How To Persuade a Tomato Plant to Give you Lotsa Fruit

My friend and regular Regular Farmer reader Simona recently received some little tomato plants as gifts, and asked for my advice on how to take care of them. Instead of writing her an email, I thought I'd share what I know about tomatoes with all of you. Tomatoes are pretty easy to grow, even in your backyard or on the porch. They're quite hardy in a lot of ways, and with a minimum of work, they'll give you lots of very nice fruits.

First, a little history: Tomatoes evolved in western South America and Central America, where the small, likely-yellow ancestors of modern fruits were part of the cuisine of the peoples of those regions. Evidence suggests that cultivation of tomato plants began as early as 500 BC! Europeans were initially skeptical that tomato fruits wouldn't poison them, because they belong to the Solanaceae (Nightshade) family of plants, some of which have poisonous fruit (horsenettle in this post is solanaceous). However, they soon embraced tomatoes as some weird new kind of eggplant (also solanaceous, but originating in India) and we've been eating pizza ever since.*

Because tomatoes came from such a warm area of the world, they like warm weather (surprise!). It's not out of the question to grow them in the cooler parts of the US, but you have to be timely about it. Getting seedlings from a farmer probably means your plants have had a good, early start. If you want to grow from seed, sow them to have your plants ready for transplanting in the ground (or setting outside) once temperatures stay pretty consistently in the 60s and 70s, even at night. That means something like mid to late June here in Boston.

To start, you need to choose your tomato variety (here's an incomplete list, just to show you how different they can be from your run-of-the-mill red-ripe tomato). Size, color, flavor, etc. are all up to your taste, but one important quality I think y'all should know about is whether a plant is determinate or indeterminate. Like the word implies, a determinate tomato (AKA bush tomato) puts out all of its fruit at once, so one day, you'll have a flush of ripe fruits, and that'll be that. Plants of a determinate variety tend to grow to the same height and produce approximately the same number of fruits.

Indeterminate plants, on the other hand, will grow as long as conditions will allow, and will continually produce new sets of fruit off of new growth. They take more management, but I prefer them because you can get a lot of fruit spaced out at manageable intervals each season. This post is more relevant to indeterminate tomatoes than determinate ones.

1. Basic germination and care of seedlings: If you're growing your tomato from seed (check out Seed Savers Exchange and High Mowing Seeds), you'll want to keep your soil warm (~75 degrees F) while your seed is germinating. I use a heat mat for germinating most seeds, especially in the spring when the space next to the window is only 50 degrees F. Once the seeds have sprouted, you can forgo the mat unless your plants are in a cool space like mine. Since my window doesn't face south, I also augment my seedlings' light exposure with one warm-spectrum and one cool-spectrum fluorescent bulb, which I keep on the plants a good 16 hours per day. Finally, I try to keep my sown seeds and young seedlings enclosed in a plastic container so as to keep the moisture in. A good way to do this is to tent plastic bags or saran wrap over pots or trays.

Seedlings in soil blocks with grow lights and reflective foil

2. Potting up: Of course, a setup like the one above is a hassle. It's much easier and more cost effective to buy tomato seedlings from your local farmer at the first market of the year. They'll only cost you four or five dollars, and they'll give you much more than that in fruit, so it's well worth it. When you go to buy, have an idea of what you want in a tomato, and the farmers will help you choose the variety that's best suited to your needs.

If you're planning to plant your tomato in your garden, you can do that at any time after about Memorial Day, as long as choose a spot that gets full sun (at least 10ish hours a day. More like 12 to 14 is good. Afternoon sun is better, if you have to choose) and is well drained. This means that the soil should contain enough sand and compost that it doesn't stay damp for more than a few days after a rain. As long as the spot isn't regularly wet, it should be okay.

A warning for my city-dwelling readers: City soils, and soils near older houses tend to contain unsafe levels of lead from old paint chips. If a soil testing lab confirms you don't have lead, go ahead and use your soil. Otherwise, use pots or build a raised bed with a mat underneath to prevent your plants from absorbing lead. NEVER FEED A CHILD FOOD THAT WAS GROWN IN LEAD-LADEN SOILS.

When you transplant your tomato, it's not a bad idea to bury a third of the plant below the new soil line. Tomatoes are good at producing roots out of their stems - if you leave a plant laying on the ground for a week or two, it will root itself to the spot. By burying the stem, you ensure that the plant has a sturdy base and a lot of roots to drink through. On a related note, tomatoes heal wounds well, too. If you ever snap the growing tip off your plant, just duct tape it in place and there's a good chance it'll reattach and heal.

Planted deep to encourage lots of roots

If you're going to grow the thing in a pot or bucket its whole life, you can put it in its final pot when it's about a foot tall or larger. I raised the tomato above in 3 containers before the final bucket. First was the little egg cup that I seeded it in, then a pint-sized cup, and then a 2-quart pot.

