Detailed Explanation of Full-Sun Nursery Technique for Hardwood Cuttings of Dawn Redwood

Dawn redwood cutting propagation mostly uses shading methods. This requires shade netting and daily uncovering and covering of the shade shed. Experimental research on full-sun nursery of dawn redwood hardwood cuttings shows that with appropriate methods, the survival rate generally reaches over 90%. The method is described below:

Fine land preparation The nursery site needs flat terrain, deep soil, and convenient drainage and irrigation. Generally, the land is deep-plowed before winter, and after thawing the soil is broken up fine and leveled flat, with 10 to 15 kg of phosphate fertilizer applied per mu, bed width 1.5 to 1.7 m, bed length depending on the number of cuttings, row spacing 12 to 15 cm, plant spacing 3 cm, with 17,000 cuttings planted per mu.

Cutting collection and storage Dawn redwood cuttings taken from current-year lignified branches on the side branches of 2- to 3-year-old mother trees have a relatively high survival rate. As the age of the mother tree increases, the survival rate of hardwood cuttings decreases.

1. Collection time: Late December to early February each year is best. Select plump current-year branches with terminal buds, preferably 15 to 18 cm in length.

2. Cutting storage: Bundle about 100 cuttings per bundle, level the bottoms, and store them in moist yellow sand at a thickness of about 5 cm. The sand moisture is best when it forms a ball in the hand and breaks apart when released. After sand storage, cover with plastic film on top to retain moisture and prevent water loss. During sand storage, frequently check the moisture conditions and ventilate the plastic film.

Cutting essentials The time for dawn redwood hardwood cuttings is from mid-to-late March to early April. After preparing the bed surface, insert the cuttings while watering, mainly using the slurry-insertion method. Insert 2/3 of the cutting into the soil and leave 1/3 exposed above ground. After finishing one bed, water thoroughly. One week later, because of the slurry insertion, the soil between rows in the seedbed may become compacted or crack, so timely shallow hoeing and loosening of the soil 1 to 2 times is needed, then cover between the cutting rows with rice straw, preferably without exposing the bed soil, using about 300 kg of straw per mu, to retain moisture and increase soil temperature, promoting leafing and rooting.

Water and fertilizer management The false survival period of dawn redwood cuttings is relatively long (nearly two months), and from cutting to rooting generally takes 2 to 3 months. At this time, light is strong, temperature is high, and evaporation is large, so managing water well is the key to the success of full-sun nursery. According to the characteristics of dawn redwood, adopt the method of "frequent watering." In April and May during the seedling sprouting period, water must be applied once; in May and June during the rooting period, water generally once every 10 days; in July and August during the peak growth period, apply fertilizer water once a week; after late August, reduce the frequency of watering. In late July, when seedlings reach about 20 cm in height, carry out the first application of fertilizer with water, using 10 kg of ammonium bicarbonate per mu plus 1,800-fold trichlorfon aqueous solution or carbofuran applied at the same time to control underground pests. After that, apply fertilizer once every 10 to 15 days, and stop fertilizing in mid-October.