Starting with tomatoes – Part 1

This is an expensive crop to grow, so do your homework before you start, cautions Bill Kerr.

It is important to plant a tomato variety with eelworm resistance.
Photo: FW Archive

Growing tomatoes is expensive and not for beginners, so the first thing to consider is climatic restraints. In short, tomatoes do not tolerate extremes. Tomatoes are frost-sensitive and you should not try to grow them if frost is a risk in your area. Even though the plants will grow in low temperatures, pollination will be affected and you are likely to end up with very small tomatoes.

When temperatures are excessively hot – about 35°C and higher – pollination again becomes a problem. Under these conditions, the plants may grow lush and appear to thrive, but the yield will be low. Tomatoes grown in areas of high rainfall and humidity are at a great risk of infection by leaf diseases, which become difficult and expensive to control.

On the ground
Compact tomato plants that do not require stakes are popular in certain areas, with most sales going to processors or the hawker trade. However, growing these tomatoes requires specific conditions. Because the plants and fruit lie on the ground, they are more vulnerable to leaf diseases and rotting where they make contact with the soil. 

For this reason, the crop has to be grown either in a dry area or in a dry season. If you choose this method, use drip or furrow irrigation to keep the soil dry where fruit, leaves and stems are in contact with it. This method is perhaps the best way for a small-scale beginner. The input cost per kilogram of fruit produced is far lower than for other systems.

On trellises
Another method to grow tomatoes is to lead the plants between wires or twine supported on poles positioned about 3m apart. You can choose either short or tall growers, but the length of the trellis should match the plant’s growth type.
Tall growers tend to produce a higher yield and produce for longer, but the cost of additional wire or twine and longer poles will be higher.

They also give you the option of pruning off the side shoots, leaving one or two stems per plant. This reduces leaf diseases and makes spraying easier, cheaper and more effective. High yield is still possible as the trusses of fruit are larger. With these supported systems, the plants are positioned for easier, more effective spraying and dry out quickly after rain. Most market tomatoes are produced this way.

Eelworm, diseases
If you’re a beginner, do not try to produce your own seedlings. This is a specialised activity and can have disappointing results. It is important to plant a tomato variety with resistance to eelworm and the diseases common in your area and season. Seedling growers can offer you good advice on the best variety to choose. They have your interests at heart and will provide valuable help because your success means more business for them. ?