How to Grow Tomatoes from Seeds and 3 Video Tips for Success
The variety of tomato you grow will depend on your locale. If your growing season is short, as it is in the far north, you will want to choose an early variety to ensure yourself the best harvest. Early season tomatoes ripen quickly, typically being ready to pick within 4 months of sowing the seeds.
Choosing a Variety of Tomato
If you live in the deep south or another warm-climate area with humid summer nights, you'll want to grow varieties that are heat tolerant and resistant to blossom drop. Whatever your location, you'll need to grow your plants where they can receive at least 6 hours of full sunlight a day.
You will also need to consider when you want to harvest—all at once or gradually over the season. If you enjoy canning the fruit, a determinate variety is your best choice. These plants grow as a 3- to 4-foot-tall bush and set all their fruit within a few weeks. If you want to enjoy your tomatoes throughout the season, choose an indeterminate variety, which grows as a vine and needs staking. And for a little of both, consider the new semi-determinate varieties such as Sweet 'n' Neat Scarlet Improved and Orange Paruche. These plants stay small enough to grow in containers, yet keep bearing all season long.
When to Start Tomato Seeds
Tomatoes are best started indoors. This needs to be done 5 to 7 weeks before the last anticipated frost date. The seedlings can then be transplanted into your garden anywhere from 2 to 4 weeks after the last actual frost date. Call your County Extension Office to get frost information for your area.
How to Start Tomato Seeds
Park's Bio Dome seed starter is a great way to sow tomato seeds, because each Bio Sponge has a pre-drilled hole you just drop one seed into—no need to thin seedlings, no wasting of seeds! You can use either the original 60-cell Bio Dome, or our 18-cell Jumbo Bio Dome, which grows big, stocky seedlings ready to transplant right into your garden.
Place your Bio Dome in a 70- to 75-degree room, or just use a seedling heat mat to raise the temperature in the dome. You should see the first sprouts in 3 to 8 days. As soon as your sprouts are up, place the seedlings under strong light.
If you're using a potting mix, sow at a depth of 4 times the size of the seed. You can also use our convenient Jiffy Pots—Jiffy Pots are constructed entirely of lightweight, sturdy peat moss, so as the roots develop, they eventually grow right through the Jiffy Pot wall and into the garden soil.
Using grow lights for around 14 to 16 hours a day is ideal for fastest growth. Keep your seedlings just a few inches below the light so they don't "stretch" and get "leggy." If you don't have strong artificial light, a sunny window will work, too—just keep the clear dome on your Bio Dome to protect your seedlings from those chilly drafts.
Transplanting Tomato Plants
About 2 weeks before your transp
Plant date work the garden soil thoroughly, adding generous amounts of compost and about 4 pounds of fertilizer (5-10-10 is ideal) for every 100 square feet. Then cover the soil with a tarp or plastic mulch to keep the weeds from sprouting until you're ready to plant.
Ten days before transplanting, you'll need to start "hardening off" your young plants by setting them outdoors in a lightly shaded area for an hour or two. The next day, give them a longer visit outside until they remain outdoors overnight, still in their pots. Naturally, if a cold spell hits, bring them indoors again to wait for the temperature to rise.
When planting, bury the stem almost up to the lowest set of leaves, even if this means covering up several extra inches. If your plants have a long, tall, spindly stem with leaves widely spaced, you can plant them horizontally in the ground right up to the first set of leaves—the plant will root all along its stem. Just dig a long trench a few inches below the soil, lay the plant carefully into it as if you're burying it, and then gently angle the stem upwards, so that the only part showing is the very top, with at least 4 to 6 leaves above ground. Strip the underground leaves off the plant and cover up the entire length of "leggy" stem. Be careful not to bend the stem so sharply that it breaks—bank it with soil and pat the earth down firmly around it.
As soon as your tomatoes are in the ground, mulch heavily around the plants to keep weeds down and moisture in the soil. If you're growing the plants in straight rows, plastic mulch is far easier and effective than loose mulch (such as straw or pine bark).
