How to care for flowers in autumn? Remember these three key care points

After the beginning of autumn, trees enter a peak growth period and have a relatively large demand for water and fertilizer, so reasonable fertilization should be carried out. When fertilizing, note the following: First, the amount should be appropriate. When fertilizing trees in autumn, follow the principle of applying less; the amount of fertilizer should not be too large, as too much fertilizer can easily cause excessive vegetative growth in trees or even death from fertilizer burn. Second, the fertilizer applied should target the right need.

Autumn fertilizer should be mainly phosphorus and potassium fertilizer, with nitrogen fertilizer applied cautiously, because applying nitrogen fertilizer at this time will cause excessive vegetative growth in trees, reduce the degree of lignification, and make them prone to frost damage or wind damage in winter. Phosphorus and potassium fertilizer, however, can promptly supply the nutrients needed for tree growth, help increase the degree of lignification, and help trees overwinter safely. Third, timing should be appropriate. Autumn fertilization should be early, applied when trees are in their vigorous growth period and most need fertilizer. Generally speaking, fertilization should stop before early September; fertilizing too late can easily cause excessive vegetative growth in trees.

In addition, in late autumn, one application of farmyard manure can be made together with watering the freeze-proof water. This fertilization can be somewhat larger in amount. When applying, it can be applied shallowly, or directly scattered on the soil surface, which helps trees overwinter safely. Since autumn is a peak period for root growth, for trees newly planted in spring, some phosphorus and potassium fertilizer can be applied together with base fertilizer to increase accumulation in the tree body and raise the cell sap concentration, thereby enhancing the trees' overwintering ability and laying a foundation for growth and development the following year. In addition, increasing the application of organic fertilizer can improve soil porosity, make the soil loose, help the soil retain snow and preserve moisture, prevent soil drought in winter and spring, raise soil temperature, and reduce frost damage in the root zone.

The autumn climate is dry, and trees also have a relatively large demand for water. Especially for trees planted in the current year, water deficiency must not occur. In early autumn, temperatures are still high, and tree transpiration is relatively large, so appropriate watering should be given to prevent autumn drought. After each watering, soil should also be loosened in time to preserve moisture. After late September, watering should be strictly controlled to prevent autumn growth in trees; it is best if the trees do not wilt. If the weather is too dry, a small amount of water can also be given to keep the trees in normal vital condition.

Pruning management

Many trees, especially some flowering shrubs, differentiate flower buds precisely in early autumn. If pruning is done reasonably at this time, it not only benefits flower bud differentiation in trees, but can also increase the degree of lignification of new shoots, helping trees overwinter safely. In early autumn, for flowering shrubs that differentiate flower buds at this time, such as flowering almond (Prunus triloba) and ornamental peach, measures such as twisting shoots can be taken to control the vegetative growth of their branches and save nutrients for flower bud differentiation. The new shoots of other trees can be appropriately pinched; pinched branches become thicker and stronger, have a higher degree of lignification, and have stronger cold resistance.

Before mid-autumn, pruning hedge plants such as big-leaf boxwood (Euonymus japonicus), golden-leaf privet (Ligustrum sinense 'Variegatum'), and purple-leaf barberry (Berberis thunbergii var. atropurpurea) not only benefits ornamental value but also controls vegetative growth, and their wounds can heal before winter, which is very beneficial to both the ornamental value and growth of the hedge. In addition, in autumn, some overly dense branches, parallel branches, thin and weak branches, and pest- and disease-damaged branches of trees can also be pruned, which helps ventilation and light penetration through the plant canopy and has a positive effect on preventing and controlling pests and diseases. For flowering shrubs that bloom in autumn, such as crape myrtle, Chinese rose, and rose of Sharon, spent flowers should also be cut off promptly after each bloom to prevent fruit set, so as to avoid excessive nutrient consumption and affected growth.

Pest and disease control

Autumn is a period of high incidence of pests and diseases. For diseases, timely control should be carried out, and it should be thorough to prevent rebound. In late autumn, fallen leaves in green areas should be cleaned up thoroughly; doing so can effectively reduce the occurrence of pests and diseases the following year.

For some insect pests, such as the fall webworm and other leaf-eating pests, autumn is precisely their peak damage period, when they feed on large amounts of leaves and form cocoons to overwinter. Therefore, doing a good job of autumn pest and disease control, reducing the base number of insects the following year, ensuring normal leaf growth of broadleaf tree species, and ensuring plump winter buds are extremely important. For pests at the late growth stage or egg-laying stage in autumn, while killing adults and nymphs, efforts should also be made to eliminate eggs. For trunk-boring pests such as longhorn beetles, multiple measures should be taken for integrated control.

Autumn storage

After nursery stock is dug up in autumn, if it cannot be planted in time, it should be stored to prevent the stock from losing water and drying out in the wind. The following points should be carried out promptly:

1. Burying with fine sand is best done by trench storage. The trench depth is 50 cm, and the length and width are determined by the quantity of nursery stock. After the trench is dug, place the nursery stock bundle by bundle into the bottom of the trench with roots facing down and tips facing up. The bundles should not be packed too tightly, to prevent root rot. Fill with river sand that has passed through a coarse sieve; while filling with sand, move the nursery stock so that sand fills the spaces between bundles and between plants.

2. Appropriate watering. Pour water forcefully above the nursery stock so that the sand is washed in as much as possible into the spaces between bundles and between plants. Water thoroughly in one go, and by all means avoid repeating, to prevent waterlogging damage and root rot. After watering, cover the stock with 10 cm of river sand.

3. According to local conditions, cover with grass to protect against cold. When temperatures rise the following year, remove the cold-protection grass in time, so as to avoid sprouting and root burning due to excessively high temperatures.