Key points of seedling-raising techniques for Japanese white pine, rhododendron and other seedlings

Seedling raising of Japanese white pine, rhododendron, etc.

For Japanese white pine, in autumn mix the seeds with coarse sand at 1:5, put the mixture in a flower pot and bury it outdoors in a sunny, well-drained spot, and sow around Qingming Festival. Broadcast sow on the seedbed, cover with 1 cm of sandy loam, and generally the seedlings can emerge completely in two months. If the quantity of seeds is very small, soak the seeds in warm water in spring; after 2-3 days, carefully break open the outer seed coat, sow in pots at 25°C, and seedlings can emerge in about 10 days.

When propagating wild rhododendrons or breeding new hybrid cultivars, rhododendrons are often raised from seed by sowing. Rhododendron seeds are tiny, so sow in pots in autumn or spring. Use a shallow pot with a 2 cm thick layer of small pebbles at the bottom, and on top use a growing medium of peat soil and fine sand mixed evenly at 2:1; fill and press level to 2 cm below the pot rim, place the seeds on paper, gently shake to broadcast sow them on the surface, then sift a 2 mm thick layer of fine soil over the seeds. Soak the pot to keep it moist, place the flower pot inside a greenhouse film cover, and at 20-25°C seedlings can emerge in 1 month. When the seedlings are about 1 cm tall, thin out buds and transplant sparsely into a hotbed or flower pot, and with careful cultivation the plant height can reach 5-10 cm in the same year.

Jojoba, also known as jojoba and Simmondsia chinensis, is native to the western United States and is a woody oil plant of the family Simmondsiaceae. The seeds are brown, the size and shape of a peanut kernel, with a 1000-grain weight of about 500 grams. Sow in spring and germinate at 25-27°C, changing the water every day to prevent the seed coat from molding; sow after the seeds crack open, and seedlings emerge in about 10 days. Sow in a hotbed and then transplant sparsely, and the plant height can reach 30 cm in the same year.

Swida wilsoniana, also known as dog-bone wood, is a woody oil plant of the family Cornaceae; the same genus also includes Cornus, red osier dogwood, Cornus paucinervis, and Cornus officinalis. The seed coat is thick and hard; before sowing, remove the oily substance on the outside of the seed coat, generally by mixing the seeds with coarse sand and rubbing and washing them. For spring sowing, 20-30 days before sowing, soak 2-3 times a day in 50-60°C warm water for 30 minutes each time, then scoop them onto a wet cloth to germinate in a greenhouse; when half of the seeds have cracked open, they can be sown, and seedlings emerge about 40 days after sowing, with the plant height reaching 30-50 cm in the same year.