The amount of space you need to keep between tomato plants depends on the type you're growing:
- Determinate and compact indeterminate—2 feet apart
- Indeterminate grown on stakes—18 inches apart
- Indeterminate grown in cages—3 feet apart
- Container varieties—2-gallon pot
Special Considerations
If you can keep from doing so, don't plant your tomatoes where peppers, eggplants, or tomatoes were planted the previous year. These veggies all belong to the same plant family and therefore have similar nutritional needs and are susceptible to similar diseases. Their presence one year can deplete soil of important nutrients and possibly leave remnants of diseases in leaf litter.
Do not over-fertilize your tomatoes, as this can make the plants less likely to flower. Your best bet is to use a formulation created specifically for tomatoes like Tomato AlgoFlash.
Use Kozy Coats to protect your plants from frost—they use water and sunlight to keep the air around your plants a few degrees higher.
Growing Tips for Tomatoes
- Prepare your soil in the fall. Lay in a foot or more of bio-degradable mulch—chopped-up leaves, grass clippings, pine bark, decayed vegetable compost, humus, and even newspaper all break down into the soil over time. This feeds the soil just what it likes so that when you approach it with a tiller or shovel in spring, it just needs to be turned over and mixed up a bit. Then top off the whole rich pile with a piece of plastic to keep the mulch "cooking" as long as possible into winter and to prevent all the good nutrients from running off in hard rains.
- If frost still threatens after you plant your tomatoes, or if you live in a short-season climate where late frosts are just part of spring, there are ways to keep your tomatoes going. One way is to place a tarp over the plants, weighing it down at the edges to keep it from blowing away. Be careful, however, not to lay the tarp or plastic directly on the plants. You will need to use blocks, sticks, or whatever you have available to form a tent over your tender young tomatoes. You can uncover it during the day and re-cover it at night, or leave it in place for several days and nights without damage to the plants.
- Once the fruit sets, be sure to keep the plants evenly watered until they're nearly ripe. The rule of thumb is an inch and a half a week, but if you begin the season watering more heavily, keep up the same rate. Just before the fruit ripens, taper off a bit. This will make the flavor meatier and less watery.
- Pick your tomatoes when they are full, red, and firm. Eat them fresh off the vine or store them at about 60°F. If you find yourself frantically picking the last several dozen while they're still green (to avoid an early autumn frost, for example), wrap them loosely in newspaper or a brown paper bag and store them in a cool, dark, dry place. Or count your blessings and fry them up at once.
Pests and Problems to Watch For When Growing Tomatoes
Nematodes live in the soil and destroy tomato plants from the roots. You can use chemicals to control these pests, but the easiest and most beautiful way to kill them is to plant marigolds along with your tomatoes. This lovely annual naturally eliminates these destructive parasites.
Cutworms are caterpillars that chew through the stems of tomato plants. They can be conquered by putting a Cutworm Shield around each plant at transplant time, or you can make your own from coffee cans, plastic drink bottles with both ends cut out, or cardboard paper towel and toilet paper rolls. Sink the shield at least an inch beneath the soil as well as several inches above it.
Pests or diseases can cause holes or spots on your leaves. The most likely pest culprit is the hornworm, which you can hand pick off your plants and dispose of as you see fit.
Blossom drop occurs when you have lots of flowers but no fruit. Anything from high humidity to unseasonable cold could cause this to happen. The plants must be pollinated to set fruit—you can help get the pollen up and moving by shaking the plant to loosen it up a bit.
If your tomatoes have a mark or dark scar at one end, that's blossom-end rot, and it's probably caused by a calcium deficiency or a sudden change in temperature during fruit set. All you need to do is cut off the affected part and enjoy the rest of the tomato. If it's marked all over, that's called cat-facing, and it's probably a result of transplanting too early, insufficient water, or unusually high temperatures. Again, just cut away the scarred area.
