The following sowing and transplanting methods are available to the amateur gardener who wants to grow tomatoes outside without the use of a greenhouse.Tomato seeds can be sowed directly into a seed bed. However, this is by far the riskiest method in temperate climates. It is only suitable for those areas which have a last frost date in MARCH. In all other areas, the soil is unlikely to be warm enough at a time which will allow the tomato plant to develop and fruit. The soil temperature must be at least 15C (60F) at the time of sowing and during germination. It is possible to utilize a cloche or cold frame. This will warm the soil prior to planting and protect the plants in their early stages. Using a trowel, dig a shallow drill 2.5cm deep (1in) deep in the prepared bed. Place two seeds every nine inches in the drill and cover the seeds to a depth of 2.5cm (1in). Water well if the conditions are at all dry.The seedlings should emerge in about 10 days. When they are 5cm (2in) tall, thin to one plant every 45 to 60cm (18 to24in).Sowing tomato seeds indoors is one of the commonest methods and produces good results. Sow each seed (two if you have a surplus) in a 7.5cm (3in) pot, lightly covering them with potting compost. Ensure the compost is moist but not waterlogged. Place them in a warm (up to 27C or 80F) draught free place – the seedlings should emerge in 7 to 10 days time.Immediately this happens, move the plants to a light position (a light windowsill is ideal), but out of direct sunlight to avoid burning the leaves. Where more than one seed has been sown per pot, thin out the least healthy seedling as soon as they are large enough to handle. When the roots start to come through the base of the pot (about 4 weeks after sowing), transfer the plants to larger 12.5cm (5in) pots. The plants will be large enough to transplant outside about 7 weeks after sowing the seed.Sowing tomato seeds outdoors in pots is similar to sowing the seed indoors in pots with the exception that the pots are stored outside whilst the seed germinates. The advantage over indoor sowing is that space is not a limiting factor to the amount of plants to be raised.Timing and position of the plants are the key factors to success. Keep the pots in the warmest part of the garden (against a house wall is ideal) to hasten germination and subsequent growth. The use of cloches will assist greatly in retaining heat. Timing is the most difficult aspect of this method – keeping the plants under cloches and or against a house wall will raise the temperature and permit earlier growing, but it is not an exact science. The basic rules of no frost and a minimum soil temperature of 15C (60F) must be achieved.One combination which can work well is to sow the seeds inside (where they do not have to be in a light position) and the transfer them outside when the seedlings emerge.Just before transplanting the tomato plants to their final position drive a strong stake into the ground 5cm (2in) from the planting position. The stake should be at least 30cm (1ft) deep in the ground and 1.2m (4ft) above ground level – the further into the ground the better the support.Where tomato seedlings have been started in pots, they should be transplanted into their final positions when they are about 15cm (6in) high. Two to three weeks prior to this, the plants should be hardened off.For each plant, dig a hole (45cm / 18in apart) in the bed to the same depth as the pot and water if conditions are at all dry. Ease the plant out of the pot, keeping the root ball undisturbed as far as possible. Place it in the hole and fill around the plant with soil. The soil should be a little higher than it was in the pot.Loosely tie the plant’s stem to the support stake using soft garden twine – allow some slack for future growth.

There are a couple of ways for approaching tomato growing in a greenhouse, you can either dig and prepare the soil of the greenhouse ready to accept the tomato plants or you can grow the plants in a container such as a plant pot (12″ diameter) or growbag.

Realistically most growbags that are available which can be 35 or 40 litres in size are only enough to support two plants. There are ways in which you can push this out to 3 plants but for the cost of a growbag its probably as well just to stick to 2 plants, particularly if you take good care of them and produce lots of fruit.

If you go for pots then you should steralise them before use, to do this you can use a dilute solution of a suitable disinfectant, something like Jeyes fluid is perfect for this task.

While we are on this subject, you really should wipe down the inside of your greenhouse with disinfectant as well to ensure any residual contaminants that could also cause disease are removed from the glass.

One of the reasons I am suggesting using large pots or growbags for growing tomato plants is because the soil in the greenhouse is going to need to be dug out and replaced every 2 or 3 years anyway to ensure that you get rid of any build up of disease and also because the soil will be pretty much spent in terms of nutrients.

