In most monographs on cold-resistant flowers, pruning is generally not advocated, mainly because cold-resistant flowers grow slowly. Due to the lack of scientific seed selection and management, the growth of traditional cold-resistant flowers is really slow. However, with the development of technology and management, the growth rate of overwintering flowers has been improved to a certain extent by planting in the open air, rational fertilization, insecticidal, bactericidal and antiviral, and selecting varieties with strong disease resistance and vigorous growth, so not only pruning is needed, but also higher requirements are put forward for pruning technology.
First, the purpose of pruning
Before pruning, we must have a clear and correct concept of the purpose and function of pruning, so as to be aware of it, otherwise indiscriminate pruning will often backfire. Anti-winter pruning has two main functions: 1. Trim the appearance of winter flowers to make the tree more neat and beautiful and reach the required shape. 2. Prune old branches and weak branches to promote the germination of new branches, so that the newly germinated branches and leaves grow faster and stronger, thus accelerating the growth rate. The former is easy to understand, while the latter is easy to be ignored. The pruning of cold-resistant flowers must focus on these two points.
The same cold-resistant flowers are used for greening and potted flowers. Different varieties have different ornamental values. Potted flowers are used for family close-up viewing. Relatively speaking, they pay more attention to flower products and leaf color, and have certain requirements on the quantity and quality of flower buds. Moreover, the cultivation period of potted flowers is short, and the growth speed is not high. As a cold-resistant flower for greening, it pays more attention to the overall crown, emphasizes that the leaf color should be dark green, and pays more attention to the growth rate after pruning. These differences determine that there are also great differences in pruning techniques between the two, and growers should pay attention to these differences.
2. Key points of greening and pruning techniques for cold-resistant flowers
1. Trimming time
In principle, the pruning of green trees with cold-resistant flowers is only carried out once a year, and the time should be from the beginning of 10 to the beginning of March the following year before the new buds of cold-resistant flowers germinate. Generally speaking, pruning should be done sooner rather than later, especially when seedlings germinate earlier. It is best to finish pruning before the Spring Festival. If pruning is too late, new buds will sprout and consume some nutrients, and it will take some time to grow new buds after pruning. If the time is really tight, the pruning time of large and medium-sized seedlings can be slightly delayed.
2. Pruning points in different stages
A. Seedling stage: The seedlings just transplanted from the seedling shed (the ground diameter is within 1cm) generally do not diverge. At this time, the height of the main stem and the basic shape of the seedlings should be mainly controlled. It can be picked or pruned as needed: if you plan to cultivate a "tall-stemmed" tree, you should wipe off the top buds of the seedlings, which is also called pinching. If you only want to cultivate low stem type, you can cut off the top branches of 1-2 season, and the pruning position is about 1cm above the inter-season boundary point. After pruning or coring, the height of the main stem is basically fixed. By the middle of March in the spring solar calendar, 3-6 new buds will grow at the top of the plant and gradually form a certain crown pair.
B. Mid-seedling stage: After one year's growth, the seedlings transplanted from the nursery shed will form a certain crown. After that (ground diameter is about 1cm) to ground diameter is about 3cm, which is the middle seedling stage. At present, the overall tree shape is not stable, and it is mainly necessary to control the tree shape: the weak branches that affect the tree shape must be cut off from the base, and the branches that are too high and too long should be shortened to match other branches.
C. Large seedling stage: when the ground diameter of cold-resistant flowers is more than 3cm and the crown width is more than 70 cm, they can be pruned according to the pruning method of large seedlings. The tree type of big seedlings has been basically decided, and pruning is relatively simple. Just trim the long and irregular branches and remove the terminal buds of the shorter branches. If the branches are too short, you can't pick the terminal buds.
3. Pruning methods of different types of cold-resistant flowers
In addition to different pruning methods at different growth stages, varieties with different growth characteristics should also have different pruning methods:
A. Erect growing varieties: Erect growing varieties, such as red, green, colorful and eighteen stones. Generally, it is necessary to trim the height of about 65,438+0/3 by "truncation" to control the plant to grow to a high place, so that more lateral branches will sprout from the branches and the crown will increase year by year without affecting the basic tree shape.
B. Varieties with sexual growth: varieties used for sexual growth, such as five-color anti-winter flowers and Cremo peony. Under normal circumstances, the height should be properly maintained, and the branches on both sides should be shortened to slightly reduce the crown pair.
C for varieties with good natural tree shape, such as red Dan and Xiangyang poplar, the pruning method can be similar to that of large seedlings, and the long and irregular branches can be cut off.
3. Introduce three simple and beautiful types of cold-resistant flowering trees.
Different from azalea, Podocarpus and other flowers and trees suitable for modeling, the leaf density of cold-resistant flowers is limited, so the modeling should not be too complicated. Simple in shape and trimmed in appearance, it is easier to achieve better decorative effect. Here are three simple and beautiful trees:
1. Sphere: It is suitable for varieties with good natural tree shape, small leaves, high leaf density and thick, oblique or straight branches, such as most tea plum varieties, shibashi and Liexiang. When pruning, it is not necessary to emphasize pruning at the dividing point between seasons, just pay attention to cutting off long branches to ensure the overall shape is round and tidy.
2. Tower shape: The tower shape is a tree shape with narrow top and wide bottom, similar to an inverted triangle. Varieties suitable for vertical growth and rapid growth, such as: red green treasure, flower green treasure, Dalian red (Liancheng red) and so on. It is planned to prune cold-resistant flowers into towers. The main stem can be kept higher when seedlings are grown, and the lateral buds can be kept after the terminal buds are knocked out. With the growth of plants, every year,
3. Umbrella: used for varieties with soft branches and sexual growth, such as five-color winter flowers and Cremo peony. , suitable for pruning into an umbrella. The pruning method of umbrella is similar to that of sphere, but the shape is different, so I won't go into details here.
It should be noted that no matter what it is trimmed, it is not trimmed into any shape, but trimmed neatly. For example, a natural tree is not very round, but a little tall, but it is not suitable for pruning into a tower shape, so it can be trimmed into a shape between a sphere and a tower shape according to the actual situation, but it must be trimmed neatly and symmetrically.
Four. Matters needing attention and cooperation in other aspects
1. The pruning of cold-resistant flowers should not only pay attention to the shape after pruning, but also pay attention to the growth rate after pruning, and the pruning intensity should be appropriate. Under normal circumstances, it is advisable to cut off the branches and leaves around 1/3, with more pruning for the vigorous growth and less pruning for the weak growth. Too light and too heavy pruning intensity are not conducive to growth.
2. Pruning cold-resistant flowers should follow the trend as much as possible. Different varieties of cold-resistant flowers have different natural growth characteristics, and there are also great differences among different individuals of the same variety. This requires growers to know how to use different shapes according to the growth characteristics of different varieties and individuals. For example, the varieties with slightly soft branches should be trimmed into umbrellas, and the varieties growing vertically should be trimmed into towers.
3. No matter what shape it is trimmed, the side branches below the bifurcation point of the main stem must be cut off, as well as the diseased branches and weak branches that consume nutrition and affect ventilation above the bifurcation point.
4. Coordination of fertilization: In order to make the cold-resistant flowers grow quickly after pruning, it is best to apply slightly low concentration liquid fertilizer (appropriately increase the proportion of phosphate fertilizer) before pruning 1 month to make the root system more developed. After pruning 10-20 days, apply liquid fertilizer to promote germination (appropriately increase the proportion of nitrogen fertilizer).