How to Plant Clover? Detailed Guide to Planting Time, Care Methods and Uses
Clover is a perennial herbaceous plant of the genus Trifolium in the legume family Fabaceae. It is the most widely distributed of the legume forages and also the legume forage best suited to grazing. It originated in Europe, Asia and Africa, and is currently distributed in temperate and subtropical regions. In China it is cultivated in both warm temperate and subtropical regions. It is not only a high-quality forage for herbivorous livestock and poultry, but also an excellent ornamental lawn commonly used in modern landscaping.
Clover has strong cold resistance. When the temperature drops to 0°C, some old leaves turn yellow and withered, and the small leaves on the main root press close to the ground and stop growing, but they remain green. Therefore, the green period is very long. It is not demanding about soil and can adapt to various soil types, growing well on slightly acidic soil. It prefers warm, sunny conditions with good drainage. Under drought conditions it grows slowly, and some plants die back during the hot season. It tolerates pruning and trampling, and has strong regeneration ability; new small leaves can grow within 10 days after pruning. After heavy trampling or rolling, it can recover in 3 to 5 days. Under strong shade it tends to grow spindly, resulting in poor growth. It has strong resistance to harmful gas pollution and to pests and diseases.
Clover Planting Time
Before sowing, a seed germination test should be carried out to determine the germination rate and germination vigor of the seeds. The germination rate of clover seeds is 75% to 85%, and their germination vigor is very strong; 2 to 3 d after sowing all seeds can germinate, and 4 to 5 d all can emerge. Before sowing, seeds can be inoculated with clover rhizobia. After inoculation with rhizobia, clover grows vigorously and its nitrogen fixation is enhanced. The inoculation method is to take clover root nodules, crush them, dilute with water and mix with the seeds, using just enough to wet the seeds thoroughly. Commercial clover rhizobia inoculant can also be used for seed treatment.
Clover can be sown in spring or autumn, in late March in spring and in mid-September in autumn. In the south, autumn sowing is the main method, while in the north, spring sowing is the main method. It can also be sown in summer, but after sowing the topsoil must be kept moist or covered with mulch for shade. The sowing rate for establishing a clover lawn is suitably 8 to 10 g/sq m. Each gram of clover contains 1,400 to 2,000 seeds; in theory, 1 seed per square centimeter of soil is enough to meet the needs of lawn formation. The actual sowing rate is greater than the theoretical sowing rate.
When sowing, divide the seeds equally according to the plot area and the determined sowing rate, mix the seeds evenly with dry soil or fine river sand, and broadcast by hand. For large-area lawn establishment, a cyclone seeder can be used for broadcasting. The sowing depth of clover is 1 to 1.5 cm. After the seeds are broadcast onto the lawn bed, a lawn rake can be used to rake the seeds into the soil, or fertile soil or substrate can be used to cover them by 1 cm.
Clover Care Methods
Clover grows slowly at the seedling stage, and management before the lawn is established is crucial. After the seeds are sown onto the lawn bed, if a sprinkler irrigation system has been installed in advance, sprinkler irrigation can be used. If there is no sprinkler irrigation system, a homemade sprinkler head can be used for manual spraying irrigation. Spray in the morning or evening every day, always keeping the surface of the lawn bed moist until emergence. After emergence, the number of waterings can be reduced, but careful management is still required. Seedling management lasts about 30 to 50 d. During this period, in addition to watering to keep the lawn bed moist, weeds must be removed at any time, mainly by hand pulling, to prevent weed damage. Under normal circumstances, the cotyledons emerge from the soil 4 to 5 d after sowing. The first true leaf grows 8 to 10 d later, and it is a simple leaf. The second true leaf grows 13 to 15 d later, and it is a palmately trifoliolate compound leaf. After 20 d the third true leaf grows, and the seedlings reach about 5 cm in height. After 30 to 50 d they can cover the ground and form a lawn. For lawn beds sown in summer, rice straw or wheat straw should be used as cover, which can both avoid high-temperature damage and keep the lawn bed moist. When the true leaves have grown and cover the ground, remove the cover on a cloudy day or in the evening.
