Expert Advice for Growing Tomatoes
To many of us, a salad is not a salad without slices or wedges of luscious red tomatoes. The newer golden yellow varieties also provide a dash of colour to liven up salad greens such as, cucumber and .
Tomatoes are rewarding indoor plants, as I can testify from a huge crop harvested one year from only three sunny windowsills in my apartment. They are quite decorative while in flower and fruit, besides providing a continuous supply of one of the most tasty and versatile vegetables. The pleasure of eating firm, sweet salad tomatoes is easily matched by the many and various recipes for cooking them as a side vegetable and an ingredient in a great variety of starters and main dishes.
Selecting tomatoes for indoor growing
In order to grow tomatoes within the limited space of small containers, you must select the hybrids specially developed by seedsmen for the purpose. It is no use buying seed, or established pot-grown plants, of varieties which are genetically programmed to thrive best in open outdoor situations. In the open garden they can spread out, put down long root systems and grow tall in the sunlight. A number of the most popular garden varieties put up a very poor show indeed in restricted spaces and in an indoor environment.
Purpose-bred Fl hybrids are ideal for indoor growing. The seeds are a little more expensive, but the results make the initial outlay well worth while. My first choice is Pixie, a fast-growing, compact variety which thrives in pots and window boxes, tubs and hanging baskets. It is equally happy on an inside windowledge or outside on the patio or balcony. It produces many trusses of small, firm, sweet and juicy fruits. Tiny Tim is another attractive small-fruited variety, grown in the same way as Pixie. This may be quite difficult to obtain, and appears to have been superseded by more recently-developed small tomatoes. If you can find it, look out also for the yellow-fruiting form.
Another cultivar of the same type is the Cherry Tomato, which produces large quantities of smaller fruits, each about l in (2.5cm) in diameter. These, too, are firm-textured and have a sweet, fresh flavour.
Small Fry is an American cultivar producing plants growing to 30in (75cm) in height, with cherry-sized, very sweet fruits which mature within about 65 days of germination. A smaller plant, and earlier-cropping tomato, is Early Salad Hybrid – at only 12in (30cm) tall, this is ideal for indoor gardeners with very restricted growing space. A type suitable for autumn harvesting, since it takes 70 days to mature, is Hybrid Patio, offering medium-sized tomatoes on a plant between 24in (60cm) and 30in (75cm) high.
All these mini-tomatoes provide more fruits in proportion to the available space than the older-established varieties, but if you need a larger variety for slicing, select from Eurocross, Supercross and Moneycross, all of which are indoor cultivars.
The yellow-skinned varieties best for small-space growing are Golden Sunrise and Golden Queen. Many people harbour the suspicion that unless a tomato is red it is not ripe, but the yellow-skinned cultivars are commonly found to taste sweeter than many of the red tomatoes because they are less acid. Their skins are also much thinner.
The length of time from germination to flowering of these cultivars (unless otherwise stated) is on average about 52 days in optimum conditions. If you have the space, take the opportunity to grow more than one variety. This enables you to get to know their cultivation requirements and gives you a choice in both appearance and flavour for use in salads or cooked dishes.
Sowing tomato seed
Growing tomatoes from seed is a more economical method than growing established potted plants. It may seem that buying plants saves time and, initially, leaves more room for growing other crops, but they are generally not available until quite late in the season, whereas you can sow seed quite early in the year indoors, from early to mid spring, and control the cropping to your requirements.
Sow the seed in large, flat containers, such as the largest size of flat seed trays. Make sure these are quite clean, if you have used them previously for other plants. Use a peat-based growing medium – a proprietary brand or your own mixture – and firm the surface of the filled tray lightly. The medium should be damp but not wet. Sow the seed as thinly as possible; tomato seeds are quite large, so it is easy to space them out evenly, about lin (2.5cm) apart. (If you have difficulty handling the seeds, use a pair of tweezers.) Sprinkle a thin layer of moist growing medium over the top, just covering the seeds.
Place the seed trays in the warmest situation you can provide. A wide, sunny windowsill is ideal. Be careful where you position the trays in relation to fires and central heating appliances. An unnaturally high temperature dries out the growing medium so the seeds cannot germinate. They need only gentle warmth and moderate but steady moisture. A temperature between 60°F (16°C) and 65°F (18°C) is sufficient.
