Few vegetables have suffered at the hands of the commercial food chain as much as the tomato. The simple fact of the matter is that most of the tomatoes that we buy year-in, year-out in our supermarkets taste of absolutely nothing at all. It is not until you grow your own that you realise this! Commercial growers pick varieties which have thick skins so that they last longer and are less prone to wastage in storage and distribution. The home-grown tomato on the other hand is a delectable treat, a meal in itself, best eaten fresh in the warmth of the greenhouse for maximum effect. Sure tomatoes do require a certain level of TLC – pinching out sideshoots, watering, feeding etc. But it’s worth the effort!
There are basically two types of tomato plants. Vine (or cordon) tomato plants are an orderly affair and have a tall central stem which produces two types of side stems (1) trusses or fruit bearing branches on which the tomatoes grow and (2) leaf bearing stems. Bush tomatoes are more compact but disorderly – they have trailing side branches.
Tomatoes have a long growing season and can be started in February indoors on a heating mat to get a head start. Otherwise wait until March. Sow seeds in pots or module trays indoors in a warm, sunny spot. When they have developed three true leaves prick out in to 3-inch pots. They won’t be going in to the soil until May. Keep the potting compost moist.
Though lots of GIYers have grown tomatoes succesfully outdoors, to my mind this mediterranean vegetable fares best in the warmth of a greenhouse, polytunnel or conservatory. They can be sown direct in the soil but will also grow well in pots as long as the container is good and deep (toms are quite deep rooting). Grow bags also work well. Wherever you plant them, make sure it’s the warmest, sunniest place possible. They like rich, fertile soil – dig in a well-rotted manure or compost before planting or use poultry manure.
Vine tomatoes grow very tall and will require support – an ideal way to provide this is to put strong twine around the roots of the plant before you plant it in to the soil. This twine is then buried in the soil and tied to a horizontal on the roof of the greenhouse or tunnel, providing a taut vertical for the main stem to grow up. Leave approx 40cm between plants.
As the plant grows, pinch out side shoots which regularly appear in the angle between the main stem and leaf stems. These waste the plants energy if you allow them to grow. When the plants are 4ft tall remove the leave stalks below the first fruit truss. This will improve air circulation around the base of the plants and makes it easier to water. Remove yellowing leaves as they appear.
Water evenly and regularly - irregular watering causes fruit to split. Never water the foliage on a tom plant as it will burn in the sunlight. Approx water requirements are 11 litres per plant per week.
Left to its own devices, the main stem of a healthy tom plant will just keep on growing up and up. But growing toms is a balancing act between allowing the plant to grow to a good height and forcing it to focus on producing fruit. Keep an eye on the number of trusses that are forming on the plant. If the plant is healthy allow seven or eight trusses to form. If it is not healthy, stop when the plant has formed five or six trusses by pinching out the growing point (top of the main stem).
Once toms are starting to appear, feed fortnightly with a high-potash feed. Liquid tom feeds are available commercially or you can make your own comfrey tea by soaking 500g of comfrey leaves in 3 gallons of water and leave to stew for a month. Dilute before applying to plants - one part comfrey tea to ten parts water.
Harvest when the fruits are ripe. Fruit will split if left on the plants so remove as it ripens – surplus fruit can be made in to sauces for the freezer. Later sown plants may continue to produce fruit right in to late October and early November. You are likely to be left with lots of green fruit at the end of the season – use these for chutneys. Never serve tomatoes straight from the fridge – flavour is best when served warm.
The best way to avoid problems is to ensure that air is circulating around the plants. The same blight that affects potatoes can be devastating to tomatoes, particularly outdoor ones (though it can make its way in to greenhouses and polytunnels too). It causes leaves to curl and blacken. Try removing affected leaves or plants quickly but there’s little you can do once it takes hold. The most common pests are whitefly, aphids and spider mites. Rolling or curling of tomato leaves is common and can be due to wide variation between day and nighttime temperatures. It is not a problem.