Choosing a plot
Tomato plants thrive in warm sunny spots. If growing outside, most people start seeds inside in a sunny position and in moist soil, before transplanting outside once the frost has passed. Tomatoes grow best in slightly acidic soil, with a pH of 6.0-7.0 and a good balance of nitrogen in the soil helps the tomato plants to grow healthy leaves which are important for photosynthesis. Natural sources of nitrogen include alfalfa meal compost and fish meal.
Start tomato seeds by planting in a container which is about 3 inches deep, and plant seeds about ¼ inch apart and ½ inch deep. As soon as the stems start appearing above the soil, it is important to provide them with plenty of bright light. First, two small cotyledon leaves will appear, soon to be followed by real leaves. At this point, transplant the seedlings into their own containers and if you want them to grow outside, now is the time to do it.
Only once temperatures are consistently above 15ᵒC, and the plant is at least 6 inches tall is it best to transplant your tomato plants directly into the ground outside. It is because of the changeable weather conditions in the UK that many people choose to keep their tomato plants in a greenhouse.
Watering your tomato plants correctly is the key to keeping them healthy. It is generally thought that about 2 inches of water a week is good, though depending on the type of tomato, where it is planted etc. this will vary. Tomato plants need to be watered regularly, every 2-3 days until the weather is cooler and the fruit is established, when this can usually be reduced to about once a week. Watering directly into the roots reduces the susceptibility of the plants to pests and diseases.
The aim is to produce a single-stemmed plant as this helps to channel the energy into producing fruit. In order to do this, snip away shoots that are growing out of leaf joints.
Tomatoes are ready to harvest when they are fully coloured and only a little soft when pressed. This is usually about 60-85 days after planting seedlings. Tomatoes do continue to ripen once they have been picked, but they are more flavoursome if left on the plant to ripen, as this is their main source of oxygen.