6 Critical Dos & Don’ts For Growing Tomatoes

Learning how to grow tomatoes is very rewarding. Tomato plants are often vegetable gardeners' top choice in North America as they are quite easy to grow, offer great versatility and nutrition to the North American diet, and produce an often bountiful and flavorful crop year after year. Even without much room, tomatoes can grow in small spaces, narrow plots, and containers of all sizes, making them perfect for decks, patios, or balconies.

Tomatoes grown in balcony (Source)

Tomatoes have two basic ways of growing -- determinate and indeterminate. The vines of determinate varieties grow only 1 - 3 feet long, and are often called bush tomatoes. Indeterminate varieties have sprawling vines that grow 6 - 20 feet long, producing fruit all season long. There are many varieties of tomato plants to choose from within these two categories, so be sure to choose the tomato variety that is right for you and your kitchen. Learning how to grow tomatoes can seem somewhat daunting at times considering all the varieties, so it is best to pick a variety that appeals to you and just try!

Do's & Don'ts of How to Grow Tomatoes

  • DON'T place tomatoes on a sunny windowsill to ripen; they may rot before they are ripe!

  • DON'T expose your tomato plant to heavy frost. If your tomato plant still has fruit when the first hard frost threatens, pull up the entire plant and hang it upside down in the basement or garage. Pick tomatoes as they redden.

  • DO Practice crop rotation from year to year to prevent diseases that may have over wintered.

  • DO Help tomatoes through periods of drought by placing some flat rocks next to each plant. The rocks pull up water from under the ground and keep it from evaporating into the atmosphere.

  • DO Prune plants (if using stakes or cages) by pinching off suckers so that only a couple stems are growing per stake.

  • DO Leave a few suckers on the middle and top of the plant to protect the fruit from sunscald, especially if you live in a hot, sunny area, such as in the South. Sunscald produces light gray patches of skin that are subject to disease. When the vine reaches the top of the stakes or cage, pinch back the tips to encourage more flowering and fruit.

How to Plant Tomatoes – Inside or Outside

How to Grow Tomatoes Indoors (Direct from Seed)

If you choose to grow tomatoes direct from seed, find a sunny spot indoors (such as a south-facing window) that provides 6-7 hours of sunlight and a warm, humid environment for the seedlings. If you don't have sunny windows, use a heating coil for bottom heat and a fluorescent or grow light overhead.

At 6 to 8 weeks before your area's last frost, sow seeds ¼ inch deep and 1 inch apart in well-drained flats. Seeds will germinate in about 1 week when the soil temperature is 75° to 85°F/24°C to 29°C; at 60°F/15°C the germination process can take 2 weeks. Once the seedlings emerge, keep the temperature no higher than 70°F/21°C, and water regularly. Once a week, you can feed with compost tea or fish emulsion, and discard any weak seedlings.

Water Your Tomatoes Regularly (Source)

When the second set of leaves—the first true leaves—appear, transplant to individual pots or deep containers (such as plastic cups), burying the stems deeper than they stood previously. Whatever container you use, make sure it has drainage holes in the bottom.

After this initial transplanting, give the seedlings less water and more sun. As the weather warms, harden off the plants before planting them in the garden. Again, discard any weaklings that might harbor disease.

Transplanting Tomatoes Outdoors

1. Choose a sunny spot to transplant your tomato seedlings (they need 6-7 hours of sun daily). To lessen shock, you can transplant seedlings on a cloudy day. Make the holes larger than the size of each seedling and cover the bottom of the hole with several inches of compost mixed with bonemeal. For magnesium, which promotes plant vitality and productivity, sprinkle 1 teaspoon of Epsom salts into each hole.

Note: If you plan to train your tomato plants on stakes or in cages, pound 5-7 foot stakes 6 -8 inches in the ground or insert the cages. As the vines grow on staked tomatoes, tie them loosely to the supports with twine, cloth or panty hose. Avoid disturbing the soil around seedling roots as much as possible when you set them in their composted holes.

2. Set the seedlings in the ground so that the lowest set of leaves is at soil level and fill the hole with a mixture of compost and soil or bury the stem horizontally in a shallow trench so that only the top leaves show, stripping off the leaves along the part of the stem that will be buried. Press down the soil gently but firmly to remove air pockets.

3. Space tomato plants 2 feet apart; space them half the suggested distance in warmer climates, especially if using tomato cages.

4. Give each plant about 1 gallon (about 4 litres) of WARM water (27 degrees) within ten minutes of transplanting to avoid transplant shock.

Watering & Fertilizing Tomato Plants

Give the plants at least 1 inch of water a week, keeping in mind that a deep soaking is better than several light waterings. Avoid wetting the foliage, since wet leaves are more prone to diseases.

Space watering times out more after 10 days but ensure that plants receive 1- 3 inches of water weekly depending on whether you see the soil drying out or not. If not, give each plant about 2 gallons per plant "per week", beginning around the end of the second week after transplanting. You can increase water as the plants get larger and when weather is hotter. Drip or soaker hose watering is better than overhead.

You can lay some mulch around the tomato plant five weeks after transplanting to help the plant retain moisture. A weekly dose of liquid seaweed will increase fruit production and plant health, as will side-dressing with compost two or three times during the growing season. You can also fertilize your tomato plants with a fish emulsion, two weeks prior to first harvest, and again two weeks after your first harvest.

Harvesting Tomatoes

Once your tomatoes start ripening, check the vines almost daily in order to harvest fruits at their peak. Ripe tomatoes will have even coloring and will be just a little softer than a firm tomato. Cut or gently twist off the fruits, supporting the vine at the same time to keep from damaging it.

Most plants can survive a light frost if adequately mulched, but not a heavy frost. To continue harvesting a crop, cut a few suckers from a healthy plant and root them indoors in good potting soil in 3-gallon or larger containers. 

Keep in a warm, sunny spot, and with a little luck and care, you can enjoy fresh tomatoes right through winter. It just depends on whether or not you can create such an environment.

Ripe tomatoes will keep refrigerated for several weeks, but their taste and texture will decline. Green ones will eventually ripen if kept in a warm place out of direct sunlight. To slowly ripen green tomatoes, and extend your harvest, wrap them in newspaper and place in a dark, cool area, checking frequently to make sure that none rot.

Pests & Dangers for Tomato Plants

  • Aphids
  • Flea Beetles
  • Tomato Hornworm
  • Whiteflies
  • Blossom-End Rot
  • Late Blight (a fungal disease that can strike during any part of the growing season which will cause grey, moldy spots on leaves and fruit which later turn brown.)
  • Tobacco Mosaic Virus (creates distorted leaves and causes young growth to be narrow and twisted, and the leaves become mottled with yellow.)

If you any comments about how to grow tomatoes, you can reach us from our Contact Us page. We'd also love to see pics of your awesome tomatoes!

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