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A Detailed Guide to the Planting Methods and Key Technical Points of the Northern Catalpa

Growing Techniques By Emily Carter 0 views
Trees

The northern catalpa (scientific name: Catalpa speciosa (Barney) Engelm) is a tree in the family Bignoniaceae and the genus Catalpa, reaching up to 10m tall; its crown is umbrella-shaped. The leaves are ovate-cordate to ovate-oblong, with a long acuminate apex and a truncate to shallowly cordate base, bright green above. The terminal panicle bears a few flowers, the bracts are linear, and the lobes are boat-shaped and hairless. The corolla is white, the capsule is cylindrical and black, and the seeds are elliptical. It flowers from May to June and fruits from August to September.


Propagation Methods

Seed selection for sowing: before sowing, the seeds must first be selected; whether the seeds are chosen well or not directly affects whether sowing will succeed.

1. It is best to use seeds collected in the current year. The longer the seeds are stored, the lower their germination rate.

2. Choose seeds that are plump and free of damage or deformities.

3. Choose seeds free of pests and diseases.

Stratification: soak the seeds in warm hot water (at about the temperature of face-washing water) for 12 to 24 hours, until the seeds absorb water and swell. For very common seeds that germinate easily, this step can be skipped.

Sowing: for tiny seeds that are hard to pick up with the hands or other tools, moisten one end of a toothpick with water and stick the seeds one by one onto the surface of the substrate, then cover with substrate 1 cm thick; after that, place the sowing pot into water with a depth of 1/2 to 2/3 of the pot's height, and let the water slowly soak upward (this method is called the "pot immersion method");

Cutting propagation: use semi-lignified cuttings from mature trees, cut them into lengths of about 20cm, with the upper cut about 1cm from the terminal bud, and the lower end cut into a slanted cut near the lower part of the node; the cut must be smooth, not torn, and without peeling bark, and each cutting should carry 2-3 plump buds. Before cutting, soak the base of the cuttings in a 0.1%-0.5% potassium permanganate solution for 30 minutes to disinfect. To promote rooting, the cuttings need some treatment before cutting; ABT No. 2 rooting powder can be used by dissolving 1g of rooting powder in 500ml of 95% alcohol, then adding 500ml of distilled water or cooled boiled water to make 1000ml of a 1000ppm stock solution, then adding more water to dilute it to the required 50ppm concentration for use. Before cutting, dip the base of the branches in it for 2-4 hours, then immediately insert the treated scions into the seedbed. The cutting spacing is 10cm x 10cm; before cutting, first poke holes in the cutting substrate with a small stick, insert the cuttings to a depth of 1/3-1/2 of the cutting length, water thoroughly with a watering can after insertion so the cuttings and substrate are in close contact, then cover with a small plastic arch tunnel and press it firm.


Cultivation Techniques:


Field planting and transplanting can be carried out before bud break in spring, giving a high survival rate. The planting hole can be dug to a size of 1m x 1m x 1m, and base fertilizer should be applied in the planting hole. When planting, place the seedling into the hole, fill in fine soil and tread it firm, then water and mound soil around it. After planting, set up a support, prune and shape the crown appropriately, water thoroughly, then water thoroughly again every 5-7 days, for 3 consecutive times, and then seal the soil to conserve moisture.
During the maintenance growing period, loosen the soil and weed 3-5 times, and irrigate and fertilize in time. Within 2-3 years after planting, weed and cultivate 2-3 times each year, and water promptly during dry seasons. In North China, water thoroughly once with winter irrigation water before the onset of winter each year, and water promptly in spring to promote greening.


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