Growing Tomatoes From Seed
Printer Friendly VersionWhy Start Early
Tomatoes are heat-loving plants that need a long warm growing period to grow from seed to fruit. Except in the most tropical areas, all U.S. summers are too short for them to complete their fruiting cycles before summer's end if started directly in the ground, since seeds won't germinate until frosts have ended and weather warms up. We need to give plants a critical headstart by germinating and growing seedlings in the warm indoors in early spring. Then when it warms up outdoors in late spring, we can plant out sturdy, well-established seedlings to bear fruit before cold weather sets in.
When To Sow Seed IndoorsGenerally, the time to start your seeds is about 6- 8 weeks before the last expected spring frost date in your area, planting the seedlings outdoors about 2 weeks after that date. Another way to figure is to plan on setting out sturdy seedlings in the garden when night temperatures stay in the mid-50 degree range both day and night. Count back and sow seeds 6 to 8 weeks before that date normally arrives. If you don't feel confident about timing, consult an experienced gardening friend, or ask at a good garden center or seek the advice of your local Master Gardener program. (Click here for a Master Gardener State Coordinator list.)
Getting Started Your planting containers should be at least three inches deep, with small holes for drainage. Use plastic yogurt or cottage cheese containers, 3 or 4 inch plastic plant pots or half-gallon milk cartons cut lengthwise, all with drainage holes punched in the bottoms. I don't recommend reusing egg cartons or old nursery packs as they don't hold enough soil volume and dry out too easily. Buy and use a good quality seed starting mix, available from any good nursery or garden center. (Ordinary garden soil is not a good choice - it often contains weed seeds and fungus organisms and it compacts far too easily.) Seed starting mixes are sterile and blended to be light and porous so your fragile seedlings get both the moisture and oxygen they need to thrive. |
See All Tomatoes
Try these great recipes from  Chunky Green and Red Sauce |
Germinating and Growing
Tomatoes need warm 75 to 85 degree conditions to start germinating. Put the containers in a warm place where they'll get bottom heat like on top of the water heater or refrigerator or use a fluorescent shop light suspended just 1 or 2 inches above the container and it will provide warmth . Keep the container moist, but not soggy. You can cover it with plastic wrap or an old piece of rigid clear plastic to conserve moisture if you like, but be sure to pull it up to check daily to be sure they aren't drying out. Water as necessary with a very gentle spray of water. If container should get too dry, you'll need to set it in a pan of water so it can soak up water again from below. Expect germination to take 5 to 10 days. Don't keep your containers in the windowsill during the germination period; cold air at night will affect germination. Check often!
Just as soon as any baby seedlings begin to emerge above the soil level, it's critical to give them light right away. Remove any covering immediately and provide a strong light source. While a south-facing windowsill is traditional, it's far from ideal, and dimly-lit plants become tall and spindly. I like to start my containers from the beginning under grow lights or a simple fluorescent shop light suspended from chains so I can move the lights up as the plants grow. The fluorescent lights under your kitchen counter will work very well for this. Raise your flats closer to them (4" to 5") with some bricks or fat cookbooks. Tomato seedlings grow best in the 65-75 degree temperature range.
Pricking Out and Potting Up
When seedlings are 2 to 3 inches tall and have several sets of true leaves, it's time to move them to deeper containers or individual pots so they have room to grow. Fill the new containers with pre-moistened mix. With the help of a fork thrust to the bottom, lift the seedlings gently from your germinating container. Try to get all the roots and disturb them as little as possible. Make a planting hole in the new container and nestle the seedling into its new home a little deeper than it was originally. If your tomato plants are spindly with long stems, you can actually bury the stems right up to the topmost cluster of leaves and new roots will grow along the buried stems. Gently press the mix around the transplanted seedlings and water them gently to settle the soil. Now is the time to begin feeding your plants once a week because starting mixes contain little if any plant food and the seedlings will have used up the entire stored food source available in its mother seed. Use a good liquid fertilizer or fish emulsion diluted to half normal recommended strength. Continue to give your rapidly growing seedlings as much light as possible and rotate them regularly so they grow evenly and don't lean in one direction.
Planting Seedlings in the Garden
In 3 or 4 weeks, or when the weather outdoors has warmed into the 50 degree range at night, it's time to "harden off" or gradually over 4 to 6 days to acclimate your seedlings to outdoor conditions. Put them outside in a protected shady spot for a half day at first, then 2 or 3 full days, then gradually move them into full sun, starting with mornings then all day long. Plan to transplant into the garden in the late afternoon or on a hazy or cloudy day to minimize stress. Set them about 3 feet apart in the garden into rich well-amended soil in full sun. Tomato plants can be buried several inches deeper than they were planted in their containers. Firm the soil around the plants and water well. Set in stakes or cages for tall-growing tomatoes at planting time. Keep your young plants moist but not soggy. I like to mulch them with a good thick layer of compost, well-aged manure, straw or other organic material. This will provide the even moisture balance needed for healthy, disease-free growth and early big fruit sets, and will also discourage weeds.
