When can I start planting tomatoes?

Tomatoes are loved by people for their rich nutritional value and unique flavor. In addition, their good planting returns make greenhouse tomato cultivation a popular crop among many vegetable growers. So when can we start planting tomatoes?

Factors affecting tomato planting time

The timing of tomato sowing is affected by many factors, including planting time, seedling raising methods, planting facilities, planting areas and varieties. After determining the planting time by comprehensively considering factors such as the type of planting facilities, local climatic conditions, and the end of the frost period, the appropriate sowing time can be derived by reverse calculation based on the seedling cycle.

In a solar greenhouse, tomatoes can be planted at any time except the hot summer season. For plastic greenhouses, early planting in spring is usually carried out from February to April, while delayed planting in autumn is mostly carried out from July to August.

For open-air planting, it is necessary to wait until the frost period is over before transplanting, and the sowing time is calculated in advance based on the age of the seedlings. For example, when growing seedlings in a greenhouse or heated seedbed, the seedlings will need to be about 65 to 75 days old. It takes 70 to 80 days to grow seedlings in a sunny bed. In the south, due to the earlier planting period, the sowing time can be slightly earlier than in the north. In the same area, mid-maturing varieties are usually planted earlier than early-maturing varieties.

It can be seen from this that the specific sowing time depends on the age of the tomato seedlings, and different varieties and seedling raising methods have different requirements for suitable seedling age.

For tomato seedlings of a certain age, the length of the seedling raising period is mainly determined by the temperature and other management measures during the seedling raising period. According to the most suitable temperature for tomato growth (25℃ during the day, 15℃ at night, and daily average temperature of 20℃), it takes about 50 days from seedling emergence to budding for early-maturing varieties, about 55 days for mid-maturing varieties, and about 60 days for late-maturing varieties. In addition, it takes 5 to 7 days from sowing to seedling emergence, and 3 to 4 days from transplanting to seedling acclimatization. Therefore, the general age of tomato seedlings is 60 to 70 days.

If the seedling age is too short, the seedlings may be too small and flowering and fruiting may be delayed; if the seedling age is too long, the seedlings may age. For seedlings that are delayed in autumn, due to the higher temperature during the seedling stage, the seedling age is generally controlled at 35 to 40 days. Therefore, the appropriate sowing period should be determined based on local climate characteristics, protected land type, cultivation method, variety characteristics and planting time.

Tomato planting time

1. Spring tomato planting

For open-air spring tomato planting, the ideal seedling age is 50 to 70 days, which means that sowing should be done 50 to 70 days before planting. Taking Shenyang (41 degrees north latitude) as an example, spring tomatoes are sown and raised in protected areas in February and transplanted to the open air after the late frost in early May.

Spring tomatoes are usually planted after a late frost, when the local temperature reaches a stable 12°C at a depth of 5 to 10 cm. The average late frost date in Shenyang is May 2, and the suitable planting period is generally between May 6 and 10. Planting is mostly carried out during the Qingming solar term in the Yangtze River Basin, during the Grain Rain solar term in North China, and around the Beginning of Summer solar term in Northeast China. In areas with wind barriers, mulch coverage, and high, dry sandy soil that is sheltered from the wind and facing the sun, planting can be done earlier. The planting time also needs to be adjusted according to weather conditions. If it is rainy and windy, it should be postponed appropriately. Tomato planting in Shaanxi is mainly based on the time to market, with two seasons a year. The delayed autumn cultivation is for seedling raising in July and August, and the market starts in November; the early spring cultivation is for seedling raising in November and December, and the market starts in May and June.

2. Planting tomatoes in autumn and winter

Autumn and winter tomatoes are generally sown and seedled from mid-to-late July to early to mid-August, and transplanted from mid-to-late August to early September. The film is removed from mid-to-late September to early October, and harvesting is carried out from late November to early February of the following year.

3. Winter and spring tomato planting time

Winter and spring tomatoes are sown from early November to early December, transplanted from mid-to-late January to early February of the following year, and harvested from early to mid-March to June.

4. When to plant overwintering tomatoes

Overwintering tomatoes are long-term cultivation, with seedlings generally raised from mid-to-late September to early October, transplanted in November, and harvested in January of the following year.

Tomato growing areas can be divided into four main growing season zones:

(1) Northeast and Northwest regions

Including the northeastern and northwestern provinces and the high-altitude and cold areas in the northern part of North China, it is mainly sown in spring and harvested in autumn, cultivated in summer, and one crop per year. Sowing and seedling raising is in March and April or direct seeding in the open air in May, harvesting is in July to September, and the harvesting ends before the early frost. Processing tomatoes are mainly grown without supports.

(2) North China

Mainly in the North China Plain, the frost-free period is longer than that in the Northeast, the summer is hot and rainy, and the tomatoes generally grown do not easily survive the summer. Seeding and seedling raising are carried out in January and February, transplanting is carried out from late April to early May, harvesting starts in late June and ends before early August.

(3) Middle and lower reaches of the Yangtze River

It is mainly cultivated in spring and summer, with a small amount in autumn. Spring tomatoes are raised in November and December, planted out in mid-to-late March of the following year, and harvested starting in late May and ending in mid-to-late July. Autumn tomatoes are raised or sown directly in July and August, transplanted in August to early September, and harvested in early October.

(4) Pearl River Basin

Spring is cloudy and rainy with weak sunlight and high humidity; summer is hot and rainy with typhoons; autumn is sunny with plenty of sunlight and little rain; winter is warm. Seeding and seedling raising are in August-September, transplanting is in September-October, and harvesting starts in mid-November and ends in late February of the following year.

The above is an introduction to the key points of tomato sowing time. It can be seen that the time of tomato planting is linked to many factors, and everyone should start from the actual situation.