When to sow and plant - what should be the temperature of the soil and air to start planting
Spring is the beginning of work in the garden, in the vegetable patch, and in the field. It's a little warmer, and the question arises: is it time to sow vegetables and herbs, to plant seedlings in the open ground? To sow and plant plants correctly, you need to consider the growth and development characteristics of the plant species, the ambient temperature, and the optimal soil temperature. SSPDaily tells about it.
Cold-resistant crops like celery, parsley, dill, carrots, radishes, beets, beans, peas, perennial onions, and cabbage will grow in cold weather. However, cucumbers, tomatoes, and peppers stop growing at low temperatures and die in even short-term frosts.
The optimal soil temperature for sowingHow to measure soil temperature
In unheated greenhouses, the soil temperature should be measured at a depth of 7-8 centimeters, and in open beds, at a depth of up to 10 centimeters. It's best to use a special soil thermometer; if you don't have one, you can use a regular thermometer.
You need to measure the soil temperature twice a day - in the evening, after sunset, and in the morning, 2-3 hours after sunrise. If the temperature readings match and are suitable for the plant, you can sow.
To sow cold-resistant crops, you need a temperature of +5ºC. If it is lower, it is better to wait.
For moderately cold-resistant crops, the optimum soil temperature for sowing is +8ºC, for heat-loving crops - from +10ºC and above.
At what air temperature can you sow what vegetables, when to plant seedlings
- Peas germinate at a temperature of 2-6 °C and tolerate frosts down to minus 6 °C, but only if they are short-lived.
- The optimum temperature for sowing seeds of zucchini, squash, and pumpkins is plus 10 °C, and for plants, it's 25-35 °C. They do not tolerate frost.
- Cabbage can germinate even if the air temperature is 3 °C, but the optimal temperature is plus 20 °C. The same temperature is optimal for growth. Adult plants can tolerate frosts down to minus 7 °C. Hardened seedlings can also withstand short-term frosts.
- Carrots germinate at 4 °C, and the optimal temperature for their growth is 15-22 °C. Root crops are damaged if the temperature is below 0 °C; seedlings can withstand frosts down to -4 °C, and adult plants will survive at minus 7 °C.
- Cucumbers require a temperature of 13-15 °C for germination and 25-30 °C for growth. Flowers fall off, and growth stops at 13 °C; seeds rot in the soil at 8 °C, and the plant dies from disease.
- Parsley and celery seeds germinate at 2-4 °C, and adult plants need a temperature of 15-20 °C. Seedlings can withstand frosts down to -4 °C.
- Heat-loving peppers germinate at temperatures starting at 18 °C, but it is better to wait for 25 °C. It needs 20-25 °C for growth, and at 13 °C, growth processes slow down, and at temperatures around zero, the pepper dies.
- Radish, radish, and turnip seeds can be sown at 8 °C, although they can tolerate 4 °C. However, they can shoot during prolonged exposure to cold and temperature changes. For adult plants, the optimal temperature is 18-20 °C.
- Lettuce tolerates frosts down to -5 °C and grows at 5 °C. But it grows best at 15-20 °C.
- Beets should be sown only when the soil warms up from 6 °C. The optimal air temperature for growth is 15-25 °C.
- A heat-loving crop like tomatoes requires 20-25 °C (minimum 12 °C) for seed germination. The daytime temperature should be at least 24 °C, and the nighttime temperature should be 18 °C. Tomatoes die when the temperature drops to 2 °C.
- Dill germinates at 3 °C and grows at 15-20 °C.
- Bean seeds rot in the soil when it is cold and humid. The plant will germinate only at 15 °C, and beans grow well at 18-25 °C.
- Spinach germinates at 3 °C and grows at 15 °C. If the temperature is above 20 °C, stemming begins. Seedlings can withstand short-term frosts down to -7 °C.
- Sorrel seeds sprout at 3 °C. But the optimal temperature for growth is 15-23 °C.
- Onions are not very warm, but if exposed to low temperatures for a long time, they tend to shoot. Black onions germinate at 7 °C. The optimal temperature for growing onions for feathers is 16-20 °C.