16 things i know about growing tomatoes
FROM THE FIRST SEED SOWN to the last fruit stashed in the freezer, homegrown tomatoes are a labor of love. Whether it’s tomato-sowing time (as it is April 15ish in my Northeastern Zone 5B), or maybe already transplanting time in yours, it’s a good moment to review what goes into tomato-growing success.
Don’t worry: There won’t be a quiz at the end, where instead you can also share any tomato wisdoms of your own for our collective benefit.
my 16 bits of tomato wisdom
1. Start with a homegrown seedling (grow it like this) or a locally raised one—not a big-box-store seedling that may have been shipped in from warmer zones, where more tomato diseases are endemic and overwinter. (That logic isn’t tomato-specific; I buy local seedlings or grow my own everything—especially that basil I hope to have at tomato-harvest time. Plants from far away can be vectors for disease.)
2. Getting great flavor out of a tomato is part nature, part nurture—meaning the genetics of the seed you start with, and the way you grow it both factor into what is probably a 60-40 equation. Choosing a Florida-bred variety for your New Hampshire garden will never let you hit the sweet(est) spot. Here’s why, and how to push for a perfect flavor score.
3. Growing a mix of both hybrids and open-pollinated types (including older heirlooms and newer non-hybrid varieties) may offer you the best overall insurance policy against failure. Whichever varieties you choose, read up on them first, and select not just by a pretty photo or extravagant flavor claims, but also for traits like regional adaptation, disease resistance, and days to harvest (so it’s a realistic match for your season’s length).
4. Open-pollinated tomatoes are not mass-produced, uniform widgets (nor is any other OP plant). A ‘Brandywine’ is not a ‘Brandywine’ is not a ‘Brandywine.’ With non-hybrid varieties like it, there can be great swings from seed-seller to seed-seller, based on where and how they raised the seed for generations, and what they had in mind as they selected each crop.
5. With open-pollinated tomatoes, it’s possible to save seed and get a next generation that reliably resembles the parent plant. However, careful selection—sort of a “survival of the fittest” regimen, but enforced by the gardener’s hand—is key to good seeds next time around. Therefore, seed saving begins at seed-starting time, I learned from a seed-farming friend. Sow only the biggest seeds in the packet, discarding the runts (and then discarding slow-to-germinate or weak seedlings), continuing your selection process ruthlessly at each life stage, right through to harvest.
6. Feeling daring? You can also save seed from a hybrid tomato, and try “dehybridizing” it, by selecting among its offspring next year and beyond for traits you like. Breeder-author Joseph Tychonievich talks about dehybridizing and about smart selection with OPs, too, in this story. When it’s time for harvest: how to ferment and clean harvested tomato seed.
7. With all the diseases and mechanical issues a tomato can experience, it’s a wonder we ever get a harvest—but blessedly we do, and we can even improve our odds. Most gardeners and farmers are fighting the presence of some kind of soil-borne tomato pathogen, such as the septoria and early blight that reside in Northeast, mid-Atlantic and upper Midwest soils. That means rotating tomatoes from one spot to another doesn’t cut it; we need to manage around disease presence. Start by choosing resistant varieties, and then following good tomato-hygiene, including:
8. Growing tomatoes on black plastic increases soil heat that tomatoes love; provides weed suppression, and helps with soil-splash control–keeping some of those soil-borne spores from getting up onto the plant by creating a barrier. Stripping the lower leaves from the plants to eliminate the “ladder” for spores splashing up may help as well. (Want to grow them up out of the ground, in straw bales? Here’s how, from NC Tomato Man Craig LeHoullier, who also wrote a book on straw-bale gardening.)
9. If you are worried about late blight specifically, the hygiene regimen also includes discarding any potato tubers missed at fall harvest, and these other steps. (Or: Read how a plant pathologist from Cornell grows her own backyard tomatoes with disease prevention in mind.)
10. Whether you stake or cage or trellis indeterminate varieties, think also about good air circulation to limit diseases. Never grow tomatoes trained together onto teepees or tripods; any tangle of tomatoes too closely spaced like that means a humid environment that invites more tomato troubles.
11. Be realistic: If you’re not going to prune all season, don’t stake plants; use a cage. Staking requires that each indeterminate plant be kept 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, too, on staked plants.
12. Yes, tomatoes are “heavy feeders,” but a good soil that’s high in organic matter (compost, compost, compost) is your best ally. Don’t overfeed, especially with nitrogen-rich fertilizers; it can invite trouble.
13. Sometimes, despite all the loving care, tomatoes fail to set fruit. Assuming you did not feed 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 nitrogen, or by irregular watering. Hot, dry conditions at blossom time prevents proper pollination and can causes buds or tiny fruit to drop. If it’s early enough, a next round of flowers may appear during favorable weather.
14. Nobody agrees on what the “best” tomatoes are. My friend Gayla Trail likes the dwarf types, as does Dwarf Tomato Project co-founder Craig LeHoullier (his picks are here). My farmer neighbor Max Morningstar and I agree life without ‘Juliet’ wouldn’t be as good. ‘Principe Borghese’ is often named as the go-to if you plan on making dried tomatoes (but not “the best” otherwise). The list goes on.
15. Nobody agrees on how best to ripen tomato fruit, either, if the weather turns on you late in the season. On the windowsill, or in the darkness of a paper bag, or…?
16. Don’t forget: Plant enough of at least one paste type for last-minute freezing of whole fruits. Forget canned tomatoes going forward; just pop some of those out of a freezer bag into that soup or stew or chili recipe instead. Or go one step farther, and herb and oil and pre-roast “extras” of your favorite tomatoes of any kind, then slide into freezer bags for the best “sauce” or ingredient ever. My other must-have to freeze: my easy, skins-on tomato sauce.