After the clover lawn is established, because of its strong invasiveness, intertillage and weeding are not needed. Because nitrogen-fixing rhizobia can absorb nitrogen from the air and convert it into a form usable by plants, fertilization should focus on phosphorus and potassium fertilizers, with no or little nitrogen fertilizer. During the peak growing season and at overwintering, sufficient water must be supplied to ensure vigorous growth and safe overwintering. Before midsummer, one mowing can be carried out and sufficient water applied to keep the plants green. Before overwintering, mow once more and apply sufficient winter water. In this way, when the lawn turns green again the following year, there will be no yellow and withered branches and leaves on the lawn surface. Clover has strong pollution resistance and pest and disease resistance, and has fewer pests and diseases. When pests such as leafhoppers, weevils and cutworms are found, they can be killed by spraying dimethoate, dichlorvos and similar agents.
In addition to direct sowing to establish a lawn, clover can also be established by substrate seedling raising and division propagation.
Chemical weeding during this period can effectively reduce the amount of weeds occurring after lawn sowing. Generally, when preparing the land, perennial rhizomatous weeds must be picked out of the plot, and then light watering is carried out to promote the germination of weed seeds. When the weeds have basically all emerged, glyphosate or paraquat is used to kill them. Although glyphosate and paraquat are non-selective herbicides, they become passivated and ineffective about eight hours after contact with the soil, and will not affect the germination of clover seeds sown a few days later.
This method is suitable for establishing a lawn in summer or when weeds are difficult to remove. The specific method is to choose an idle site; bare land, brick ground, concrete ground and so on are all acceptable. Spread a 3 to 5 cm thick layer of substrate evenly on the site; the substrate can be river sand, peat soil, vermiculite and similar materials. Broadcast the clover seeds into the substrate, still at a sowing depth of 1 to 1.5 cm, and use manual spraying for irrigation to keep the substrate moist. After 20 to 30 d of management, the clover can become seedlings. At this time, transport the clover together with the substrate to the lawn establishment site, and on the prepared lawn bed, plant them by division at a row and plant spacing of 20 cm × 20 cm. After planting, strengthen water and fertilizer management, and after about 20 d they can cover the ground and form a lawn.
For grassland that has grown for more than 2 years, the soil layer is compacted and poor in aeration. Before turning green in spring and autumn and before regrowth after grazing and mowing, harrowing and loosening the soil should be carried out, and fertilization should be applied together with soil loosening, applying 20 to 25 kg of superphosphate per 667 sq m to benefit the growth and development of new buds and new roots. Clover has relatively high requirements for soil moisture. Where irrigation conditions exist, irrigate when the soil is dry or together with topdressing.
Clover Uses
In towns and cities, clover is mainly planted for lawn establishment and for greening and beautifying the environment. It can be mixed and planted with plants such as red fescue, bluegrass, redtop and perennial ryegrass; the mixing ratio is determined according to the color tone required, and generally the proportion of clover is mostly between 20% and 50%. For use in soil and water conservation, fine land preparation is also needed at sowing, and sowing should be done by taking advantage of soil moisture after rain; mixed sowing with forages such as timothy and perennial ryegrass gives better results.
1. Improve the soil, increase soil organic matter, and help build up soil fertility. Clover has a large growth volume and high biological yield, generally yielding about 3,000 kg per mu. When it dies naturally in summer or is mowed and turned into the soil, it plays a significant role in improving the soil fertility of newly built orchards and increasing the soil organic matter of old orchards.
2. Soil cover, lowering summer soil temperature. When the root zone soil temperature of fruit trees reaches 35°C, their absorption capacity declines markedly. When clover grows well, it can lower the ground temperature by about 6 to 8°C in summer, which is beneficial to the normal growth of fruit tree roots.
3. Drought resistance and moisture conservation, stabilizing orchard air humidity. This is beneficial to fruit tree growth in summer, effectively promoting normal fruit enlargement, reducing fruit cracking and fruit drop, and achieving high quality and high yield of fruit trees.
4. Prevent washing away and maintain good soil structure. Because of the good covering effect of clover, it can effectively avoid the washing and deposition effects of rainwater on the soil, maintain good soil structure, and benefit the activity of soil microorganisms and the metabolism of fruit tree roots; it also benefits the decomposition of various fertilizers and the degradation of harmful substances.