How to Grow Tomatoes

For many gardeners, summer is all about tomatoes. And with good reason. Eating a sun-warmed tomato right from the vine is a different culinary experience than anything from a store. With several thousand tomato varieties, you’ll never get bored. Seed catalogues provide a dizzying array of options: red, yellow, pink, green, and purple; tiny ‘grape’ tomatoes to hulking, multi-pound giants; and indescribable variations in flavor and texture.




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Tomatoes fit more than exquisite taste and beauty into their jewel-tone skins. They are one of the best sources of lycopene you can find, a powerful antioxidant with additional health benefits that scientists are just starting to explore. According to this 2000 review from the Journal of American College of Nutrition, people who eat lots of lycopene from tomatoes and tomato products are at less risk of developing cancer and heart disease than their tomato-shunning peers.

Tomatoes are fun to grow and highly productive when planted in rich soil, full sun, and warm temperatures. They are also fairly resilient: at our house, they have survived snapped stems, overturned pots, minimal light, ‘sunburn’, and even hard frosts (when protected by water walls). While there are many ways to grow tomatoes,  the following methods work well in my zone 5 garden in the Intermountain West.

1. Start Seeds or Buy Tomato Plants:

To give your tomatoes a head start in the spring, start them indoors in pots and then transplant into the garden when it’s warm enough. If you’re short on time or don’t have the space in your house needed to start seeds, buy tomato plants. But if you have a month or two before your estimated last frost date and a sunny windowsill or grow light, starting your own tomatoes has a few advantages: you can choose from thousands instead of tens of tomato varieties; and you will save money, especially if you’re planting a lot of tomatoes.

If you decide to grow your own tomatoes from seed, plant them in pots 6-8 weeks before your estimated last frost date. Season-starters like water walls (see below for more details) let you put tomatoes in the ground 6-8 weeks before your estimated last frost date, so you can start your seeds 12-16 weeks before the last frost date.

I prefer pots that are 4 by 4 by 4 inches to allow plenty of room for root development (although just about anything works – I’ve used large plastic cups with slits cut along the bottom edges with success). Fill pots to an inch below the top with good quality potting soil, place your pots in a waterproof tray, and soak the soil.

Starting tomatoes inside gives them a month of two to grow before it’s warm enough for them to go outside.

Plant 2 to 3 seeds in each pot, and cover with 1/4 inch of soil. Strive to keep the soil moist but not saturated from now on. Keep the pots at room temperature or higher: tomatoes take longer to germinate and grow more slowly in cooler temperatures. The seedlings should appear in about a week. When your plants have their first true set of leaves, select the strongest seedling in each pot and weed out the others, leaving one plant in each pot.

Tomato seedlings need lots of light. South-facing windows may provide enough light (tomatoes seedlings always take over our south-facing living room window during the spring), or use grow lights positioned within a few inches of the leaves. Whenever outside temperatures are above 55 degrees F, place your seedlings outside so that they become accustomed to direct sunlight and wind. Gradually acclimate them to direct sunlight to avoid tomato ‘sunburn’.

Tomato seedlings grown in filtered light can be damaged by the sun if they are not gradually introduced to more direct sunlight. I’m often guilty of ‘sunburning’ my tomatoes (the plants eventually recover, although the damaged leaves don’t).

2. Transplant into your Garden

Prepare your garden with plenty of compost, and loosen the soil with a garden fork. Minimize pests, diseases, and nutrient deficiencies (including blossom-end rot) by planting tomatoes somewhere that they or their relatives, peppers and eggplants, didn’t grow last year. A 3- or 4-year rotation plan is ideal if your garden is large enough.

Tomatoes like warm soil, and they will die if exposed to freezing temperatures. My garden freezes until late May, so I protect my tomatoes with water walls so that I can get them into the ground a month or two early. The manufacturers recommend setting up the water walls about a week before you expect to transplant so that they have a chance to warm the soil. Then you can transplant your tomatoes 6 to 8 weeks before your expected last frost date. My tomatoes, peppers, and eggplants are currently residing in water walls, and all of them survived a recent low of 22 degrees F during which the water walls froze almost solid. Water walls work especially well inside a hoop house, but unheated hoop houses don’t provide enough frost protection for tomatoes without additional insulation like water walls.

