Detailed Explanation of Key Techniques for Planting Landscape Nursery Stock
Landscape nursery stock occupies an important position in landscape greening; once planted well, it can enhance the urban environment. So what are the techniques for planting landscape nursery stock?
1. Site selection and land preparation
Landscape nursery stock is suitable for planting in slightly acidic soil that is deep and loose, moist and fertile, and well-drained; at the same time, irrigation and drainage conditions must be good and roads must be accessible, allowing tractors or trucks to pass, so as to facilitate the transport of nursery stock and materials. After selecting the site, the soil should be deeply plowed, and it is advisable to apply 500 jin of cake fertilizer per mu or 6000-7000 jin of barnyard manure plus 50 jin of phosphate fertilizer. Then dig a seedbed 110 cm wide, with a walkway 30 cm wide and 25 cm deep, and dig the surrounding ditch and waist ditch (50 cm wide and 50 cm deep) so that they connect with the drainage canal.
2. Lifting seedlings and planting
(1) Time for lifting seedlings: from October to the end of March of the following year.
(2) Transport: for nursery stock with root balls, when the root ball is less than 30 cm, it can be stacked in two layers; when the root ball is larger, the root ball should be supported steadily and arranged tightly one by one. When loading and transporting shrub seedlings and seedlings with root balls and a height below 1.5 m, they can be loaded upright in the truck, but no one may stand on the root balls and no heavy objects may be placed on them.
(3) Planting density: the row and plant spacing for the first fixed planting is generally 70 cm * 80 cm (1100 plants/mu), planted in a plum-blossom or triangular pattern. The row and plant spacing for the second planting is generally 70 cm * 40 cm, and in the second year the middle 1 plant is transplanted to expand the area to 1.5 or 3 times.
(4) Planting: generally bare-root seedlings are planted. For tree species prone to producing adventitious roots at the root crown, or when the planting site is well-drained sandy loam, they may all be planted somewhat deeper, with the root crown (the original soil mark) 5-10 cm below the ground. Seedlings with root balls, shrubs, or planting sites with poorly drained clay soil must not be planted deep; the root crown should be slightly 2-3 cm below the ground or level with the ground. For evergreen conifers and fleshy-rooted plants, the depth to which the root ball enters the soil should not exceed 3/5 of the root ball thickness. When planting in areas with heavy clay and poor drainage, the top of the root ball should be at least outside the topsoil layer, and after planting, soil should be filled around the exposed root ball to form a soil mound.
3. Field management
(1) Management after planting and before survival: after the saplings are planted, soil should be built around the tree hole into a soil ring 15-20 cm high, whose inner diameter should be larger than the diameter of the tree hole; the ring should be built solid and its bottom should be flat, used to hold back water when watering. The period after planting until survival (about 2 weeks) is the key period, and attention should be paid to water management; water thoroughly at planting to settle the roots, water once again after four days, and thereafter water once every ten days, the so-called watering “three waters” (except on rainy days). On cloudy and rainy days, clear the ditches to drain waterlogging, and pay attention to hilling up soil, straightening, and compacting.
(2) Water and fertilizer management: after planting, the field soil should be kept moist to facilitate the survival and growth of the nursery stock. Generally, after about 10-15 days of clear weather, drought protection is needed once, and flood irrigation (which must not cover the surface of the seedbed), sprinkler irrigation, etc. may be used. On cloudy and rainy days, pay attention to clearing the ditches to drain waterlogging. Irrigation water must be clean; polluted water sources must be avoided. Fertilization can begin after the nursery stock survives planting and starts to grow. Generally, during the growing period (April to August), fertilizer may be applied once every 10-15 days, with 5 kg of urea per mu each time; after the beginning of autumn in mid-August, apply 5 kg of compound fertilizer per mu every 10-15 days; in mid-to-late September, apply 50 kg of phosphate fertilizer per mu once. After winter begins, open ditches between the rows and apply farmyard manure (barnyard manure) at 3000 jin/mu, which is extremely beneficial to the growth of the nursery stock the following year. During the growing period, foliar fertilizer may be sprayed multiple times (special-purpose foliar fertilizer, 0.2-0.3% potassium dihydrogen phosphate, and urea all have good effects). Fertilizer should be scattered into the surface soil between the rows (to prevent injury to the seedlings), followed immediately by loosening the soil and weeding.
(3) Pest and disease control: observe more and control pests and diseases. From April to June, control cutworms; in the evening, spray a 1000-fold solution of acephate + deltamethrin. In September, pay attention to controlling underground pests such as mole crickets and white grubs, which can be trapped and killed with poisoned bait and blacklight lamps. During the peak growing period, pay attention to controlling foliar pests and diseases. Field soil that is too wet is prone to root rot and stem rot; the main measures are to reduce humidity, dry the field, and spray fungicide (Dike).
(4) Loosening soil and weeding: weeding should be done “early, while small, and completely”; in the first year, strictly prevent weeds from ruining the seedlings, and combine loosening the soil to improve soil structure, weed, and promote the growth of the nursery stock; generally loosen the soil 1-2 times per month to a depth of 3-5 cm. If rice straw, crop stalks, or thatch are used to cover the seedbed, it is extremely beneficial for controlling weeds and keeping the soil moist and loose.