Measuring Tomato Seedling Success

Reader Contribution by Ilene White Freedman
Published on May 2, 2013
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It’s time. It’s time to separate the wheat from the chaff. It’s time for tomato seedlings to stand up and be measured. Are they fit for the job?

If you start your own seedlings under grow lights or in a window, you might be asking these questions of your tomato plants in the next few weeks. You’ve grown them from seed. You’ve nurtured them, fussed over them, watered them, provided the best lighting you could offer.  Even if they’re spindley, you might be a bit attached to your little babies by now. You’ve grown them from a pup, and now its time for them to go out in the world and establish some roots. The main question: Will they do justice to your garden?

Ideal Tomato Plant Measurements

What exactly will it take for these tomato plants to do justice to your garden? Your goal is 5-8 week old plants with pencil thick stems and pencil long height. The height doesn’t matter as much as the stem thickness. This will give the jump start that tomato plants need in a relatively short growing season as we have in the eastern US, at least. With only July and August as hot enough months to produce delicious tomatoes, the plants need a jump start of a couple months of indoor or greenhouse growth. Seed packets say 8 weeks, but I know my greenhouse does the trick in 5 weeks. They would be monsters by 8 weeks. Under grow lights, I bet it’s closer to 8 weeks.

When I meet a new gardener who is also starting tomatoes from seed, I offer some unsolicited advice. It goes like this: If you are blending the two arts — the art of seed-starting with the art of gardening, you should know if you are starting your garden with a jump start or at a deficit.

Seed starting can be tricky, especially under lights. After all, trying to replicate the sun is a lot to expect from a fluorescent light bulb. The sun is a beautiful amazing tool. When I moved from starting seeds under lights to our first greenhouse, the difference was incredible. Seedlings that were stretching for the light under my fluorescents were now growing thick and stocky under nature’s perfect grow light. So if you can, find a way to utilize direct sunlight. Check the Mother Earth News blog for ideas on constructing something really cool. Or, if growing indoors under lights, work on how low you can keep that light, raising it a notch as the plants grow. Otherwise, they reach and reach, all leggy and spindly (same thing).

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