Poinsettia, also known as holy saliva, is a famous potted flower, which people watch on New Year's Eve. It belongs to Orchidaceae and is evergreen and slippery. This flower is native to Mexico and Central America, and now it is cultivated all over China. It likes sunny, mild climate, fertile and soft slightly acidic soil. Poinsettia likes warm and sunny environment and is not cold-resistant. The optimum growth temperature is 22℃~ 27℃, and the winter temperature is above 65438 05℃. Poinsettia is mainly propagated by cutting, and generally it is easy to survive from May to August. The cuttings used should be stout branches with yellow-brown stems and smooth skin, with a length of 65,438+00 cm to 65,438+05 cm and 3 to 4 leaf buds. The cuttings are cut into inclined planes, and the insertion depth is 1/2 cuttings. After the cuttings are inserted, water them, move them to a ventilated and cool place, and cover them with plastic bags for insulation. The cultivated soil should be loose, nutritious and high in fertilizer efficiency. Mix 5 parts of natural humus soil, 3 parts of garden soil and 2 parts of bean cake, spray 600-800 times of 50% thiophanate-methyl solution or 50% carbendazim wettable powder for disinfection, and put it into a pot after 24 hours. Poinsettia is very sensitive to water, afraid of dryness and waterlogging. Uneven watering can cause adverse reactions. Leaves will curl when dry, and become soft and drooping when waterlogged. At the initial stage of growth, the temperature is not high and the water is less. In summer, the temperature is high, the leaves are big, the water consumption is large, and there is more water. In addition, it is necessary to replenish water according to the actual situation. Poinsettia likes fertilizer, but the fertilizer and water should be properly controlled in the early stage of growth to avoid excessive growth and long internodes. Generally, the effect of fermented cake fertilizer is good When it is close to flowering, phosphate fertilizer should be added to make the bracts bigger and brighter. Poinsettia is a light-loving plant, so it should be placed in a sunny place, and the pot should not be too crowded to facilitate ventilation and avoid vain growth. After the position of the pot is fixed, don't move often, otherwise it will affect the growth. Poinsettia began to differentiate into flower buds in late June, with 65438+ 10 month, and it can bloom in about 60 to 70 days. If you want to blossom ahead of time, you can do short-day treatment, shade with a double-layer paper cover from 5: 00 to 8: 00 every evening, and pick it off after 8: 00, so that the buds will bloom in 40 to 50 days. After a pint of safflower withers, all branches should be pruned immediately, leaving only two base branches to put the plant into dormancy. After re-cutting, the pot should be placed in a warm place indoors, stop watering and fertilizing, let it sleep, only pour less water on the surface of the pot, and move it outdoors for normal management in warm spring.

Potted poinsettia pot soil should be matched with 7 parts garden soil, 3 parts decomposed cake fertilizer and green bran ash; Or 2 parts of garden soil, humus soil 1 part and compost 1 part. After the seedlings are potted, they should be given enough water and placed in a semi-cool place for about a week, then moved to an outdoor place where the sun can be seen in the morning and evening, and then placed in a sunny place for maintenance for about half a month. When the seedlings grow to 15 cm, they must be enucleated. Leave 4-5 leaves from the base, and cut off the branches to make 3-5 lateral branches grow from the base. When the branches grow to 15-20 cm, they can start to make curved shapes.

The whole growth process of poinsettia needs uniform water supply, which is both afraid of drought and waterlogging. The evaporation in spring and autumn is small, so watering should be controlled; There is a large amount of evaporation in sunny days in summer, so water should be poured once every morning and evening. Generally, the basin soil should be watered after it is dry. Water before noon in winter, and water in the afternoon will lower the soil temperature.

Poinsettia needs higher fertilizer, especially nitrogen fertilizer. In the growing period, if nitrogen is insufficient, the phenomenon of fan leaves will appear. Therefore, topdressing should start 7- 10 days after coring. It is advisable to apply light fertilizer late and avoid applying thick fertilizer once a week. Move indoors before cold dew, give sufficient light and ventilation, and keep the room temperature above 15℃. After the bud appears, when it is close to flowering, more phosphate fertilizer should be applied to make the bract leaves (flowers) colorful. After flowering, lowering the temperature to 65438 02℃ can prolong the flowering period.

Poinsettia is a short-day plant, which blooms naturally from June to February in 5438. If you want it to blossom in advance, you can treat it with short sunshine, that is, from the beginning of August, shorten the daily illumination time to 8-9 hours, so that it can blossom shortly before the National Day.

How does poinsettia make a curved shape?

Poinsettia plants grow very fast and are easy to grow white, which makes the plant type high. To this end, many flower farmers make it into an arc. Generally, start from the branch length of 18 cm, and do not water it two days before bending. The operation time should be around 6 pm, because the poinsettia is exposed for one day, and the water content of the branches decreases accordingly and becomes soft. If you bend down in the morning, the branches are brittle and easy to break. Bend the branch into an arch with a string and fix it. You can bend in different directions once every once in a while, and tie the branches into a spiral that hovers around to make the plants shorter. The last bend should be about 20 days before flowering. When doing bending modeling, pay attention to the requirement that the strong branches are placed around, the weak branches are placed in the middle, and the strong branches bend downward to a greater extent, so that the branches and leaves of plants can be evenly distributed, highly consistent, the flowers are neat, and the whole tree shape is plump and beautiful.

It is reported that in order to dwarf the plant shape of Poinsettia, in addition to the above methods, growth dwarfing agents B9 and CCC can also be used to treat leaf or soil collapse to quench thirst, thus shortening the internodes and dwarfing the plant shape.

How to change pots and trim poinsettia?

Poinsettia is suitable for changing pots and soil once a year in early spring. When changing pots, the old soil and rotten soil around the shoulder soil and the original soil lump should be eradicated, and the roots and branches should be trimmed properly. Put the bone fragments as base fertilizer into the bottom of the pot, then fill in the culture soil mixed with 3 parts humus soil, 6 parts sandy loam soil and 1 part cake fertilizer powder, and then plant plants in the pot.

After planting, water it, put it in a cool place, and move it to the sunny place for culture after 10. When the cuttings grow to a certain height in 1 year, the trunk remains about 10 cm high, and the upper part is cut off, and 2-3 lateral branches can grow in that year; If it is a perennial, you can leave 2-3 buds at the base of each lateral branch, and cut off all the upper branches to promote the germination of new branches. If new buds grow after pruning, they should be pulled out at any time. Generally, each medium-sized flowerpot can have 5-7 buds, each bud grows 1 branch, and the top of each branch opens 1 flower. If there are too many buds, thin branches and small flowers, the ornamental value will be affected.