How to grow perfect tomatoes part 1

Posted by Todd Heft on January 5, 2012 in Vegetable & Fruit Gardening | 3 comments

How to start tomatoes from seed, transplant tomato seedlings to your garden, condition the soil, the best supports for tomatoes and the essential of mulching

Read part 2 of How to grow perfect tomatoes

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Tomatoes ripening on the vine in my organic vegetable garden

Hands down the most popular garden vegetable in the world is the tomato. It’s estimated that there are about 7500 varieties, from the Arkansas Traveler to the Zorba, in a multitude of shapes, sizes and flavors. Some tomatoes are open pollinated (OP) heirlooms whose seeds can be saved and passed down through generations and others are hybrids (F1), whose seeds, unlike heirlooms, won’t necessarily express the same traits of the parent plants.

The “perfect tomato” is a matter of taste (literally). One man’s Beefsteak is another’s Cherokee Purple. What’s the perfect tomato for you? Experiment with a few different cultivars and then stick with what you love eating and enjoy growing – nurturing a tomato from seed to harvest is half the fun. The climate in your region will play a significant role in which tomatoes grow with abandon and which bear only modest fruit.

There are many gardening techniques, tips and tricks for growing tomatoes handed down generation to generation over hundreds of years. Every gardener has their most reliable methods, but regardless of climate, cultivar and whether it’s determinate (bush-type) or indeterminate (vine-type), these guidelines will get you on your way to growing perfect tomatoes.

Know the last frost date for your area

Your last frost date is critical information and can be found at the NOAA satellite and information service. Think of the last frost date as your line in the sand – start seeds indoors 8 weeks before this date and plant seedlings outdoors shortly after this date. Where I live in Pennsylvania, the last potential frost date is May 14 and I never plant tomatoes before then. The tables are remarkably accurate-last year, the  last frost in my area was only a few days prior to the 14th.

Early set out tomato seedlings covered by milk jugs, which protect the seedlings from frost, cold nights and hungry rabbits

If you’re tempted by early warm weather in April to plant before the last frost date, make sure that seedlings are covered at night with plastic milk jugs or a similar material because even if you don’t see any more frost, cold nights and cool days can wreak havoc on exposed tomato seedlings. Gardeners using row covers or garden tunnels can plant weeks earlier, as the covers keep frost off the seedlings and add roughly ten degrees to air temperature inside the tunnel.

Starting tomatoes from seed

If you’re going to grow tomatoes from seed, start them indoors eight weeks before the last frost date in your area. After filling with potting medium, warm pots from the bottom with a heating mat. Tomato seeds like a very warm soil to germinate and although they’ll do so at room temperature, it will take two or three days longer. The goal is to get seeds to germinate as quickly as possible – a fast seed makes for a healthy seedling.

Plant seeds 1/2″ below the surface of the potting mixand use 2 or 3 seeds in each pot. Lightly water, then cover the pots with a sheet of clear plastic or a clear cover of some other sort to create a greenhouse effect.

Starting tomato seeds in fiber pots

Some gardeners prefer starting seeds in very small pots or pods and transplanting seedlings to larger containers as they grow. I’ve had better luck starting the seeds in the same containers in which the seedlings will be planted, for instance 3″ Square Peat Pots. Growing seedlings in the same container from seed through transplanting in the garden minimizes stress on the roots, which can disrupt growth or damage the seedling.

Keep pots covered with plastic until seeds germinate in six to eight days, then remove plastic to prevent mold or fungal infection. Water as needed, but don’t allow the soil surface to become dry.

When seedlings are about two inches, select the healthiest in each pot and snip off the unwanted seedlings with a Garden Snip. Do not pull unwanted plants from pots, as it may disturb the root zone of the seedling you wish to keep. Tomato seedlings need plenty of light from this point forward, so move pots under grow lights or place them in a window with southern exposure.

