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    Top 10 Tomato Growing Tips

    Provide Light for Tomato 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.

    greenhouse tomatoes on the vine

    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.

    Choose the Best Tomato Variety

    Indeterminate Tomatoes

    Indeterminate Tomatoes Features
    Beefsteak Large fruits, meaty texture, great for sandwiches
    Big Boy Large, firm fruits, classic tomato flavor
    Brandywine Heirloom variety, large pink fruits, rich flavor
    Sungold Small, orange cherry tomatoes, sweet flavor
    Sweet Million Small red cherry tomatoes, prolific producer
    Better Boy Disease-resistant, large fruits, good all-purpose
    Big Beef Large, meaty fruits, disease-resistant
    Juliet Small, plum-shaped fruits, crack-resistant
    Sun Sugar Small, orange cherry tomatoes, very sweet

    Determinate Tomatoes

    Determinate Tomatoes Features
    Roma Plum tomatoes, ideal for sauces and canning
    San Marzano Italian plum variety, excellent for sauces
    Celebrity Medium-sized fruits, good all-purpose tomato

    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.

    young tomato plants in pots

    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

    the best tomato varieties

    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.

    watering young tomato plants in a greenhouse

    Certainly! I'll reproduce and improve the FAQ section, adding some additional relevant questions based on the content of the article. Here's an enhanced version:

    FAQ

    Can garlic be grown in greenhouses?

    Absolutely! Greenhouse garlic cultivation is not only possible but often advantageous. The controlled environment offers protection from extreme weather, pests, and allows for better management of growing conditions, potentially leading to higher yields and healthier plants.

    What is the best month to plant garlic in a greenhouse?

    For greenhouse garlic, the ideal planting time is typically between September and November. This autumn planting allows the cloves to establish strong root systems before winter, setting the stage for robust growth and a bountiful harvest the following summer.

    Can I plant supermarket garlic in my greenhouse?

    While it's technically possible to plant supermarket garlic, it's not recommended for greenhouse cultivation. Supermarket garlic may be treated with growth inhibitors and might not be suited to UK growing conditions. For best results, use garlic bulbs specifically sold for planting, which are disease-free and adapted to local conditions.

    Can you grow garlic outside in the UK?

    Yes, garlic can be grown outdoors in the UK. However, greenhouse cultivation offers more control over growing conditions, potentially resulting in a better harvest, especially in areas with harsh winters or wet springs. Greenhouse growing also allows for earlier planting and harvesting.

    How long does it take to grow garlic in a greenhouse?

    Garlic typically takes about 8-9 months from planting to harvest when grown in a greenhouse. Planting in autumn (September-November) usually results in a harvest the following summer (June-August), depending on the variety and specific growing conditions.

    Do I need to vernalize garlic when growing it in a greenhouse?

    Most garlic varieties, especially hardneck types, benefit from a period of cold temperatures (vernalization) to produce bulbs. In a greenhouse, you may need to artificially create these conditions by exposing the planted cloves to temperatures between 0-10°C (32-50°F) for 6-8 weeks. This can be achieved by careful temperature control or by using a cold frame within your greenhouse.

    How often should I water greenhouse garlic?

    Greenhouse garlic prefers consistent moisture but can't tolerate waterlogged soil. Water deeply but infrequently, allowing the top inch of soil to dry out between waterings. This encourages deeper root growth and helps prevent fungal diseases. The exact frequency will depend on your greenhouse conditions, but typically, watering once a week is sufficient.

    What are the main pests and diseases to watch out for when growing garlic in a greenhouse?

    While greenhouses offer some protection, garlic can still be affected by pests and diseases. Common issues include thrips, onion flies, and nematodes. Fungal diseases like white rot and rust can also occur. Regular inspection, good hygiene practices, and proper ventilation are key to preventing and managing these problems.

    Copyright © John Harrison 2015

    Growing Plants

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