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Essential Facts About Tomato Seedlings

Essential Facts to Know About Tomato Farming from Seedlings

  Farming with tomatoes in South Africa can be a highly profitable operation, provided the farmer starts the crop with the right variety of quality seedlings, suited for the specific growth area.

Many farmers grow their crops in greenhouse set-ups, but even then, the choice of tomato seedlings along with other factors that affect cultivation success must be considered. This article discusses key facts about commercial farming with tomatoes.

Temperature Range Matters with Tomato Seedlings


As a plant that does the best in a warmer climate, it is frost sensitive. To this end, should a farmer want to grow the crop from seedlings in the cooler months of the year as well, it is essential to choose a variety that can perform in a cooler climate, and to do so in temperature-controlled greenhouse environments, or in regions that do not experience frost. What should be noted is that tomatoes need both a warmer and cooler growth environment, which makes it a challenging crop for newcomers to crop farming in South Africa. The climate conditions for seedlings differ from that needed for flowering and fruit setting. The allowable temperature range falls between 10°C and 38°C as growth, fruit setting, and quality are severely hindered by too cold or too hot temperatures. For optimum performance, tomato seedlings should be grown in a temperature range of 21°C to 24°C while reasonable growth can be expected as long as the temperature range is 10°C to 30°C. If grown outdoors, plant the tomato seedlings in a region that experiences an average monthly temperature of 21°C to 23°C.

Water Stress Affects Fruit Quality

Tomatoes, from seedlings to mature plants, are sensitive to water stress. If the plants go without water for long periods, the fruits will crack, affecting crop yield success.

Importance of Direct Sunlight

The plants benefit from sufficient sunshine during the fruiting period as this helps to get the rich dark red colour in the fruits. With days in the winter being shorter, it is recommended to grow tomatoes from seedlings in a greenhouse where artificial lights can be used to give enough direct light during the shorter winter days. If grown in the summer months only, then the plants can do well outdoors because of the direct, natural light from the sun. If artificial light is used in a greenhouse to give 14 hours plus light, it is imperative to adapt the height of the lights to the height of the plants.

Best Performance in Sandy Loam Soil

Although farmers can transplant the seedlings to a wide range of soil types, the plants perform best in nutrient-rich, sandy loam soil with good drainage capacity. The plants require more clay in the sub-soil area with the top layer not having too much sand. If transplanting to a heavy clay soil, it is imperative to perform deep tillage beforehand to allow for proper root development and penetration of the soil. Tomatoes do best in slightly acidic soil, free from salts. Although the plugs require nutrient-rich growth environments, the plants do not do well in soil with high organic matter and excessive moisture.

Spacing Needs

The plants require enough space in between plants and rows to allow for sufficient airflow.

Farming Tomato Seedlings

Essential to Control Weeds

Weeds take up nutrients and water that could have been used by the plants. Light hoeing during the initial growth period after transplanting of the plugs helps to remove weeds and to loosen the soil for maximum growth potential. Straw and plastic mulch help to keep moisture in the soil and to maintain adequate soil temperature. It has been noted that red plastic mulch helps to increase the yield of the crop. If plastic mulching is used, make sure the holes are big enough to prevent the plastic from touching the stems as this can cause burn damage to the stems during hot summer days.

Where to Get the Best Tomato Seedlings?

Purchase grafted or normal tomato seedlings from one of the leading and most reputable suppliers of vegetable plugs in South Africa. Hishtil SA provides a wide range of quality, disease-free plugs, which are chemically treated before delivery to the farmer. The plugs are delivered throughout South Africa.