How to Grow Cilantro (Coriander) in Summer at 35°C High Temperatures
In summer, it is advisable to choose heat-tolerant varieties that bolt late and grow quickly. Choose soil that is fairly fertile, with good water and nutrient retention, can be watered in drought and drained in waterlogging, is well aerated, and has not grown cilantro for more than five years; never plant continuously on the same plot. In summer, cilantro is mainly broadcast sown; irrigate thoroughly, and once the water has seeped in, sow evenly. The soil must be kept moist, watered once every 4 to 5 days, and when the temperature exceeds 30°C, shading and cooling measures should be taken.
1. Choose good seed. In summer, it is advisable to choose heat-tolerant varieties that bolt late and grow quickly.
2. Prepare the land well. Choose soil that is fairly fertile, with good water and nutrient retention, can be watered in drought and drained in waterlogging, is well aerated, and has not grown cilantro for more than five years; never plant continuously on the same plot. Apply 4000 kg of decomposed farmyard manure and 100 kg of cake fertilizer per mu. The residue of the previous crop must be cleared away to reduce the occurrence of pests and diseases. Plow deep and harrow fine, then make beds; a bed width of 1 to 1.5 m and a length of 8 to 10 m is suitable.
3. Sprout the seeds well. Cilantro has no strict sowing-period requirements; generally it can be harvested 40 to 50 days after sowing. Before sowing, soak the seeds to sprout them. First soak the seeds in clean water for 24 to 30 hours, then take them out and spread them on a moist, uncontaminated burlap sack to a thickness of 2 to 3 cm, cover with a moist burlap sack, keep the temperature at 20°C to 25°C, stir 1 to 2 times a day, maintain a certain moisture level, and after 3 to 4 days they will have sprouted and can be sown.
4. Promote good seedlings. In summer, cilantro is mainly broadcast sown; first sow two beds and leave one bed, take the covering soil reserved for the first-sown beds and place it on the two adjacent reserved beds, then irrigate thoroughly, and once the water has seeped in, sow evenly, covering with 2 cm of soil after sowing. Then sow the remaining empty bed in the same way as the first-sown beds. The seeding rate is about 2 kg per mu.
After all sowing is complete, press once to conserve soil moisture. If the weather is dry and soil moisture is low, affecting emergence, a light irrigation may be given. When the seedlings are 4 to 5 cm tall, thin them and weed, with a seedling spacing of 2 to 4 cm; after thinning, apply a light manure water as a top dressing once per mu combined with irrigation. When the seedlings are 7 to 8 cm tall, apply the first top dressing; at this time the fertilizer amount should be larger, applying 20 to 30 kg of ammonium sulfate per mu.
5. Control the temperature well. The soil must be kept moist, watered once every 4 to 5 days, and when the temperature exceeds 30°C, shading and cooling measures should be taken. At harvest time, harvesting in batches combined with thinning is beneficial to plant growth.