When To Sow Seed IndoorsGenerally, the time to start your seeds is about 6- 8 weeks before the last expected spring frost date in your area, planting the seedlings outdoors about 2 weeks after that date. Another way to figure is to plan on setting out sturdy seedlings in the garden when night temperatures stay in the mid-50 degree range both day and night. Count back and sow seeds 6 to 8 weeks before that date normally arrives. If you don't feel confident about timing, consult an experienced gardening friend, or ask at a good garden center or seek the advice of your local Master Gardener program. (Click here for a Master Gardener State Coordinator list.)
Getting StartedYour planting containers should be at least three inches deep, with small holes for drainage. Use plastic yogurt or cottage cheese containers, 3 or 4 inch plastic plant pots or half-gallon milk cartons cut lengthwise, all with drainage holes punched in the bottoms. I don't recommend reusing egg cartons or old nursery packs as they don't hold enough soil volume and dry out too easily. Buy and use a good quality seed starting mix, available from any good nursery or garden center. (Ordinary garden soil is not a good choice - it often contains weed seeds and fungus organisms and it compacts far too easily.) Seed starting mixes are sterile and blended to be light and porous so your fragile seedlings get both the moisture and oxygen they need to thrive. |
See All Tomatoes
Try these great recipes from Chunky Green and Red Sauce |
Germinating and Growing
Tomatoes need warm 75 to 85 degree conditions to start germinating. Put the containers in a warm place where they'll get bottom heat like on top of the water heater or refrigerator or use a fluorescent shop light suspended just 1 or 2 inches above the container and it will provide warmth . Keep the container moist, but not soggy. You can cover it with plastic wrap or an old piece of rigid clear plastic to conserve moisture if you like, but be sure to pull it up to check daily to be sure they aren't drying out. Water as necessary with a very gentle spray of water. If container should get too dry, you'll need to set it in a pan of water so it can soak up water again from below. Expect germination to take 5 to 10 days. Don't keep your containers in the windowsill during the germination period; cold air at night will affect germination. Check often!
Just as soon as any baby seedlings begin to emerge above the soil level, it's critical to give them light right away. Remove any covering immediately and provide a strong light source. While a south-facing windowsill is traditional, it's far from ideal, and dimly-lit plants become tall and spindly. I like to start my containers from the beginning under grow lights or a simple fluorescent shop light suspended from chains so I can move the lights up as the plants grow. The fluorescent lights under your kitchen counter will work very well for this. Raise your flats closer to them (4" to 5") with some bricks or fat cookbooks. Tomato seedlings grow best in the 65-75 degree temperature range.
Pricking Out and Potting Up
When seedlings are 2 to 3 inches tall and have several sets of true leaves, it's time to move them to deeper containers or individual pots so they have room to grow. Fill the new containers with pre-moistened mix. With the help of a fork thrust to the bottom, lift the seedlings gently from your germinating container. Try to get all the roots and disturb them as little as possible. Make a planting hole in the new container and nestle the seedling into its new home a little deeper than it was originally. If your tomato plants are spindly with long stems, you can actually bury the stems right up to the topmost cluster of leaves and new roots will grow along the buried stems. Gently press the mix around the transplanted seedlings and water them gently to settle the soil. Now is the time to begin feeding your plants once a week because starting mixes contain little if any plant food and the seedlings will have used up the entire stored food source available in its mother seed. Use a good liquid fertilizer or fish emulsion diluted to half normal recommended strength. Continue to give your rapidly growing seedlings as much light as possible and rotate them regularly so they grow evenly and don't lean in one direction.
Planting Seedlings in the Garden
In 3 or 4 weeks, or when the weather outdoors has warmed into the 50 degree range at night, it's time to "harden off" or gradually over 4 to 6 days to acclimate your seedlings to outdoor conditions. Put them outside in a protected shady spot for a half day at first, then 2 or 3 full days, then gradually move them into full sun, starting with mornings then all day long. Plan to transplant into the garden in the late afternoon or on a hazy or cloudy day to minimize stress. Set them about 3 feet apart in the garden into rich well-amended soil in full sun. Tomato plants can be buried several inches deeper than they were planted in their containers. Firm the soil around the plants and water well. Set in stakes or cages for tall-growing tomatoes at planting time. Keep your young plants moist but not soggy. I like to mulch them with a good thick layer of compost, well-aged manure, straw or other organic material. This will provide the even moisture balance needed for healthy, disease-free growth and early big fruit sets, and will also discourage weeds.