Cover the seed trays with pieces of black plastic to exclude light until germination occurs, but do not tuck in the plastic sheets at the sides. This prevents free circulation of air, encouraging mould which will destroy the seeds. Ventilation is essential.
Tomato seeds take about nine days to germinate; but there is always some individual variation, so lift the cover to see how they are progressing from about the seventh day onwards. Gradually the surface of theis disturbed by the upward thrust of the germinating shoots. As soon as the first two or three are through, remove the covering and allow the to adjust gradually to full light. Spray them very lightly with tepid water from a fine hand-spray.
The seedlings grow apace and should he watered gently as soon as the surface of the growing medium feels dry, before the seedlings show any signs of wilting. After the cotyledons or ‘seed leaves’ appear the first true leaves are produced. As soon as the plants have two or three pairs of these, they are ready to be transplanted into individual 3in (8cm) pots. At this stage they will appreciate a ‘stronger’ potting medium, such as a-based mixture with added plant nutrients.
Keep the soil well-watered, but not wet. It is useful to stand the pots on a tray of pebbles, so that excess water can drain freely out of the pots. The damp pebbles then keep the surrounding atmosphere nicely moist.
When the plants have produced sufficient growth to be transplanted into larger pots they should ideally go straight into the containers in which the plants will flower and set fruit. This shows another advantage of having chosen the small cultivars in the first place: there is no need to find space for a multitude of large pots. Pixie can be grown successfully in 5in (13cm) pots: the larger cultivars do well in 7in (17cm) pots. Hanging baskets can be planted with a single tomato plant or more than one, depending upon size: cherry tomatoes look particularly attractive trailing from a basket in a sunny window.
Site your tomato plants in the warmest and brightest location you can provide. A sunny position is half the battle, and the plants will reward you with masses of fruit.
I have been asked whether grow-bags can be recommended for tomatoes. These are very useful in a greenhouse or, but indoors are uneconomical of space. You cannot grow more than four plants in one standard-size bag-40x 15Xl5in (110x38x38cm). In a space that size you can site six 7in (18cm) pots lengthways and two pots widthways – a total of twelve plants individually potted. If your area for indoor gardening is limited, this comparison speaks for itself.
Supporting and training
The young plants should be supported with canes or tomato sticks, which need not be more than 12in (30cm) long for most of these small cultivars. When you are potting on tomatoes into their final containers, insert the canes into the growing medium before transferring the plants, to avoid damaging the roots. Tie in the plant stems immediately with garden twine or plastic-covered wire ties to keep them upright. If allowed to grow on unsupported, the stems may distort and become weakened.
Certain varieties need side-stopping, which means removing the small shoots which appear in the leaf axils. The bush cultivars, such as the trailing varieties suitable for growing in hanging baskets, do not need this treatment. You can control the overall size of the smaller cultivars by pinching out the main growing point when the plants have achieved a suitable size. This encourages them to form more trusses, so serves a dual purpose.
Fruiting and harvest
As soon as the plants reach the flowering stage they should be fed every 10 days with a balanced tomato food. The small all-female hybrid plants are self-pollinating, but if you are growing traditional varieties which would normally be pollinated outdoors by the bees, you will have to make sure that pollination takes place. A simple method of doing this is to take a fine hand-spray and lightly spray the flowers every day for a few days. This distributes the pollen from the ripe anthers, and spreading the operation over several days ensures that unripe anthers are treated as they mature.
Provide extra support for the plants as the trusses start to form, with an additional cane for each stem if necessary, as the trusses can become very heavy as the fruits ripen. From this point, feed the plants every five days; they are putting so much energy into forming fruits that they need all the nutrients they can get. Four or five trusses are as many as a single plant should be expected to produce, so pinch out any additional growing points to concentrate the plant’s energies into the existing trusses. The plant’s main growing point should be nipped out now, for the same reason, if you have not done this before.
Continue to supply water to the containers liberally as the fruits swell and ripen, particularly during the height of summer when conditions are hot and dry. Do not be tempted to increase the feed supplied to the plants in the hope of encouraging a better crop; excessive doses of fertilizer are more likely to cause the fruits to split.
You can harvest at any stage as the fruits mature, depending upon the colour and size preferred. Early harvesting encourages the plants to set more fruit, and the tomatoes will continue to ripen after picking if taken before they have fully turned red.