Bill Thorness stakes out the best way to cultivate your growing treasures.
STORY BY BILL THORNESS
Tending tomatoes is a joyful task for an edible gardener, so let’s discuss how best to cultivate your growing treasures.
First, as you stain your fingers pungently green, realize that this paragon of summer wasn’t always so revered. As recently as the mid-1800s, tomatoes were thought to be poisonous — and not unrealistically so, as they do have toxic relatives in the nightshade family. Early gardening books and seed catalogs, if they did list tomatoes, would state just the basics: red, large, etc. No varieties or poetic language about taste.
Neither were the early tomatoes much to look at, says Craig LeHoullier, author of the definitive tomato tome, Epic Tomatoes. “Ugly, wrinkly, flat and red” is how he describes them. Once people started to get the tomato bug, though, breeders for seed companies took up the challenge of making the tomato as beautiful as it was tasty.
The tomato rainbow of colors, sizes, and flavors would come later, as would varieties bred to produce in all climates. Ironically, the heirloom revolution would bring those odd, old varieties back into vogue. Wow your friends with the accordion-shaped Costoluto Genovese, whose curled foliage has fooled many a gardener into performing last rites on the plant.
With such an unlikely story arc, our summer tomato tasks of trellising, fertilizing, watering, pruning, and harvesting take on new meaning.
We physically support tomatoes to encourage vertical growing for air circulation (to prevent fungal diseases), fruit ripening, and critter avoidance.
The best tomato trellis is the one that’s already surrounding the plant, installed early before the plant gets bushy or vining. But if you don’t have some support up yet — or if I convince you that some extra heft is needed — here are a few tips.
Tomatoes grown vertically on a trellis or stakes should be 3 feet apart and have 4 feet between rows, advises LeHoullier. If caged, the spacing should be 2 feet by 3 feet.
In your enthusiasm, are your tomato plants packed in more closely? Don’t despair. Target the center one and “pull it out with a good root ball and pot it up,” LeHoullier says. “People don’t understand how tough tomatoes are.”
Stake the plants by driving a sturdy 6- to 8-foot pole into the ground near your plant, and tie the tomato’s main stem to it.
Trellis by setting poles at each end of the tomato row, then running sturdy wire or twine horizontally between them on opposite sides, plant to plant, and adding more supporting layers as they grow. This is the “Florida weave.”
Cage the plant with a sturdy wire structure. The standard circular cage is too short and the metal too light to hold a robust, full-season vining plant, but it might be fine for a dwarf or bush variety. Many nurseries now sell larger, heavier circular cages (or a square one that folds flat), often with colorful plastic coatings.
Make your own cage by setting four 6-foot stakes around the plant, 1 foot from the stem. Pound them 2 feet into the soil, then unwrap a 4-foot welded wire mesh (available at hardware stores) around the stakes, tying or stapling it on.
Train the vines to lean on the mesh, or the cage, to open up the center of the plant.
Tomatoes are heavy feeders, but how much fertilizer depends on your existing soil fertility and whether the plant is in the ground or in a pot.
In general, using a balanced fertilizer (with the three component numbers roughly the same) every three weeks ensures good growth. If the fertilizer is granular, sprinkle it onto the soil, and then lightly scratch it in. If liquid, mix to the stated ratio and water slowly.
If you’re growing in containers, straw bales, or raised beds with limited soil, says LeHoullier, it’s a good idea to fertilize “weakly weekly.” Perhaps use one-third the recommended amount. The small amount of soil in potted plants means nutrients wash through quickly when watering.
Water consistently so the plants don’t get stressed by thirst. Uptake and evaporation vary, based on the weather, but also on whether your soil contains lots of water-holding compost (it should) and whether your site is particularly hot or well-draining.
The way you water can protect your plant from disease. Overhead watering results in the plant having wet stems and leaves, which is the perfect environment to cultivate spores of the damaging fungus that causes late blight.
Avoid that by watering at the base of the plant, taking care so that wet soil does not splash up onto the plant. Drip irrigation is ideal. Pruning off the bottom foot of leaves makes watering easier and ensures more air circulation.
Most tomatoes should be pruned, as they sprout voluminous “suckers” along the stem at every point where a leaf emerges. Leaving a few of these suckers and training them to be secondary stems is great, but leaving too many of them is a recipe for a dense, unruly mess.
Carefully snip the suckers at the junction with the stem. Do this weekly, as they develop surprisingly fast.
LeHoullier also advises “topping” the plant when the vines surpass the trellis level. This prevents fruit from forming on unsupported vines and allows more light into the plant. Late-season growth is especially pointless, as flowers forming then won’t have time to deliver mature fruit.
I sometimes place a bamboo stake outside the trellis and tie a particularly vigorous stem to it, allowing it to keep growing, but always maintaining air circulation.
LeHoullier writes that many people don’t know when to harvest tomatoes. It’s no wonder, with all the colors and types available — we have more varieties today than at any time in history. There are specific rules about each type, but he offers a good general suggestion: “harvest when they’re about half to three-quarters ripe and let them ripen in the kitchen.” They will still have that fresh-from-the-garden flavor, but you can monitor and test them easier when they’re on the counter.
This method avoids many problems. Overripe tomatoes can get watery or mealy and be most attractive to critters.
Finally, when you pull ripening fruit off the plant, you’re not just harvesting your food, you’re also potentially holding next year’s crop. Consider saving seeds of a favorite variety, especially from fruit that ripens earliest in the season. Those seeds will be genetically disposed to give you earlier fruit next year, and you’re virtually guaranteed that the early-season crop wasn’t cross-pollinated by insects.
With a bit of tender care and an appreciation for the storied history of our favorite summer garden treat, this year’s tomato crop will be the sweetest yet.
Seattle gardener Bill Thorness is camping near his Jaune Flamme, waiting for the first apricot blush to signal the true start of summer.