Q&A for How to Grow Tomatoes in a Greenhouse

Basil, chives, and nasturtium all make suitable companion plants for tomatoes.

You should plant tomatoes a week or two after the last frost. You can look up your average last frost date here: http://www.almanac.com/content/frost-chart-united-states

A temperature change can stop your tomato plant, especially if the variety is not well suited for your climate. Another possibility is a fertilizer problem. Make sure your plants are getting plenty of phosphorus and potassium while they are flowering, but not too much nitrogen.

Yes. Pinching off the top of the main stem will have not only the effect of stopping the plant growing taller, but gives the plant the ability to redirect more of its energy into fruit production.

It's due to a lack of nitrogen in the soil. To remedy this, harvest rainwater and use this instead of the water you've been using.

The most common cause of cat-facing in tomatoes is exposure to temperatures below 50 degrees F during flowering and fruit set. Low temperatures slow down pollination and cause the blossom to stick to the developing fruit. That prevents certain parts of the fruit from developing.

The further apart your rows are, the larger and more numerous your tomatoes will be. Roughly 18 inches (46 cm) is ideal according to one study. If your rows are closer together, just space the pots slightly farther apart within the row.

Make sure you are properly watering your plants and that they receive the ideal amount of light. Add a fertilizer to give them an extra boost of nutrition, and talk to a specialist at your local garden center if they continue to get worse.

Snap off the older leaves where they meet the stem.

Some yellowing at the bottom of a healthy plant is normal. Cut the lower leaves off within eight to 10 inches of the ground.

Tomato plants are subject to phototropism, which is a response to the availability of light. You need 14-18 hours of light for the growth stage for 4-6 weeks. then a massive drop in light to 12 hours of light for the fruiting stage, which should be about 8 weeks. Under normal light conditions you can grow two crops per year. If you choose to use commercial lights you can control growing and fruiting seasons (also with the use of chemicals to enhance growing and fruiting) and you will be able to have a maximum of four crops per year.

Sufficient regular watering, feeding regularly with a high potassium feed specially for tomatoes and plenty of sunshine all contribute. Another factor is the overall number of fruits being produced by the plant -- having fewer fruits on the plant will produce larger fruits.

If side shoots are allowed to grow and flower, the plant can and does produce tomato fruits and continues to grow along this side shoot stem, as well as your main cordon stem. The disadvantage is that the plant becomes harder to train and maintain when it has branches from the main cordon length, but the plant continues to grow in any case.

The main objective of cultivating in a greenhouse is to ensure the produce is genetically pure and free from any kind of diseases. Planting on an existing farm bed might predispose the plant to disease.

You should remove the suckers or branches to allow better air movement and light in the canopy. These suckers will have flowers and fruit and appear as normal stems if left on the plant.

The first flower cluster will appear on the main stem after 10-12 leaves have formed, and subsequent clusters will develop after every 2-3 leaves up the stem.

Tomato flowers typically hang like a bell and do not open wide. They are usually wind-pollinated, and you should see a small fruit about 10 days after pollination.

You can remove the large leaves after the fruit above the flower cluster (truss) has been harvested.

Commercial tomato greenhouse growers typically plan to pick 4-5 fruits from each truss (flower cluster) on the plant. You need to maintain optimal water, fertilizer, temperature, and pruning conditions.

Tomatoes ripen best under sunny conditions and warm temperatures. Typically, it takes about 45 days from pollination for a tomato to be ready for harvest.

Tomato varieties generally require over two months from seed germination to fruiting, with flowering occurring halfway through. Cool conditions can slow this process.

You can leave them on the vine until they are overripe and fall off.

You may have limited fruit because many flowers aborted due to high temperatures in the greenhouse. Temperatures must be below 80°F at night, or pollination is inhibited.

Tomatoes need warm temperatures and bright sunshine for development and ripening. It typically takes 45-50 days from pollination for a tomato to fully ripen.

Tomatoes typically require about 45 days from pollination to ripen, given adequate sunshine and warm temperatures.

You can cut the stem anywhere to stop it from growing, but keep in mind that side branches will continue to grow.

Your problem is called blossom end rot (BER). It is usually caused by inconsistent watering, which prevents the roots and stem from absorbing enough water to carry calcium to the developing fruit.

Tomatoes need sunshine and warm temperatures to ripen; it typically takes about 45 days from pollination to harvest.

Be sure to provide adequate ventilation with open windows, but some shade on the glass may help control greenhouse temperatures.

It is an indication that your plant has depleted the calcium in the soil. Tomatoes need calcium, especially at fruiting time.