Planting Methods and Key Technical Points for Ruellia simplex
The underground rhizomes of Ruellia simplex spread and grow, forming an interwoven network of horizontal rhizomes. Buds form on these rhizomes and grow upward into aboveground shoots, correspondingly producing adventitious roots and forming new plants. The stems are slightly square in shape, grooved, and reddish-brown. Individual flowers have a short lifespan, opening in the early morning and withering at dusk. The capsules are elongated, initially green and turning brown when mature. After the fruit splits open, the seeds scatter; the seeds are tiny, like powder.
Propagation Methods for Ruellia simplex
Ruellia simplex can be propagated by sowing, cuttings or division, and all three methods can be carried out in spring, summer and autumn.Propagation by Sowing
The capsules can be harvested once they turn from green to grayish-brown. Because the seeds mature in batches and the fruit walls split easily, they should be harvested promptly. Place the harvested seeds in a windless place to dry; after the fruit splits open, gently tap out the seeds, and sow them immediately or store them at room temperature. Choose a soil with good permeability and rich in nutrients as the sowing medium. Rake the seedbed fine, level it, press it firm, and then scrape it smooth again. Before sowing, water the base thoroughly and deeply.
Because the seeds are extremely small, mix them with 1 to 2 times their volume of fine sand or fine soil and sow evenly by broadcasting. After sowing, cover the seedbed with plastic film to prevent water from evaporating too quickly. The optimum temperature for seed germination is 20°C to 25°C. When the soil temperature is too high, increase ventilation; around midday when light is abundant, use a shade net to provide appropriate shading to lower the soil temperature, avoiding loss of seed viability due to excessively high soil temperature. It takes about 5 to 8 days from sowing to emergence. During the seedling stage, pay attention to soil moisture and temperature regulation, strengthen ventilation, increase light, and take care to prevent damping-off disease. When the seedlings have 2 to 3 pairs of true leaves, prick them out and transplant.
Propagation by Cuttings
Use coarse sand, sandy soil or garden soil mixed with sand as the medium. Cut tender shoots from vigorously growing branches as cuttings, 5 to 10 cm long. Make a slanted cut at the base below a node, keep only 2 to 3 leaves at the tip, and remove all the rest. After inserting the cuttings, water them thoroughly and place them in a semi-shaded spot for care. Mist the leaves 1 to 2 times a day to keep the medium moist. At a temperature of 20°C to 30°C, roots form and the plants can be transplanted in about 15 to 20 days.
Propagation by Division
In spring, when temperatures rise and before new buds sprout, carry out division together with repotting or transplanting. Cut the underground rhizomes together with the leaves into several clumps, making sure each clump has 3 to 5 stems, then pot them separately or plant them in the open ground.
Cultivation Techniques
Transplanted seedlings need a certain degree of shade. Large seedlings can be transplanted at any time except winter, and after transplanting they should be kept well watered with appropriate shade. Choose a soil with moderate fertility, loose texture, good drainage and aeration, and rich in humus as the growing medium. Water moderately during the growing period, keeping the soil moist; in the heat of summer, mist the leaves. Farmyard manure and compost are best for fertilizing. To keep the plant's shape attractive, prune or pinch back regularly to control plant height. When plants become old, prune them hard to encourage new shoots to sprout and produce a full, bushy form.
The plant is naturally robust and pests and diseases occur rarely. Root rot occasionally occurs, mostly in hot and humid seasons, often causing the roots to rot and even causing plants to die off in patches. The main control methods are: (1) improve drainage at the planting site; (2) spray with Bordeaux mixture about once every 6 days, for 3 to 5 consecutive sprays; (3) pull out diseased plants and burn them, and disinfect the diseased planting holes with lime solution to prevent spread.