growing a better tomato, seed to harvest
IT’S TAX TIME THIS WEEK, THE DATE IN MY AREA to start tomatoes indoors from seed for their toasty-warm six-week headstart. As my friend Andrew says, might as well do something fun on April 15, something that pays you a return. For those just sowing now, a detailed refresher course on how…for those transplanting or doing it soon, all the other tips you’ll need to grow great tomatoes this year:
Start with dark green, stout transplants equally high and wide, preferably about 4 inches in each direction. (My step-by-step for growing your own includes many tricks; you can also shop locally for seedlings or by mail.)
Plan to grow a mix of heirlooms and hybrids for a little insurance: Heirlooms are beautiful, delicious and a critical part of our genetic heritage, but sometimes they lack the disease-resistance (often labeled VFN) of hybrids. I like to mix it up.
Remember that even with hybrids rated as having VFN resistance, the word “resistance” is the operative phrase. It means less-susceptible, not immune. There is no substitute for good cultural practices, whatever variety you begin with.
Identify a full-sun spot outdoors where your tomatoes will grow. Now pick another such spot, and preferably a third. You will need more than one area for tomatoes, since crop rotation is one of the key lines of defense against tomato various diseases that can overwinter in the soil. (No other Solanaceous cousins, no potatoes, eggplants, peppers or tomatillos, can go there in the off years, either.)
While your transplants shape up, prepare the soil: Start with a soil test, or at least a simple pH test. Tomatoes like a pH of about 6.5 (6.0-6.5 or so is fine). In acidic soils like mine, the addition of lime is recommended, at the rate of 5-10 pounds per 100 square feet worked into the top 6 or so inches.
High-quality finished compost is the best amendment you can add to support great tomatoes. Work in a 2-to-3-inch layer each year.
An all-natural organic fertilizer that’s balanced or has a slightly higher middle number (not one high in Nitrogen) can also be incorporated according to package directions.
Decide how you will support the plants, to keep them up off the ground, for best health.
Staked plants will ripen faster crops of generally larger fruit. Stakes must be at least 1 inch thick and 6 feet high, inserted a foot into the ground. Remember: Staked plants require a commitment to ongoing pruning, keeping the plant to one or two main stems of vine-like, not bush, habit. All small suckers that develop in the crotches between the leaves and the main stem must be removed. I do not have the energy for this, so I cage my plants, but here’s the encyclopedia of tomato-pruning if you wish to stake (or trellis) and prune.
Caged plants are easier to care for, and in the longterm may produce heavier yields (because they have more branches and stems). I bought myself a set of lifetime cages that also fold; you can make excellent cages from concrete reinforcing wire (6 feet of it makes a 22-inch cage). Stabilize each cage with a stake and twist-ties, unless the cage has inground legs.
Another advantage of cages: You can use them as mini-greenhouses should late or early frosts come, by having clamps and reusable pieces of clear, heavy plastic cut to wrap each cage. Some expert growers always put the plastic on in the first weeks to reduce negative effects of wind on young plants.
Harden off your transplants over the last week in your indoor care with daily trips outside to enjoy a taste of what’s to come, returning them to a protected place at night.
After all danger of frost is past, it’s planting time. Hurrying doesn’t help, and it can hurt.
Plant deep, at least to the level of the original seed leaves, or even to the topmost couple of pairs of leaves. (More on how, and how deep, here.) Water in well, applying first of two doses of liquid feed; see below under “Douse each plant’s root zone,” for details.
Space plants at least 2 feet apart in each direction; 3 or more would be much better, as air circulation is another disease-preventive tactic. Caged plants need wider spacing than staked, and indeterminate varieties more than some determinate; plan accordingly.
High-quality woven polypropylene landscape fabric, such as is used on greenhouse floors, is an excellent, porous, weed-preventive measure. It can be reused for many years. Staple it to the ground with earth staples.
On top of that, a layer of clean straw or some other organic mulch will further reduce splashing of spores and other woes up from the soil onto the plants.
Snip off any flowerbuds that set until the plant is settled in and growing strong, after it reaches perhaps a foot tall or so.
Tomatoes will rely on you to team up with the heavens and provide consistent moisture, consistent being key here. Ideal is the equivalent of an inch of water throughout the entire growing area; half again as much in the heat of summer. Remember: an inch of rain (which is what you are simulating) is a lot of rain, and takes a long time to apply. Use soaker hoses or a drip system, not the end of a hose. If you must use a sprinkler, use it in the morning, so that foliage can dry by day, and don’t work in the garden while the foliage is damp.
Douse each plant’s root zone with a liquid feed twice during the growing season. Some growers swear by doing this at transplant time and again when the first flowers appear; others say transplant and first fruit. Just remember to do it while they are in their run-up to adulthood and you will be fine. Powdered seaweed fertilizer or fish emulsion diluted in water according to label directions are two non-chemical possibilities.
Be vigilant about watching for tomato hornworms and their telltale droppings or first signs of their chewing damage. The droppings are easier to see than the green caterpillars, who normally start their eating at the tops of plants. Pick them off and destroy them.
Sometimes, despite all this love, tomatoes fail to set fruit. Assuming you did not give the plant too much Nitrogen, it may be weather-related: Nighttime temperatures that remain above 70 or temperatures below 50ish interfere with pollination. Fruit set can also be hampered by over-feeding with Nitrogen or by irregular watering.
And then there are the other tomato mysteries: cracked fruit, green shoulders on fruit, black spots on one end or the other. Here’s the scoop on what might ail you later this growing season (though the chances are greatly reduced if you followed all the tips above).
And one more thing: Please, don’t grow your tomatoes upside-down, as is the fashion started by at least one recent gimmick product. Yes, they’ll grow if you follow the instructions, but why would you bother, why spend the money? The tomato experts at Rutgers agree with me on this one, by the way. I think there’s enough upside-down in the world without us adding to the dizzying picture, no?