Tomatoes: there is one crop which seems to symbolise late summer. The fruit is a lush red, the leaves have a slightly smoky, fragrance about them and they are all the better for their healthiness.
Sowing Tomato Seeds
Each variety of tomato has slight differences in growing habit but all have similar early growth. Most seed is sown between February and April under cover in the UK.
Seeds are sown in individual pots or modules filled with a high quality seed compost. These are watered well usually with a fine rose to the can. The modules are placed in the warmest spot of the greenhouse or in a heated propagator.
The seeds germinate in 7 to 21 days. When the shoots emerge, take the pots from the propagator. Continue to water but do not overwater as damping off is common at this point.
The seedlings will develop their first set of ‘true’ leaves and will then be big enough to handle, whereupon they are repotted. All young plants need to be handled by their leaves rather than their stems as this protects the young plants from damage.
The seedlings are finally repotted when they have reached about a foot in height into their final spot, either a large pot or outside in a prepared bed.
The tomatoes are allowed to grow on so regular watering is required. A high potash liquid fertiliser feed encourages development of flowers and the setting of fruit.
Once the plants have set seven trusses, the tip is pinched out. This encourages fruit to ripen rather than the whole plant simply grow larger.
The fruits are harvested as soon as they ripen by turning red which is usually between July and October. When it comes to outdoor tomatoes, ripening is a bit hit and miss. Just like their Solanum relatives such as aubergines, chillies and sweet peppers, ripening any outdoor fruit from this family depends heavily on weather conditions. In the UK’s rather imperfect summers, a lack of heat and Sum leads to poor levels of harvest when early autumn finally arrives. The techniques I recommend which have ben tried with some success are the following:-
- Potted plants are best moved from outdoors to the greenhouse, conservatory or a sunny porch. Extra heat will ripen up stubborn fruits.
- If you slide fork prongs under outdoor plants to release some of the soil, then this fools the plant into maturing much earlier than it thinks.
- Inducing stress by reducing the level of watering is always a failsafe method both for indoors and outdoors planting. Simply stop watering any outdoor plants and rely on natural rain to help. Maturing of a crop is greatly helped by heat in September but that is a gamble. Fruits tend to ripen when water stress is felt by the plant. You need to water plants if they wilt too much.
- I’ve untied outdoor cordons of tomatoes from their vertical supports and placed them gently on straw beds. The cordons are covered with a tunnel cloche. That extra heat also helps ripening a bit quicker.
- Remove the most immature fruit and any just forming. Indeed take out flowers from September onwards so the plant just concentrates on ripening what fruit it has.
They can then be processed into sauces, chutneys or even dried as required.
Blossom end rot is a problem with soft fruit grown under glass. It is prevented by making sure that watering is continued on a regular basis to prevent this issue.
Glasshouse red spider mite is an issue with all fruit grown under glass.
Varieties Of Tomatoes
There are some excellent varieties to try:-
Ailsa Craig..an early maturing, semi-greenback variety producing bright red, medium sized fruits. Very popular with amateurs and famous for its great flavour.
Gardeners Delight..a very old variety but still as popular as ever, due to it being an exceptional performer, producing small fruits that have an excellent flavour.
Gigantomo.. world beating extra large fruits up to a huge 700g to 1 kg. The fruits have good flavour and one can ben sliced to feed a family of four ! Always grown in a greenhouse.
Principe Borghese…the classic, plum type of tomato that retains its bushy habit. The plants are high yielding producing a mas of fruits ideal for salads.
Red Cherry… A sweet, juicy small tomato, ideal for salads. It is also early cropping so will be ready by mid-July.
Red Pear…. An heirloom variety of cherry tomato, with unusual shaped, fleshy but sweet fruits.
San Marzano… an italian plum tomato mainly used for cooking as it contains very little water and few seeds. many regards it as the best variety for making sauces and passata. A heritage variety.
Shirley – an early, short-jointed type producing large trusses that produce heavy yields and very fine, round fruits. A good choice for crops that are likely to be grown in colder climates such as northern Europe.
Snow Berry is a heritage variety producing masses of small unique creamy-yellow fruit. A very productive variety with long trusses bearing up to 50 fruits per truss, with a classic flavour. Good outdoor/greenhouse variety and plants need supporting.
Sungold. A variety regarded as one of the best tasting salad tomatoes. Vigorous plants produce small delicious orange coloured fruits on long trusses.
Tigerella….This particular tomato has a striped skin which gives it a highly distinctive eye-catching appearance.