When to sow vegetables and greens in open ground: temperatures for different crops

The onset of spring marks the beginning of gardening, prompting us to consider the right time to sow vegetables, plant seedlings, and ensure optimal conditions for growth. SSPDaily has outlined the growth characteristics of various plant types, as well as the temperature requirements of the environment and soil, which contribute to successful sowing and growth.

Cold-resistant crops like celery, parsley, dill, carrots, radishes, beets, beans, peas, perennial onions, and cabbage can withstand cool weather conditions. However, heat-sensitive plants such as cucumbers, tomatoes, and peppers cease growing at low temperatures and can be affected by short-term frosts.

Soil temperature plays a crucial role during sowing and can be accurately measured with a suitable tool or a conventional thermometer. To obtain precise data, measure the soil temperature twice a day: in the evening after sunset and in the morning about 2-3 hours after sunrise. Sowing should be conducted when it meets the requirements of a particular plant.

For cold-resistant crops, an ideal soil temperature of +5°C or higher ensures successful germination. It is advisable to postpone sowing if the temperature drops below this threshold.

Moderately cold-tolerant crops require an optimal soil temperature of +8°C for sowing, while heat-loving crops prefer soil temperatures of +10°C or higher to ensure favorable growth conditions.

Air temperature also influences the timing of sowing various vegetables and seedlings. Here are specific temperature requirements:

Peas can germinate at temperatures of +2-6°C and tolerate frosts down to -6°C for short periods.

Zucchini, squash, and pumpkins require a minimum temperature of +10°C for sowing seeds, while the plants themselves need temperatures of 25-35°C. Frosts are fatal for these plants.

Cabbage can germinate even at air temperatures as low as 3°C, with optimal growth occurring at temperatures around +20°C. Mature cabbage plants can withstand frosts down to -7°C, with hardened seedlings tolerating short-term frosts.

Carrots prefer a germination temperature of +4°C, with optimal growth at temperatures of 15-22°C. Root crops can be damaged if the temperature drops below 0°C, while seedlings can tolerate frosts down to -4°C, and mature plants can withstand temperatures down to -7°C.

Cucumbers require a temperature range of 13-15°C for successful germination and 25-30°C for optimal growth. Growth halts and flowers drop at 13°C, while seed decay occurs at 8°C. Cucumbers are susceptible to disease and can perish at low temperatures.

Parsley and celery seeds can germinate at 2-4°C, with adult plants thriving at 15-20°C. Parsley and celery seedlings can tolerate frosts down to -4°C.

Heat-loving peppers germinate at temperatures above 18°C, though it's advisable to wait until 25°C. Peppers need a temperature of 20-25°C to maintain growth, with processes slowing at 13°C and near-zero temperatures leading to plant death.

Radish and turnip seeds can be sown at 8°C, with sprouts resistant to frosts down to -4°C. Prolonged exposure to cold and temperature fluctuations can trigger premature germination. For mature plants, the optimal air temperature ranges from 18-20°C.

Lettuce can withstand frosts down to -5°C and grows successfully at 5°C, but it develops best at 15-20°C.

Beets should only be sown when the soil has warmed to 6°C, with the ideal air temperature for growth between 15-25°C.

Heat-loving crops like tomatoes require a temperature of 20-25°C (minimum 12°C) for seed germination. The daytime temperature should be at least 24°C, dropping to about 18°C at night. Tomato plants are highly sensitive to temperatures as low as 2°C, often resulting in their demise.

Dill seeds germinate at 3°C and grow well at 15-20°C.

Bean seeds are prone to rot in cold, wet soil, requiring a minimum temperature of 15°C for successful germination, with the best germination occurring at 18-25°C.

Spinach germinates at 3°C and grows optimally at temperatures around 15°C, with bolting occurring above 20°C. Young spinach plants can tolerate short-term frosts down to -7°C.

Sorrel seeds germinate at 3°C, while the optimum temperature for growth ranges from 15-23°C.

Onions have moderate temperature preferences, though prolonged exposure to low temperatures can trigger premature sprouting. Black onions germinate at 7°C, with the optimal temperature range for bulb or green onion growth being 16-20°C.

Accurate knowledge of temperature requirements for sowing and planting different crops empowers gardeners to make informed decisions as they embark on their journey to a bountiful harvest.