How to Grow Stromanthe sanguinea? Latest Care Guide Explained
Stromanthe sanguinea is also known as red-backed Stromanthe, red-backed prayer plant, red-backed arrowroot, and so on. It is a perennial herbaceous plant of the genus Stromanthe in the family Marantaceae. Its plant form is attractive, its leaf surface is richly multi-colored, and it has strong shade tolerance, so it is often used for indoor potted display. Large varieties can be used to decorate the halls of hotels and shopping malls, while small varieties can accent balconies, living rooms, bedrooms, and so on. Now let us take a look at how to grow Stromanthe sanguinea!
Growth Habits of Stromanthe sanguinea
Stromanthe sanguinea is native to Central America and Brazil, and is cultivated in the southern provinces and regions of China. It likes warm, humid, and shaded environments. The suitable growth temperature is 20-30°C, it needs more water, and it is not drought-tolerant. It is relatively heat-tolerant and slightly cold-tolerant, and can overwinter safely above 5°C. It fears frost, and likes loose, fertile, moist, and well-drained acidic soil.
Propagation Methods of Stromanthe sanguinea
1. Division: Stromanthe sanguinea is generally propagated by division. Propagation is most ideal in spring when the temperature is around 20°C, but as long as the temperature and humidity are suitable, it can also be done year-round. During propagation, use a sharp knife to cut apart root blocks that bear stems and leaves or leaf buds. For small-scale propagation, the cut root blocks with stems, leaves, and leaf buds can be placed directly into clay pots. For large-scale propagation, they should be placed on a seedling bed. When the temperature and humidity do not meet the requirements, cover with plastic film, and be sure to make the temperature inside the film reach 20-28°C and the humidity above 80%.
2. Cuttings: Stromanthe sanguinea is generally propagated by cuttings from tender shoot tips. The cuttings are 10-15 cm long, and depending on leaf size, one third or one half of the leaves are retained. Treat the cuttings with 500 ppm naphthalene acetic acid for 2-3 seconds, or with indoleacetic acid, indolebutyric acid, and ABT rooting powder. After treatment, insert the cuttings into the seedling bed, preferably at a plant-to-row spacing of 5×10 cm. The cuttings usually root in 30-50 days, but the survival rate of cuttings is not as high as that of division propagation, generally around 50%.
How to Grow Stromanthe sanguinea
1. Soil: The soil for growing Stromanthe sanguinea should be fertile, loose, and well-drained. Compacted soil and waterlogging are taboo. Fertile humus soil and porous coarse media are mostly used as the substrate. Generally, use equal amounts of leaf mold and peat soil mixed together, or use pond sludge, peat, and perlite mixed in a 2:3:1 ratio, or use loose leaf mold rich in organic matter plus 1/3 perlite and a small amount of base fertilizer.
2. Watering: Stromanthe sanguinea is not drought-tolerant, so sufficient water must be given during the growing season to keep the potting soil constantly moist, and attention should be paid to spraying water on the leaves. Especially in summer and autumn when the temperature is relatively high and the air is dry, water must also be sprayed frequently on the leaves and surroundings to maintain relatively high air humidity. However, be careful not to let the potting soil become waterlogged, so as not to affect root aeration and cause poor growth or root rot. After late autumn, when the temperature is relatively low, control the amount of watering and just keep the potting soil slightly moist.
3. Temperature: Stromanthe sanguinea is native to tropical and subtropical regions and likes high temperature, high humidity, and a semi-shaded environment. The suitable growth temperature is 20-30°C, the best growth temperature during the day is 18-21°C and at night 16-18°C, and the safe overwintering temperature is 10°C. Therefore, in summer, prevent high-temperature exposure and place it in a cool place. In winter, pay attention to cold protection, and the plant can be moved to a windless, relatively warm indoor place to overwinter.
4. Light: Stromanthe sanguinea avoids direct sunlight and grows better under indirect radiant light or scattered light. In summer, direct sunlight easily causes leaf scorch, so in production it is cultivated under artificially controlled light conditions with a shading net of 75-80% shading. If leaf scorch is found, immediately move it to a place without direct light, or to a location with shading facilities or under tree shade, and cut off the scorched leaves to prevent other pathogenic bacteria from invading through the wounds.
5. Fertilizing: Stromanthe sanguinea should follow the principle of “frequent application in small amounts.” During the peak growing season, apply a mixed fertilizer of peanut bran and compound fertilizer or decomposed compost once every 2 weeks. The nutrient composition of the fertilizer should be mainly nitrogen fertilizer, followed by phosphorus and potassium fertilizers. Appropriately increasing nitrogen fertilizer can make the leaf color more beautiful. However, the concentration of fertilizer should not be too high, otherwise it easily causes leaf scorch and fertilizer damage, and in severe cases may even cause the plant to die. Stop fertilizing during the winter dormant period and when summer is too hot.
6. Pests and diseases: Common diseases of Stromanthe sanguinea mainly include leaf spot and leaf blight. In the early stage of disease, spray with 200-fold Bordeaux mixture 2-3 times every half month, or spray with 65% zineb wettable powder at 600-fold dilution for control. Common pests mainly include scale insects, which are prone to occur when ventilation is poor. During the nymph stage, spray with 50% fenitrothion emulsifiable concentrate at 1000-fold dilution to kill them.