Tomato

The tomato (Solanum lycopersicum), also called the love apple, is a herbaceous, usually sprawling plant in the nightshade family widely cultivated for its edible fruit. Savory in flavor, the fruit of most varieties ripens to a distinctive red color. Tomato plants typically reach to 1–3m (3–10ft) in height and have a weak, woody stem that often vines over other plants. The leaves are 10–25cm (4–10in) long, odd pinnate, with 5–9 leaflets on petioles, each leaflet up to 8cm (3in) long, with a serrated margin; both the stem and leaves are densely glandular-hairy. The flowers are 1–2cm (0.4–0.8in) across, yellow, with five pointed lobes on the corolla. It is a perennial, often grown outdoors in temperate climates as an annual.

Soil
Two or three weeks before planting dig the intended site over and incorporate as much organic matter as possible. The intention is to produce a water-retaining mix that will also warm up quicker. Spread a few handfuls of blood, fish and bone meal per square meter/yard as you dig the area over, this will provide a good, long-lasting base of trace elements essential for good tomato growth.

Container Growing
To grow tomatoes in containers, use a mixture of half potting compost, half loam soil. This will ensure the medium is thick enough to stand a supporting cane in it without it blowing over once the plants are established. It will, however, mean you will need to keep the plants well watered. A good supply of water will help reduce the risk of blossom end rot or splitting, prevalent conditions in container grown tomatoes.

Location
Being sub-tropical plants, tomatoes will require a full-sun position if grown outdoors in the UK. Grow them next to a south-facing wall to provide as much reflection/radiation of heat and light as possible for the best results. Tomatoes also do well in rasied beds where the combination of water-retaining soil and good drainage are ideal.

Sowing
Unless sowing outside, aim to have established plants that are ready to transplant approximately 2 weeks after the last frost date. This usually takes about 7 weeks.

Sowing Directly (Outside)
Tomato seeds require a germination temperature of 13°C (55°F) to germinate, this means you will need to wait for approximately 3 weeks after the last frost date before outside temperatures are warm enough. For this reason it is unlikely that you will have enough time for the tomatoes to produce ripe fruit unless you are in an area of the UK where the last frost date is in March. To warm the soil up before sowing, try covering the site with black polythene or use a cloche to warm the soil and protect young plants. Dig a shallow drill 2.5cm (1in) deep. Sow 2 seeds every 23cm (9in) and cover the drill over. Water well if the conditions are dry. The seedlings should appear in 10 days.

Sowing in Pots (Indoors)
Sow one or two seeds in a 7.5cm (3in) pot almost full of potting compost. Cover with 2.5cm (1in) of compost and place in a warm place (up to 35°C (95°F)). Seedlings should appear in 7 to 10 days. As soon as seedlings appear, move the plants to a light position (a windowsil is ideal). Try and avoid direct sunlight and sudden changes in temperature. Where more than one seed is sown and germinated per pot, remove the weaker of the two as soon as possible. About 4 weeks after sowing (when roots come through peat pots) tranplant seedlings to 12.5cm (5in) pots.

Sowing in Pots (Outside with Cloche Protection)
Follow directions for Sowing in pots indoors (above), but use cloche protection to provide warmth to germinating seedlings. For additional warmth and a reduction in temperature fluctuations; place pots next to a wall so that they may benefit from the radiated heat.

Transplanting
Where tomato plants have been grown in pots; they should be ready for transplanting when plants are 15cm (6in) high (about 7 weeks after germination). If plants where grown indoors or under protection; ensure they are hardened off for one or two weeks before transplanting to aclimatise them to outdoor conditions.

5cm (2in) north of each transplanting site, drive a supporting cane or stake into the ground at least 30cm (1ft) deep leaving at least 1.2m (4ft) exposed. For each pot, dig a hole 45-80cm (18-31in) apart depending on variety, and about 5cm (2in) deeper than their pot on the south side of each supporting cane

Gently easy the plant out of its pot keeping the root ball as intact as possible. Place the plant into the hole and fill over with soil so that 5cm (2in) more of the plant is covered. This promotes root growth in the plant and provides additonal support to the base of the stem.

Loosely tie the plant's stem to the supporting cane using garden twine, allowing some slack for future growth.

Watering
Tomatoes require a constant supply of water, epsecially during hot spells, to ensure fruit do not split. Watering less often with larger amounts of water increases the risk of fruit developing blossom end rot. Tomatoes also dislike waterlogged conditions. Plants in the ground will develop a larger root system which will reduce these risks, but container grown tomatoes will need regular attention.

Trimming
As the plant grows, new stems will emerge from the top of the junction between each leaf and the main stem. If left to grow the plant will require more support and essential nutrients will be diverted away from the fruit growing on the main stem. To manage these, remove shoots as soon as they are large enough to grip. You can remove them by hand without the need for cutting. Once the first flower cluster has begun to form, all leaves below it on the stem can be removed. This, again, ensures nutrients are prioritised to the fruit once they begin to form.

Support
As the plant grows, tie it losely to the supporting stake and check existing ties to ensure they do not cut into the plant. Support can also be maintained by training the plant around the stake in a clock-wise spiral.

Harvesting
Fruit are ready to harvest as soon as they are the right colour and size. Eat as soon as possible for best results. Regular picking will encourage the production of more fruit. As soon as frost threatens (October in the UK) remove all remaining fruit and ripen them together indoors. A banana, apple, or other ripening tomatoes help to speed up the process as they release ethelyne gas which causes ripening in fruit.