A Detailed Guide to Plumbago auriculata Planting Methods and Care Tips
Plumbago auriculata (Latin scientific name: Ceratostigma plumbaginoides), also known as shanhuichai or false indigo (Henan), jiaozhuhua, etc., is a perennial upright herbaceous plant belonging to the Plumbaginaceae family and the genus Ceratostigma. Plumbago auriculata grows vigorously, is heat-tolerant, relatively tolerant of high temperature and high humidity, has few pests and diseases, is simple to manage, and has a long ornamental period.
Propagation Methods
Seeds number 85 per gram. It can be propagated by sowing, and also by cuttings or division. Cuttings and division are mostly used; cuttings can be done in spring, early summer or late summer, and are generally carried out in May to June. The suitable temperature for rooting is 20°C to 25°C, and rooting occurs about 20 to 28 days after cuttings are inserted.
Seedling Cultivation
Plug tray specifications: 288, 200, 128 or 72-cell plug trays.
Medium selection: a lightweight medium free of pests and diseases with good drainage, which can be made by mixing peat and vermiculite in a certain proportion, pH 5.8 to 6.2, EC value less than 0.75 mS/cm. After sowing, cover with coarse vermiculite.
Temperature: the optimum temperature for germination is 22°C to 23°C, and the optimum temperature for seedling growth is 18°C to 21°C. Germination takes 4 to 6 days.
Light: light is not required during the germination stage, but timely supplemental lighting after germination can effectively shorten the growing cycle.
Water: keep the medium moist during seedling cultivation to avoid seedling wilting.
Fertilizer: after the cotyledons emerge, begin applying 100 ppm fertilizer 1 to 2 times per week.
Later stage: increase the nitrogen fertilizer concentration to 150 to 175 ppm; fertilizers with an N-P-K ratio of 13-2-13 or 14-0-14 can be applied alternately with 20-10-20 fertilizer.
Growth regulators: not needed during the plug seedling stage. Plug seedling cultivation takes 6 to 8N (288-cell plug tray).
Potted Flower Management
Medium: pH 5.5 to 6.0. The planting depth should be such that the potting soil just covers the top of the plug seedling root ball. A small amount of fertilizer can be added to the medium.
Temperature: the optimum temperature for growth is 17°C to 26°C, and it can withstand up to 35°C. Strong light and relatively high temperatures favor branching.
Fertilizer: apply a complete-element compound fertilizer at 200 to 300 ppm at least once a week.
Water: keep the medium surface dry in daily care. When watering, make sure to water thoroughly to prevent the EC value from becoming too high and the soil from becoming salinized.
Management: during the process of growing to a mature seedling, pinching is needed 2 to 3 times; pinching can delay the flowering period by about 2 weeks.
Pest and Disease Control
The main damage is from mites, which cause the leaves to curl inward; applying acaricides can control them. During the seedling stage, after true leaves appear, spray the foliage with 0.01% peptide nitrogen, and growth will be faster; after the seedlings mature, spray with 0.1% peptide nitrogen once a week. For daily water management, water thoroughly when watering, and keep the soil moist or slightly dry, never too wet. The roots are susceptible to root-knot nematodes, so attention should be paid to disinfecting the soil before use; during the disease period, a diluted solution of 80% Z. bromochloropropane emulsifiable concentrate can be sprayed on the soil surface. For insect pests there are scale insects, which can be controlled by spraying with a 1000-fold dilution of 25% phosmet emulsifiable concentrate. Time from sowing to flowering: 14 to 18 weeks in a 10 cm pot.