How to Grow Irises? Detailed Guide to Cultivation Methods and Precautions
Irises are surely familiar to many people; they are a fairly common flower variety in daily life. Because of their high ornamental value, irises are deeply loved by people and widely cultivated, and their main ornamental feature lies in their flowers, which are commonly seen in purple and blue. But before growing them, what everyone surely cares about most is their cultivation methods!
How to Grow Irises
1. Soil temperature is quite important; keep it at a minimum of 5-8°C, and do not let it exceed 20°C at the highest. The soil temperature affects the emergence of iris seedlings. The optimal temperature is between 16-18°C.
2. When growing irises in a greenhouse, the optimal temperature is 15°C. For about the first three weeks, keep the greenhouse temperature at 18°C. At 13°C, or within the low temperatures irises can tolerate, their growing period will be extended and the weight of the irises will increase, but the flowers are prone to wilting.
3. In autumn, ensure sufficient light in the greenhouse, and at the same time keep the greenhouse temperature somewhat lower to prevent the flowers from wilting. It is best at 10-13°C. During the plant growth stage, consider pruning the leaves.
4. The average daytime and nighttime temperature should be 20-23°C, with the low temperature kept within the range irises can tolerate. High temperatures and little sunlight are important causes of flower wilting.
Iris Cultivation Methods and Precautions
I. Cultivation Methods:
1. Soil: Irises grow poorly in acidic soil, so when growing irises you should choose humus-rich clay loam, or an alkaline soil mixed with lime. Before planting, the soil should be thoroughly plowed, and well-rotted compost plus a small amount of bone meal, plant ash, etc. should be applied as a base fertilizer. In addition, irises should not be planted too deep, and the rhizomes should be pressed firm.
2. Watering: After planting irises, water them thoroughly once, and afterward water according to the dryness and moisture of the soil; generally it is best to keep the soil slightly dry. Do not let the soil become waterlogged or remain overly wet for a long time, so as to avoid root rot or disease. To keep the plant looking attractive, you can wash the leaves of the plant.
3. Fertilizing: From spring sprouting and growth until before flowering, irises should be given 1-2 applications of well-rotted dilute cake fertilizer water or compound flower fertilizer; after the flowers fade, it is best to apply 1 more application of liquid fertilizer.
II. Precautions:
Iris growth takes eight to twelve weeks. During this process, after the soil has been treated, there is no need to worry about weeding while the irises are growing. After irises are planted, herbicides are generally used to remove weeds. But be careful not to cause harm to the irises.
What to Do If Iris Leaves Turn Yellow
1. Excessive sunlight exposure. Solution: When the sunlight is strong, provide shade. In addition, when growing irises outdoors, you can spray appropriately at noon to increase air humidity and lower the temperature.
2. Overwatering. Solution: Water once every 7 days during the growth period; as the temperature drops, the amount of water should gradually decrease, and it is enough for the potting soil to be slightly dry.
3. Excessive fertilizer. Solution: Use some base fertilizer before cultivation, apply fertilizer once every autumn, and increase it appropriately during the growth period.
Common Iris Diseases and Their Control
1. Rot disease. Symptoms mainly harm the bulbs, causing the bulbs to turn black or even blue-brown, with spore masses covering the surface. Usually the aboveground parts show no abnormality or show it very late, seriously affecting the growth of the underground rhizomes.
Control method: Keep air humidity below 70%, and maintain air circulation during storage.
2. Crown rot. Symptoms: Infected plants generally develop normally in the early stage, then afterward wilt, lodge, and the bulbs become completely soft, with the plants covered in white fabric-like growth.
Control method: Disinfect the soil and bulbs before planting to thoroughly eliminate the source of infection. After discovering diseased plants, remove them promptly, and clean the surrounding soil thoroughly to avoid secondary infection.
3. Gray mold. Symptoms: Plants infected with this disease have their growth hindered, the sheath leaves are affected by wet rot, and from the ground portion upward they are covered with a gray spore net. Although the leaf tips do not turn yellow, the plants still lodge.
Control method: When planting, the bulbs should not be too dense, and ensure there are no weeds in the soil during the growth period. Keep soil humidity at around 80%, and keep the plants dry. Water as much as possible in the morning or forenoon, and let the plants get sunlight promptly after watering. When spots appear on the plants, spray fungicide promptly.
When growing irises, be sure to pay attention to the soil ratio and temperature control, and then also strengthen the management of fertilizer and water; only in this way can their growth be ensured. If irises show yellowing leaves, first find out the cause, then solve it thoroughly at the root.