When will crape myrtle be planted?

The planting time of Lagerstroemia indica is 1, and the transplanting time is from autumn defoliation to spring bud germination. Small seedlings can be transplanted with bare roots, and big seedlings need soil balls to transplant. When planting, compost should be applied and irrigated twice to make it permeable, and then timely irrigation, loosening soil and weeding should be carried out. Lagerstroemia indica can be planted in spring with bare roots. Keep the root system intact when planting seedlings.

2. Planting place The planting place should be sunny, moist and fertile loam with good drainage.

3. Water and fertilizer management Apply sufficient base fertilizer before planting. Fertilizers can be decomposed human excrement, manure, manure and compost. In the first three years after planting, 65,438+00 ~ 65,438+05 kg (mainly organic fertilizers such as compost and cake fertilizer) should be applied to the roots every winter or spring before germination, and some compound fertilizers can also be applied as appropriate. The surviving Lagerstroemia indica is watered 1 time every spring, 3 ~ 4 times later and 1 ~ 2 times in flowering period. In North China, water with frozen water once before freezing, and pay attention to drainage after rain.

4. Pruning planted crape myrtle should pay attention to pruning. When planting larger Lagerstroemia indica, it should be pruned again before planting, and the trunk with uniform height can be set according to the cultivation needs, and all the upper crowns will be cut off to make the newly grown crowns grow vigorously and neatly. During the growth of young Lagerstroemia indica, the lateral buds at the lower part of the stem should be pulled out at any time, so that the terminal buds and upper branches can get more nutrition, grow healthily and form a complete crown as soon as possible. During the growing season, the residual flowers and branches should be cut off in time to promote the development of new branches to prolong the flowering period, and the crape myrtle inflorescence opens at the top of the new branches. Prune long branches, twigs, diseased branches and dead branches after defoliation.

Eliminate pests and diseases

Insect pests are mainly caused by aphids, crape myrtle, giant salamander and sooty blotch, which should be prevented in time.

Spray 800 ~ 1000 times 1.2% Kuyan EC, 3000 times 50% pirimicarb, 2500 ~ 3000 times 2.5% triadimefon, or 3000 ~ 4000 times 6% imidacloprid on aphids. Be safe when spraying.

For Lagerstroemia indica, when no wax is formed or a wax layer is just formed within 7 days after the hatching period of nymphs, the branches and leaves are sprayed with 1500-2000 times of 40% quick-killing emulsifiable concentrate, 2000 times of 6% imidacloprid soluble concentrate and 2500 times of pyrethroid pesticides. The above three chemicals are used alternately and sprayed once every 7 ~ 10 day for 2 ~ 3 times in a row, which can achieve good results. The key to spraying is to seize the opportunity (nymph stage), once the shell is formed, spraying is difficult to be effective.

For the giant salamander, the pouch of the marsupial moth on the tree can be seen after defoliation in winter, which is artificially removed; Trapping and killing adults with frequency vibration insecticidal lamp; Moth larvae are sensitive to trichlorfon, and good results can be achieved by using 90% trichlorfon crystal 1000 to 1500 times. You can also use 3,500 ~ 4,000 times of 2.5% deltamethrin EC, or 1 0,000 ~ 1 0,500 times of 50% phoxim EC and10,500 times of 20% pyrethroid EC to spray evenly and thoughtfully.

For sooty blotch, it is mainly caused by the secretion of sucking pests such as aphids and scale insects, which is the key to control.