Space is limited in a greenhouse so the best option for plant varieties is to use the indeterminate variety of tomato plant i.e. a vine plant. You can prune the plant to the required size, leaving about 4 to 6 trusses on the main stem, which is about 6′ to 7′ in height, greenhouse size allowing. This will give you lots of fruit over an extended period.  You will have to pinch out the main stem when you have enough trusses to stop further growth.

As an aside, using the bush variety is less convenient for greenhouses because they, as the name suggests, form a determinant size of bush without pruning which is probably a little too large in diameter for the average greenhouse. The fruit also has a tendency to all come at once.

Irrespective of the growing method you choose, you should start to feed the tomatoes at the first sign of fruit and for the duration of the growing period, twice a week should be sufficient. Also as you are in a greenhouse regular and consistent watering is also very important and I recommend 2 to 3 times a day with water that has been allowed to warm in the greenhouse.

As the end of the season nears a way of helping the last remaining fruit ripen is to hang a couple of bananas in the apex of the greenhouse. If that fails to ripen the last bit of fruit you can always use the green tomatoes for making a delicious chutney.

The tomato originated in the Andes, South America where tomatoes grow wild. It is believed that they were first cultivated by the Aztecs and Incas, possibly as early as 700 AD. The tomato plant arrived in Europe in the 16th century, supposedly brought back from Central America by the Spanish Conquistadors, although another legend suggests that two Jesuit priests took them to Italy from Mexico.At that time tomatoes were also known as wolf’s peach and Peruvian apple. In the UK, the Elizabethans thought the bright red colour of tomatoes was a danger signal and regarded them as dangerous fruits. In fact, it is true that tomatoes are related to the nightshade family.Tomatoes are sub-tropical plants and therefore require a full sun position when grown in temperate zones. A position against a wall or fence will give an even better chance of success as long as they can receive sufficient water.Tomato plants grow very well in raised beds, they appreciate the soil conditions which provide moisture without water-logging.Two or three weeks before planting, dig the soil over and incorporate as much organic matter, such as compost or well rotted manure, as possible. The aim is to make the soil able to retain the moisture needed so much by tomatoes.Tomatoes are unable to tolerate any degree of frost, the timing for planting or sowing outside is therefore key to successfully growing tomatoes. If the tomato seeds are to be sown directly outside (not really suitable in cooler climates), they must be sown when the soil temperature is (and will remain) above 10C (50F) – any lower and the seeds will not germinate. In practical terms this normally means 3 weeks after the last frost date in your area.Where the seeds are sown under cover (poly tunnels or cloches) or indoors, aim to sow the seeds so that they reach the stage where they can be transplanted outside, three weeks after the last frost date.Tomato plants plants take roughly 7 weeks from sowing to reach the transplanting stage and they should be transplanted outside one or two weeks after your last frost date. Therefore you should sow them 7 weeks before you plan to transplant them outside.Bush varieties do well for cultivation outdoors because they require no pruning for most of the season. Remove any yellow or decaying foliage as soon as possible to avoid the spread of disease.If your bush tomatoes become too large to support themselves, either trim out a few major branches or add more support canes – the side branches can then be tied into the additional support canes. Limit the number of trusses of tomatoes to seven or eight by pinching out any surplus ones.Upright varieties are commonly cultivated in pots, grow-bags, the greenhouse and sometimes outdoors in open soil. When the first fruits begin to form, the plant will produce side-shoots in between the main stem and the leaf stems.These side shoots should be removed by pinching them out with the fingers. If allowed to grow they will produce a mass of foliage but few tomatoes. Any shoots which have been overlooked and allowed to grow should also be removed.Lower leaves which show any signs of yellowing should also be removed to avoid the risk of infection.When the plant has developed six or seven trusses of tomatoes (normally around July time), ’stop’ the plant by breaking off the growing tip. If any more than seven trusses of tomatoes begins to develop, pinch them out to encourage the plant to produce good quality tomatoes rather than an abundance of low quality late-maturing fruit.Pick as soon as the fruits are ripe (colour and size will identify this) for the best flavour – eat as soon as possible. This also encourages the production of more fruit. As soon as a frost threatens, harvest all the fruit immediately and ripen them on a window sill. With upright varieties, it is possible to gently flatten the plants onto the soil and cover with horticultural fleece to protect them from the frost.