are formed. There are wheel tracks on the damage. In the later stage, the center fades to white and the edge is reddish brown. When the humidity is high, the gray-brown mold layer, namely the conidiophore and conidia of the pathogen, can grow on both sides of the lesion.
Prevention and cure method
(1) agricultural control.
Reasonable close planting, not too close planting; Scientific management of fertilizer and water, cultivating strong seedlings; Put an end to centralized burning of diseased leaves and reduce bacterial sources.
(2) chemical control.
Spraying 50% benomyl wettable powder 1000 times solution or 600 times solution of 25% carbendazim wettable powder and 500 times solution of 36% thiophanate-methyl suspension at the initial stage of the disease.
Commonly used drugs: benomyl, carbendazim and thiophanate-methyl.