The life and times of Tom Ato

3. Maintenance and Monitoring: This is the key to getting a lot of good-sized fruit out of your indeterminate tomato. Indeterminates don't have an off switch, so to speak. They'll grow as long as conditions allow them to. My old employer starts hers in a heated greenhouse in January, and by September they're a good 12 to 15 feet long!

You should inspect your plant at least once a week, if not more. During the hot part of the summer, you'll need to water a potted plant on any day that it's going to be hot and sunny, so you can do a quick check at morning watering time. When you do, look for the following:

 - The first part of maintaining an indeterminate is suckering - removing suckers as they arise. A sucker is an offshoot that grows out of a node - where a leaf meets the stem. On a tomato, a leaf is composed of several leaflets and the petiole, or leaf stem, that comes directly off the main stem of the plant. Suckers will grow out of just about every node. They're basically a genetic copy of the plant that are there to act as a backup in case the main stem breaks. Having a lot of them virtually guarantees that the plant will be able to pass on its DNA.

 

The problem is that suckers take a lot of energy to grow. If you let your indeterminate tomato grow all of them, chances are the fruits will be small and not too sweet, because the tomato will have spent all its energy on vegetative growth. To encourage your plant to grow big fruits, it is best to grow only the main stem, or only one sucker in addition. Each stem is called a "leader." The tomato above had two leaders, as you can see in the following photo:

My 2012 plant had 2 leaders

The second leader is nice to have, because it will mature later than the main stem, so you'll get fruit from it a bit later in the season. It also acts as insurance in case you kill the main leader somehow. If you'd like 2 leaders, allow the lowest sucker on the plant to grow and remove the rest. Look very carefully for suckers; they can grow quite large without your knowledge if you don't inspect carefully for them. When you find one, either snap it off at the base with your fingers or use a sharp knife to cut it close to the stem.

- As indeterminate tomato plants grow, they tend to flop over under their own weight, so you'll need to stake your plant to keep it growing vertically. When you transplant your tomato into the bucket, put a pair of 6 to 8 foot wooden stakes at the edge of the bucket opposite each other. When your plant gets to be about 18 to 24 inches tall, tie a length of twine to one of the stakes about 12 inches up, wrap it around the other stake, then tie it off on the original stake. You'll end up with twine sandwiching your plant's stem, holding it upright. Repeat this every time the plant gets more than a foot taller than the last bit of twine.

I used four stakes for this plant because they were flimsy, but you get the idea.

- Pests are not common on tomato plants because of the solanum toxin they contain. However, tomato and tobacco hornworms, which are the caterpillars of two species of hawkmoth, can eat the leaves, and they do so with great relish. Just a few specimens can defoliate an entire plant. If you're squeamish, they may be tough to handle because they get huge stuffing themselves with tomato leaves. Check it out:

They can get even larger than that, too. You'll find them dangling engorged from the underside of a leaf stem. You can see how closely they match in color to the plant, so again, look very carefully. If you find one, pull it off and smoosh it. Probably don't feed it to a chicken (as fun as that is) because the toxins in the tomato leaves might make it sick. Tomato hornworms won't sting or bit you; the 'horn' at the back end is useless.

- Tomatoes like well-drained soil, but they need water, too. If yours is in the ground, you'll need to water it less than if it's in a bucket. In either case, check your plant on hot, sunny days, especially if it hasn't rained in a few days. I would water mine every day if it's hot and sunny, skipping cloudy or rainy days.

- If your plant starts to look sick or malnourished, you could have either pest or nutrient problems. Look all over the plant for signs that a bug or animal has damaged the plant. If you can't find any, it's probably a nutrient deficiency. Search the symptoms online to verify or send me photos and I'll see if I can figure out what's wrong. In general, it won't hurt to sprinkle an organic, general or tomato fertilizer in the pot two or three times per season.

4. Harvesting and Storing: A few quick notes on harvesting: You can tell a tomato is ready to harvest when the shoulders (the area around the stem) are no longer hard. Try to leave the stem and calyx attached to the fruit when you harvest to increase shelf life. To harvest a fruit, grip the crook in the stem between two fingers and bend, the stem should snap easily. Once you've harvested, store your whole fruits at room temperature, stem-side down. Be careful to follow safe practices when canning - home-stored tomatoes easily go bad.

That, my friends, is all you need to know to get some sweet tomaters out of your garden this year! I'm putting a list of supplies at the bottom of the page. Good luck and enjoy your fruits!

The Regular Farmer

Supplies:
- 3 to 5 gallon bucket per plant
- 0.5 cubic feet of soil per bucket 
- 2 Garden Stakes per bucket
- Twine
- Watering Can
- Sharp Knife
- Trowel or Small Shovel

---

*Come to think of it, what made Europeans think tomatoes were poison when eggplants were fine? Probably racism, if I had to guess. They didn't like potatoes either. Another New World solanaceous food, potatoes only caught on in Ireland because they grow really well in poor soil and provide almost all the nutrients humans need. Europeans sure loved tobacco, though! And that contains another toxin: nicotine. I guess their society was as fickle and trendy as ours is.

All photos mine except:
- Tomato Hornworm in Hand - By George Bredehoft (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons