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April 16, 2012

Tomato Starting Time (Remember, it’s same as TAX DAY)

I have been in seed-starting mode for over 40 years. My first plant light was a humble affair, a 4’ shop light hung from the closet rod in the bedroom closet. I adjusted the height of the light with clothesline held in place by cleats. I lined the walls surrounding the plants with white paper to reflect the light. My landlady allowed me to use a tiny garden across the street, but most of my tomato plants were sold as part of a church fund-raiser. I was hooked.

Why not grow from seed planted directly in the garden soil?  In general, tropical plants like tomatoes, peppers, eggplants, tomatillos and many flowers won’t make it (fruit or flower) in our short season. Most Troy gardeners buy their plants from growers in the area. (Best to avoid “big box” seedlings, as they’re a possible source of tomato blight disease) Another benefit from buying local: you’ll find varieties that have done well in our season and climate, and types and flavors people prefer.

I have fun growing varieties I choose myself. I like to try new varieties too. Sometimes I experiment with saving my own seed from heirloom tomatoes. This season, I’m growing Fedco and Johnny’s seeds. The varieties I planted are Big Beef, Red Grape, Juliet, Paul Robeson, and Cosmonaut Volkov.

How does one grow tomatoes and other plants from seed? You will need the basics : good seed, seed-starting mix (clean, very light, air and water-retentive); containers for planting and transplanting; labels for containers, to keep straight which variety is in that row or cell, or pot, or flat , or mushroom tub. A source of gentle “bottom heat” (seedling mat) or spot that holds 80-85 degrees); good light source (fluorescent lights: I use shop lights or T-8 lights  3-6” above tops of plants) The lights need to be controlled by a timer, with on-off switch. I set mine to stay on 14 hours.  Note: You need the lights right after the seeds start to germinate. If you forget, it doesn’t take long to produce weak, “leggy” seedlings. I find it best to start the plants under the lights. If your heat source is your woodstove, or the top of a refrigerator in a warm room, it’s not as easy to position the lights directly over the seeds.

Planting the seeds. For tomatoes, start around Tax Day, April 15, or 6 to 8 weeks ahead of when you want to set them out in late May. I use after-the-last-full-moon in May as safe planting time for tender (frost-sensitive) plants in my microclimate. Pre-moisten the seed-starter mix with warm water. It should be moist but not wringing wet. Tomato seeds need to be covered with ¼ inch seed starter mix. Briefly, and gently spray with more warm water if needed. Cover with clear plastic. Most seeds won’t need watering during the germination period. Set the covered, labeled containers on the heat mat. NOTE: KEEP AWAY FROM DIRECT SUNLIGHT! Clear plastic- COVERED containers can bake and kill your plants if you set them in the sun, even briefly. This demonstrates the greenhouse effect.

The tomato seeds will start to germinate in 5-10 days, depending on the temperature and variety, and to some extent, the seed quality. After the seedlings are large enough to handle, when two “true leaves” are just starting, after the “seed leaves,” the first ones you see. You should transplant them into separate containers or into a flat about 2-3 inches apart. Many people use 2-3inch cell packs, peat pots or recycled containers with drain holes. I use an organic potting mix for this stage. Water in well, and place under lights.

Transplanting is not needed if you can thin out excess seedlings. Some growers plant just one or two seeds per cell.  I plant 3 squash/pumpkin seeds per pot or cell. Then snip off and leave just one squash or pumpkin seedling. This will give each seedling the room it needs to grow.(Note: start squash seed 4 weeks before setting out outdoors on June 2.) It’s fine to sow direct in the garden, if you prefer. Last year, I grew squash in the greenhouse in pots and set them out, and direct-seeded sunflowers. Greg sowed squash and sunflowers direct. We had plenty!

Grow them on. This means taking care to water the plants, and fertilize with weak compost tea or very weak liquid fertilizer. You needn’t fertilize if your potting mix provides some nutrition. The night temperature should be 10 degrees cooler than day temperature. Example: 65-75F day temperature and 55-65F night temperature.

Harden off.   About two weeks before setting them out, stop fertilizer, reduce watering some, and gradually expose to sunlight outdoors. Start with shade outdoors, then add just  an hour of light each day. Too much sunlight in the beginning will scald them. This involves moving your plants in and out for at least a week.

Happy Tomato Growing!

Norma Rossel is a retired Registered Seed Technologist. She worked at Johnny’s Selected Seeds for 28 years, in the seed quality assurance lab.