In northern climates, it’s not recommended that you sow seed directly in your garden bed, as the growing season is too short. In Southern climates direct seeding is okay, because the growing season is much longer.

Transplanting tomato seedlings

tomato seedling at about ten weeks

Transplant seedlings outdoors anytime after your last frost date. In Northern climates, three weeks prior to planting, cover the garden bed with Planters Paper®, SRM Red Mulch or Solar Mulch to warm the soil (warm soil stimulates root growth). Harden off seedlings two weeks prior to planting, leaving them outdoors to adjust to your local conditions, but not in direct sunlight. A covered porch which receives morning sun is ideal.

Plant seedlings when soil temps have reached 58 degrees or higher (use a Soil Thermometer) and night time temps do not drop below 45 degrees. Planters Paper, Red Mulch or Solar Mulch may be removed from the garden bed before planting, or left on to suppress weeds. Cut a 6 inch wide hole for each seedling, deep enough so at least four inches of the plant’s stem is buried in soil. This encourages deep rooting, which will protect your seedlings during a drought or heat wave.

If you’re supporting your plants with a tomato cage, wooden stake, or other device, place the seedlings 15 inches apart in a straight row down your raised bed. If you will not be supporting your plants, allow 24 inches for determinate varieties and 36 inches for indeterminate varieties.

Soil and fertilization

Use a Soil Test Kit, available at any garden center or online to determine your soil’s pH. Tomatoes prefer soil that is light, with lots of organic matter and a pH range of 5.8-7.0. They’re heavy feeders and prefer a balanced N P K organic fertilizer. Too much nitrogen, a common mistake among new gardeners, will make the plants leggy (more stem than leaves) and hinder fruit development. I always mix lots of tree leaves into the bed in fall, compost in early spring, compost again right after planting the seedlings (around the plant but not touching the stems) and then twice more throughout the season.  Supplement the compost and leaves with a feeding of fish emulsion or liquid seaweed every two to three weeks.

Supporting indeterminate tomatoes

In my experience, a tomato cage is useful for bush varieties, but useless for the long vines of indeterminate plants. Late in the season, when producing copious amounts of tomatoes, the vine will grow over the top of the cage and down the other side, creating a pinch in the vine, which will restrict fruit development. To avoid this, prune the plant to stop at the top of the cage.

Wooden Garden Stakes are the best means of support for tomatoes in a backyard garden. Tie the vine to the stakes as necessary with short pieces of fabric (wire ties cut into the stems). Make sure that you plant the stake at the same time you plant the seedling – this avoids root damage down the road. Trellising and training tomato vines overhead are quite effective as well, and are the preferred methods of commercial growers. Overhead support allows the vine to climb, but proper pruning with these methods is absolutely necessary and best left to experienced hands.

Mulching tomatoes

Mulch tomato seedlings immediately after transplanting and maintain adequate mulch levels throughout the growing season. Mulch should be two to three inches deep and come to within one inch of the stem. This keeps the roots well insulated in case of a heat wave and helps to maintain adequate moisture levels. It also helps to suppress weeds that compete with the tomato seedlings for nutrients. Keeping the mulch away from the stem helps prevent fungal buildup from excess moisture. Suggested mulch materials are grass clippings, straw, pine mulch or pine bark.

How to grow perfect tomatoes, part 2 will cover everything you need to know from transplant to harvest. It will be posted shortly

Suggested Tomato Varieties (click on links or pics for more information)

Black Krim Tomato Seeds – Russian Heirloom

Ferry-Morse Brandywine tomato seeds

Black Sea Man Tomato  - Heirloom

Cherry Tomato Sugar Sweetie Certified Organic Seeds

Ferry-Morse 3140 Organic Tomato Seeds, Beefsteak (600 Milligram Packet)

Bucks County Tomato 30 Seeds – Best Tomato 1999

Ferry-Morse 1402 Tomato Seeds, Roma (500 Milligram Packet)

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