Seedlings in the big wide world
Getting plants you started from seed ready for outdoors is key to their success

BY SHARON PARKER

My father coddled his tomatoes the way an eccentric millionaire does exotic orchids. He ordered as many varieties of the legendary love apple as the Burpee catalog offered, or at least as many as he thought he could fit into his large suburban garden, started them from seed in peat pots in his makeshift home greenhouse, transplanted them into ever larger pots until each robust plant filled its own 6-inch red clay pot, and nestled each one into compost-enriched soil on Memorial Day weekend.

By the time I was a teenager, I had developed some interest in growing houseplants, but knew nothing of the vagaries of growing tomato plants in a hot greenhouse—in clay pots, no less (which, unlike plastic pots, wick moisture out of the soil). When my father went out of town for several days and left me in charge of watering his babies, I figured that, as with houseplants, the danger of overwatering was far greater than any risk of underwatering—and nearly killed them. Or so it seemed from his reaction when he came home to a greenhouse-full of sere (dried and withered) tomato plants.

In truth, I don’t think they had even begun to droop yet, and I remember my mother reassuring him that the plants would really be all right, that they weren’t all that dry after all; she argued on my behalf that my reasoning was sound, that I just didn’t understand the difference between the care of houseplants and growing seedlings for the garden. (I do now! Although I must confess, I’ve killed a lot houseplants over the years by forgetting to water them.)

Dad got over it and continued to mentor me as his novice gardener, and his tomato plants did go on to grace our table with their usual abundance that summer. He didn’t just grow tomatoes; he started several other plants from seed in his greenhouse: green peppers and marigolds and parsley and probably others I don’t recall.

When I started my own first vegetable garden after moving out, I got my tomato plants from Dad, of course. And I didn’t realize what a remarkable job he did with his seedlings until the year that a friend gave me some heirloom tomato plants that she had started from seed. The lanky, weak-stemmed plants with their tiny roots paled in comparison with Dad’s.

Clearly, Dad knew a thing or two about growing a seed into a robust plant that would thrive in the garden, some of which I shared in this column last month: adequate light, good air circulation, and transplanting into larger pots as the seedlings grow.

Transplanting into gradually larger pot sizes to accommodate expanding roots is a key step that, it seems to me, is often neglected by people who start seeds indoors. And this is understandable: What began as one compact and lightweight tray of tiny seedlings eventually becomes a couple dozen or more large, heavy pots. Where do you put them all? It’s something to think about when you start those seeds—better to start only a few so you can give them the space they need, regardless of how many seeds are in that packet.

The other key step, which home seed-starters don’t tend to forget (or they do so only once, and then they learn their lesson) is getting the plants used to the outdoors before planting them in the garden. Without this gradual transition to the big wide world, your plants will suffer transplant shock and may even just keel over and die.

The reasons for this may not all be obvious, so I’ll list them here: The sun is much brighter, the air colder; the ground is colder, the soil heavier; and Mother Nature’s watering methods are much harsher than anything your plants have experienced at your hands up to this point.

And this is where those big, heavy pots pose an added challenge to the dedicated seed-starter. My dad met this need by drafting his wife and four children into garden service, each of us carrying the pots two at a time out onto the slab in the morning and then back into the garage again at night. Although I think my dad was often on his own with that project, especially in the mornings. But when a storm threatened, it was all hands on deck to get those plants back into shelter as quickly as possible.

Lest this persuade you to say “forget this” and chuck the seedlings you have started thus far, allow me to offer some ways to make this essential task less daunting—enlisting the assistance of family and roommates being only one of them.

Don’t start too soon—wait until average overnight air temperatures are close to 40 degrees or so, and you won’t need to keep bringing them inside at night for more than a few days. Also, once trees have started to leaf out, you can find a spot with dappled sunlight to ease the transition to brighter light. Better still, if you can lean storm windows against the house or garage and place your pots behind them, this provides some shelter while still getting plants acclimated to outdoor conditions. I have done this in early or mid May, after about the third day of bringing plants in at night, with much success. (If you don’t have storm windows, consider getting a couple of them at the Reuse Center just for this purpose.)

The ground should be warm enough for tender plants like tomatoes and peppers about when the lilacs finish blooming and the lily-of-the valley starts, usually toward the end of May. If you don’t have any of these indicators nearby, or you’d rather plant by the calendar, figure Memorial Day weekend as safe for transplanting to the garden. Other vegetables can be started outdoors sooner than this, but tomatoes, peppers and other tender annuals need to be planted in warm soil if they are going to thrive. Tomatoes, especially, if placed in the ground too soon, will refuse to grow, and will even fall behind the ones planted later, after the ground is more to their liking. Trust Dad on this one—patience will pay off. And until that time, don’t forget to water those pots of seedlings!