Top 10 Tomato Growing Tips

Provide Light for Seedlings

To maximise the growing season, start tomato seedlings off indoors on a south facing window sill in February. Because the day length is still short and the light weak, the seedlings can be drawn and leggy. To help avoid this put a piece of cardboard covered with aluminium foil behind the seed tray to reflect light back onto the seedlings.

Transplant Seedlings Quickly

Studies have revealed a strange fact about tomatoes. If sown in flats or pots and transplanted into individual pots within five days of emergence, the eventual plant will be far more productive than a plant from a seedling transplanted later.

Plant Deep

Once the seedlings have developed their true leaves, transplant on into 7.5cm pots and once they've filled those into their final position. If you look at the base of the stem you will see tiny hairs which are actually ready to develop into roots. Plant deeply, covering those hairs and up to the leaves and they will grow into extra roots providing the plant with more energy.

Sideshoot Regularly

Indeterminate varieties, those usually grown as a single stem in a cordon, will produce side shoots. These will grow and produce more foliage but we want the plant to put its energy into fruits so it's important to pinch off these side shoots as they develop. The side shoots always start at the joint between the leaf and stem.

Regular Watering

It is critical to avoid the plant becoming short of water. If it does, when eventually watered, the skins will split on the larger tomatoes and young fruits will develop a condition called blossom end rot.

Feed Well

Tomatoes produce a lot of fruits from each plant but they do need feeding properly to achieve this level of production. If using a proprietary feed, follow the instructions carefully. Do not overfeed though or the plant can develop problems.

Space Well

Avoid overcrowding plants. There's always the temptation to squeeze an extra plant or two in when greenhouse growing but this overcrowding will stop light getting to the plants and encourage pests like whitefly and fungal diseases like grey mould or botrytis.

Stop Plants

Left to itself, a cordon grown tomato will keep growing until the end of the season when it naturally dies back. This will result in lots of immature and unripe fruits at the end of the season. Once the plant has produced 5 or 6 trusses of fruits, pinch out the growing tip of the main stem to encourage those to bulk and ripen. You will end up with more fruits this way.

Second Cropping from Sideshoots

After planting out in their final place, whether border or growbag, allow a sideshoot to grow to about 15cm long before removing it. Plant this in a pot of damp or even wet compost and in a matter of days it will develop roots. These second plants can provide a follow up for when the first plants start to fade and extend the growing season.

Ripening Fruit

Ripe tomatoes release tiny quantities of ethylene gas which signals the other fruits nearby to ripen. Leaving a ripe fruit on a truss will encourage the unripe to turn. If you've got a lot of mature but still green tomatoes, put some ripe bananas in with the plants as these release relatively large amounts of ethylene gas.

Thinning out the leaves to allow more sunlight to reach the fruits will also help ripening towards the end of the season.

Copyright © John Harrison 2015