Neil Sperry

Neil Sperry: It’s time for tomatoes

Many nurseries sell small cages for tomatoes, but healthy tomato plants will outgrow them. Larger cages are best.
Many nurseries sell small cages for tomatoes, but healthy tomato plants will outgrow them. Larger cages are best. Photo courtesy of Neil Sperry

With so much climatic drama during the past month, you may have forgotten that it’s finally time to think about tomatoes and other warm-season vegetables.

The average date of the last killing freeze passed by several days ago, and the next few days will be the best of all planting times. I’ll leave beans, cucumbers, squash, corn, peppers and the others up to you. They don’t inspire a fraction of the amount of gardening questions that tomatoes do.

So, it seems appropriate to zoom in this week on the ever-popular tomato, the most beloved of all vegetable crops.

Garden locations

Tomatoes must have full sun. Oh, a couple of hours of shade in mid-afternoon will be tolerable, but that’s “a couple” — as in “two.” Too much shade spells doom to the yield.

Soil solutions

Most North Texas soils need amendments if you’re going to grow tomatoes successfully.

Add several inches of organic matter, preferably a combination of sphagnum peat moss, compost, rotted manure and finely ground pine bark mulch.

If you’re amending a clay soil, include 1 inch of expanded shale as well, then rototill to a depth of 12 to 15 inches. This is pretty much non-negotiable, because if you don’t prepare the planting bed properly, your tomatoes won’t prosper.


Read this part carefully. Large-fruiting tomato varieties are losers in our North Texas climate.

Big Boy, Beefsteak, Whopper and the other burger-sized slicers do not set fruit when temperatures climb above 90 degrees. You’ll be lucky if you get more than four or five fruit per plant from them. Many of the heirloom tomatoes are similarly unsuccessful.

What, then, are the best varieties? Tycoon, Celebrity and Super Fantastic are best from the mid-sized types, and small-fruiting varieties such as Sweet 100 and its offspring, Red Cherry, Yellow Pear, Porter, Roma and others rank high.

They’ll start setting fruit early, and they’ll produce well into the summer.

Buying the transplants

The plants I’m seeing in many nurseries have been there for a week or so, and some are getting a little bit leggy. As long as they’re “hardened” to the weather, being a bit tall is of no concern.

You want plants that have been exposed to cool weather and wind. They’ll probably have reddened stems.

If you find transplants that match that description, and if they’re a little bit lanky, dig a shallow trench and lay them in at 45-degree angles. They will sprout roots along their stems, and they’ll be stronger and more vigorous for your effort. Do not dig deep holes and bury their stems straight down.

Caging the plants

We’ve known for many years that you get the maximum yield from your tomato plants if you grow them in cages. However, many of the cages found in stores will be tiny things designed for tomatoes in short northern growing seasons.

Here in Texas, our cages need to be 48 inches tall and 16 or 18 inches in diameter. Don’t make the do-it-yourselfer mistake constructing your own cages out of chicken wire. Yes, they contain the plants perfectly, but you’ll have no way to harvest the fruit.

Allow your plants to produce all the branches (“suckers”) you want, but keep all of the new shoots pushed back within the support of the cages.

Texas A&M also strongly recommends wrapping the cages with frost cloth. Besides protecting the plants from late cold snaps, this will give the plants warmer conditions and a faster start growing.

Frost cloth will also lessen wind damage, and insects have a harder time finding the plants, too.

Fertilizer know-how

Our native North Texas soils have excessive amounts of phosphorus. That’s the middle number of the three-number fertilizer analysis found on all plant food labels.

However, I must confess that when I saw the first soil test report from Texas A&M that recommended adding just nitrogen to a tomato grower’s garden — about a decade ago — I thought the soil testing lab’s equipment must have blown a fuse. After all, serious gardeners know that phosphorus promotes flowers and fruit, while nitrogen stimulates leaf and stem growth. So how could nitrogen be the only nutrient recommended for a tomato plot?

I investigated further and eventually became a believer after seeing several more reports with consistent findings. Years later, I’m living proof (or, actually, my tomato garden is) that nitrogen-only plant foods, when called for, produce fabulous results.

Container plantings

No story on growing tomatoes would be complete without mentioning patio pots.

They’re a quick and easy way to grow plants where you might not have access to a plot of actual ground. Remember again, though, that tomatoes must have full sun. Many apartment and town house patios are partially shaded.

Also, use large containers. True 5-gallon pots are a minimum, but I use 7- and 10-gallon nursery pots for my plants.

Also, I buy the lightest, best potting soil I can find, and I use a diluted, water-soluble, high-nitrogen fertilizer each time that I water them.