When transplanting tomatoes (especially somewhat spindly ones), prune the lowest two pairs of leaves, lay the roots and the lower part of the stem in a shallow trench (tomato roots don’t typically grow very deep), and cover with soil. The buried portion of the stem will grow roots, resulting in a more vigorous plant.

Water Walls protect tomatoes from frost in the spring, giving them a 6-8 week head start. Leaves that stick out above the water level are still vulnerable to frost damage.

3. Water as Needed

If you get less than 1 inch of water per week, plan on supplementing your tomato plants’ water. Poke your finger into the soil periodically: if it’s damp an inch below the surface, the tomatoes don’t need water; if it’s dry, water them. I use drip irrigation in my garden to soak tomatoes’ roots while keeping the leaves dry, which decreases fungal infections.

4. Support your Plants:

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Young tomatoes, supported by twine, have plenty of room to grow.

While you can let your tomatoes grow along the ground, consider supporting them to keep their leaves dry. When tomatoes are supported, you can grow more tomatoes per plant, loose fewer tomatoes to rot, reduce fungal infections in the leaves, and plant twice as many tomato plants in the same space. According to Coleman‘s Four-Season Harvest, tomatoes trellised with twine (as described below) may be planted as close as 15 inches in one row along a 30 inch bed, while unsupported tomatoes require 30 inches between plants in a 30 inch bed.

Find out if your tomatoes are indeterminate or determinate varieties. Determinate varieties will grow to a maximum height of about 4 feet, produce all their tomatoes within a few weeks, and die. They can be well-supported in standard tomato cages.

Indeterminate varieties, including many heirlooms, produce their first tomatoes later that determinates, but they keep growing until the first frost. Indeterminate varieties can grow quite tall: our ‘Yellow Pear’ tomatoes consistently top 7 feet. Given a long enough growing season, indeterminate tomatoes easily outgrow the standard tomato cage and are best supported within extra tall cages, tied to posts, or trained to grow around twine.

Indeterminate tomato varieties often outgrow their supports by the end of summer.

Most of my tomatoes are indeterminate, and I support them with vertical twine. I sink 8 foot high steel posts into the ground every 6 feet along a tomato row and attach horizontal 2 by 4 s across the top. I tie twine to the horizontal beam and loosely tie the other end around the base of a young tomato plant, gently twisting the main stem of the tomato around the twine – no tomato tape required.

I prune the tomatoes to 2-3 stems as they grow and support each stem with twine. To prune, look along the main stem; just above each leaf stalk you usually can see a small stem starting to grow. Once you’re sure it’s a stem and not a flower cluster, pinch it off. The stems near the first flower cluster tend to be the strongest, making them the best candidates to keep growing.

After the tomato plants die, I cut the tomato stem at the bottom and the twine at the top and throw the whole thing, twine and all, into the compost pile (don’t compost tomato plants if they show signs of fungal infections).

5. Harvest and Enjoy!

20170718_101940.jpgLeave tomatoes on the vine until fully ripe and pick during the heat of the day for best flavor. If you don’t eat them right away, store at room temperature: refrigeration degrades their flavor.

If you grow more than you can eat, there are lots of options for storing tomatoes for future use. Their high acidity makes them safe for canning without a pressure cooker (according to a reputable recipe). Or freeze them whole in freezer bags to use in soups or sauces. My favorite preservation method is to slice them and dry them in a food dehydrator. I then soak them in olive oil and add them to salads or pasta dishes.

I dried these tomato slices in my food dehydrator.

Just before the first frost in the fall, harvest all of your tomatoes (including green ones) and bring them inside. Most will eventually ripen, or they can be shredded and used to make green tomato bread (despite the name, we really like this) or fried green tomatoes.

And then spend the winter drooling over seed catalogues and dreaming about the varieties that you will plant next year…

My kitchen is usually full of tomatoes (among other things) the day before the first frost.



3 Comments Add yours

  1. georgerudebusch says:

    Thanks for the discussion of determine it versus indeterminate varieties of tomatoes! I love the photo of the awesome 7 foot high tomato plants in your hoop house.

    Liked by 1 person

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