Learning how to grow tomatoes indoors can be very rewarding. Your own organically-grown produce always tastes better than the store-bought. For an indoor garden, you will want to choose a crack-resistant variety. Not only will these tomatoes do better indoors under lights, but these varieties also tend to be the better sauce/paste tomatoes.
1Prepare a good starting soil mix. Use a standard potting soil mix with about 10% worm castings added. Standard potting soil is usually equal parts perlite, vermiculite, and sphagnum peat and is adjusted to the right PH by adding 1 teaspoon of hydrated lime for every gallon of soil mix. Ph adjusting your mix this way for tomatoes is good because the lime is a good source of calcium, which prevents blossom end rot in tomatoes later on. Moisten the initial mix little by little, using plain water and Thrive Alive B1. The mix is just right when you squeeze a handful and get a few drops out of it...but only a few. If you mix it a little too wet, just add a little dry vermiculite and remix.Ad
2Start your seeds. Start with a regular nursery tray full of your soil mix. Tomato seeds should be planted 1⁄4 inch (0.6 cm) deep, and about 8 seeds/inch. You may want to cover them for the first few days to keep them from drying out. Tomato seeds germinate best at 80 degrees, and should be mostly up in 5 to 12 days. Remove any cover you may have on them as soon as they begin popping up. The fresh sprouts should be kept 4 to 6 inches (10.2 to 15.2 cm) under a fluorescent light. The light should be kept on 18 to 24 hours a day. When they are 1 1⁄2 inches (3.8 cm) tall, carefully transplant them into their own 6 inch (15.2 cm) containers.
3Keep the tomatoes under 2 or 3 fluorescent lights for 18-24 hours daily. Feed them Maxsea 16-16-16 at this point, although they could probably use even more nitrogen (the first number). The strength of the solution is about 600 ppm, which is 1 rounded teaspoon of Maxsea/gallon. Add 10 ml/gallon Thrive Alive B1. The ideal temperatures for growth are 70-75 degrees during the day and 65-67 degrees at night. When the plants reach 12 inches (30.5 cm) or more, they may need transplanting to one gallon containers. After 6 or 8 weeks, your plants should be just about ready to begin fruiting them.
4Be familiar with how to force flowering in plants. Some tomatoes flower in 60 days and others take up to 80 days, beginning from the time you force flowering. Just as you begin this process, you want to make your final transplant into 3 gallon (11.4 L) containers. For the first two weeks, you want to feed them heavy with a 10-52-70 or similar fertilizer. Each time they need water, give them food also at 800 ppm, which would be a little over half of the recommended "full strength" on the directions. Keep in mind you are feeding them each time you water them. For the rest of the season, feed them 16-16-16 or similar at 800 ppm.
5Pollinate the flowers everyday while it is warm and humid. Ideally, the humidity will be 65 to 70 percent. Greenhouse growers usually do this between 11:30am and 12:30pm (basically noon) when these conditions occur naturally. For them, early and late day pollination often will not produce proper crops. The tomato flower consist of two parts. The male anthers will drop the pollen. The female carpels will catch the pollen. The resource link below includes pictures of both and of tomato flower pollination. Most male anthers produce their pollen on the outsides of the anthers, making it easy to release pollen into the wind for pollination. In the tomato plant, however, pollen is produced internally, as if trapped in a straw. This is the biggest problem for tomato pollination. The plant needs vibration at the right frequency, such as the buzzing of a bees wings, to dislodge and release the pollen. Take an electric toothbrush to each support truss and main branch. The more pollen to successfully fertilize the plant, the more seeds will be produced in the fruit (and therefore the meatier the tomato will be). Larger tomato growing operations should consider bees for pollination.Ad
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- Flowering plants need stronger light to grow properly developed fruit. Learn about high pressure sodium lighting if you have any doubts. Also, always use a little lime in the transplant soil to prevent blossom end rot. A dose of Cal-Mag once your tomatoes have fruit set would not be a bad idea. Finally, the vines that grow from leaf axils are called suckers, and should be pruned off throughout flowering. They suck up food that would normally be used to grow nice tomatoes. Learn below how to manipulate the light and dark periods for your crop, and in 60 to 80 days you should be enjoying some homemade spaghetti sauce yourself!
- Always keep an eye out for unwanted pests. Left unchecked in an indoor environment, garden pests can quickly get out of control. Diatomaceous earth will help with aphids and white flies.
Categories: Growing Tomatoes
In other languages:
Italiano: Come Coltivare i Pomodori in una Serra, Español: Cómo cultivar tomates en invernadero, Português: Como Cultivar Tomates em uma Estufa, Deutsch: Tomaten im Gewächshaus ziehen, Русский: выращивать помидоры в теплице
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