Tomato Growing
Sow
Tomatoes generally come in two different types: cordon (or indeterminate) tomatoes grow tall (can reach up 1.8m (6ft) and require staking; bush (or determinate) tomatoes are bushy, and don’t require staking.
Tomatoes are very easy to grow from seed. Start them off indoors, using a propagator or place the pots in a plastic bag and keep on the windowsill. You can sow seed from late March to early April if you will be growing the plants outdoors. If you are planning on growing your tomatoes in a greenhouse, you can start sowing seed earlier, from late February to mid-March.
Grow
Transfer to 23cm (9in) pots, growing bags or plant 45-60cm (18-24in) apart outside when the flowers of the first truss are beginning to open; plants for growing outdoors should be hardened off first.
Tie the main stem to a vertical bamboo cane or wind it up a well-anchored but slack sturdy string. Those grown as bush or hanging basket types do not need support.
Remove the sideshoots regularly when they are about 2.5cm (1in) long. Those grown as bush or hanging basket types do not need to have sideshoots removed.
Water regularly to keep the soil/compost evenly moist. Feed every 10-14 days with a balanced liquid fertiliser, changing to a high potash one once the first fruits start to set.
For indeterminate (vine or cordon tomatoes), there is evidence that removing some leaves above the ripening truss (which allows the fruit to be warmer during the day but cooler at night) can encourage slightly earlier ripening without negatively affecting cropping. Removing leaves below the ripening truss does not improve ripening but can help reduce the spread of diseases such as tomato leaf mould or tomato blight where these are a problem.
Once the plants reach the top of the greenhouse or have set seven trusses indoors or four trusses outdoors, remove the growing point of the main stem at two leaves above the top truss.
If you allow the soil or compost to dry out and then flood it the change in water content will cause the fruit to crack; always aim to keep plants evenly moist.
Irregular watering, together with a lack of calcium in the soil leads to blossom end rot – the bottom of the fruit turns black and becomes sunken.
Common problems
Blossom end rot: Dark blotches appear on the ends.
Remedy: Water regularly and not sporadically and never allow the soil to dry out.
Tomato blight: Disease that causes fruit and foliage rot, most common in wet weather.
Remedy: Select resistant cultivars such as Ferline, Defiant, Crimson Crush.
Tomato leaf mould: Leaf mould can develop rapidly to cause significant yield loss in greenhouse-grown tomatoes. It is rarely seen on outdoor crops. Yellow blotches develop on the upper leaf surface. A pale, greyish-brown mould growth is found on the corresponding lower surface. Where the disease is severe the mould growth may also be found on the upper surface.
Remedy: Select resistant cultivars. Provide ample ventilation to indoor tomato crops.
Tomato splitting and cracking: Cracking or splitting usually does not affect the taste of the tomato, but split fruit left on the plant will often be infected by a fungus, such as grey mould and can cause a variety of physiological disorders.
Remedy: Control temperature and sunlight levels carefully. Feed regularly to maintain high soil fertility. Water to maintain a constant level of soil moisture.