Growing Greenhouse Tomatoes
How to grow tomatoes successfully in the greenhouse. Excellent information for first time growers.
Tomatoes are one of the easiest of vegetables to grow, especially in a greenhouse environment. Presently, with more than three hundred varieties to choose from, the gardener can grow tomatoes in many different sizes and colours, providing a diversity of options not common in many other areas of vegetable growth.
The three basic necessities for growing tomatoes are light, warmth and a good soil or potting mixture. The tomatoes should be situated somewhere in the greenhouse where they receive optimum sunlight. Now follows a step by step guide for growing tomatoes successfully in a greenhouse.
First, in order to ensure optimum light is getting into the greenhouse, the glass panels should be washed and then rinsed with a liquid soap.
Sow the seeds thinly in trays about 8 weeks before planting, usually around the beginning of March for the United Kingdom climate (the beginning of Spring). Cover the seeds with one eighth of an inch of sieved compost. Then cover the tray with glass and then newspaper. Turn the glass daily, to allow fresh air into the tray. The temperature must be kept the same throughout (about 18-20C), so a small heater may be required if the greenhouse environment is colder at this time of year
At one week the seedlings should be pricked out into small pots (3 inches) that have been filled with potting compost. Once they have grown to be about 6 inches tall (when the flowers on the first truss are opening) they can be transferred to grow bags, or if you have a natural source of soil in the greenhouse, planted in this, 18 inches apart. Either way, the best soil is that which is slightly acidic. Testing for this can be done using a soil testing kit. To increase the effectiveness of your soil, work in some compost or rotting manure. Dig out sufficient soil to plant and then a little more. Fill the extra part at the bottom with the compost.
Look out for side shoots that develop from the stem. They should be removed regularly, as they develop, because they are depriving the fruit of energy. By planting a few French Marigolds in your greenhouse you can prevent the tomatoes suffering from whitefly.
To support the plant, attach string around the stem below the lowest leaf. This string is then attached to a wire running horizontally along the roof of the greenhouse. As the plant grows upwards, twist it around the string, which acts as a guide and helps the plant grow straight. The stem can also be supported with a split cane.
Remember to water regularly, small amounts, throughout the growing season. Letting the soil dry out can have disastrous consequences, as can flooding the soil especially if you are using growbags. The soil’s moisture can be retained somewhat by mulching through the growing season.
After 10-12 weeks your tomatoes should be ripening and ready to pick. Make sure that when you pick each fruit the calyx is still attached.