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How to choose tomato varieties

publication date: Feb 1, 2012
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By Andrew Mefferd

Tomatoes are the most profitable crop on many market farms — if you choose the right varieties. But with thousands of varieties on the market and hundreds of new ones introduced every year, how do you know which ones to grow? 

As the owner of a small market farm in Maine and the trial technician for tomatoes at Johnny’s Selected Seeds research farm, I have a lot of experience with growing tomatoes. I want to share my perspective on how to choose the best varieties for your location and markets.

One of the best ways to figure out what varieties to grow on your farm is to look around at the farmers and gardeners in your area and see what they like. Asking what varieties they are not growing and why will help you learn from their mistakes and not waste production space on something that doesn’t work in your area. It’s always worthwhile to keep a little bit of field space devoted to on-farm trialing of new varieties to see if they work before going into production.
Most years at Johnny’s we trial roughly 300 varieties of tomatoes in the field, 50 in the hoophouse, and 10 to 15 different rootstocks for grafted tomatoes. It is a daunting task to evaluate 400 varieties every year and figure out which ones make sense for the catalog.

The most important criteria we look at when evaluating tomatoes is flavor. It may sound redundant to say that we consider flavor with something edible, but if you’ve ever eaten a grocery store tomato, you know that much vegetable breeding is devoted to qualities besides flavor. We also look closely at yield, appearance, disease resistance, cracking, blemishes, and all the other factors that affect tomato selection.  Being a company that sells to market growers, one of the most important things for direct marketing tomatoes is good flavor since your customer will associate the flavor of your produce with you.

Before talking about individual variety selection, let’s talk tomato types. You probably already know that tomatoes are categorized by two broad plant habits: Indeterminates, which grow nearly indefinitely, adding leaves, shoots, and flowers until frost or something else kills them; and determinates, which grow more like a bush and have a predetermined size.

One reason to grow indeterminates is flavor. Generally speaking, indeterminate tomatoes have better flavor than determinates. Indeterminate tomatoes have three or more leaves between fruit clusters, whereas determinates have two or fewer leaves per fruit cluster. So indeterminates have a higher ratio of leaf area to fruit. If you think of foliage as solar panels for the sugar factory, indeterminates have a higher potential for solar panels and thus sugar and other flavor compounds.

The main reason to grow determinates is labor. Bush tomatoes have a better ratio of labor to production; it requires less labor to grow the same quantity of determinate tomatoes as indeterminate. Instead of the season-long suckering, pruning, and trellising work to keep up with indeterminates, supporting determinates with a simple trellis saves a lot of labor. We still recommend suckering and leaf removal on determinate plants up to the sucker below the first fruit cluster, mainly to improve airflow around the stem of the plant. After that, any more pruning on determinates will reduce yield and flavor by removing some of the limited number of flowers and branches. Another reason to grow determinates is for those who want a concentrated yield of tomatoes over a shorter period of time, instead of the steady, season-long yield of indeterminates. Some determinates have a single very concentrated set of tomatoes, and others may have a second set to increase and spread the yield over a slightly longer season. 

Besides the variety’s natural flavor potential, a lot of nurture goes into tomato flavor.  An average-tasting determinate might taste better than an heirloom picked off a plant that was defoliated by disease and about to die. That’s why we tend to talk about flavor and yield potential— reaching any given variety’s potential is a function of how it is grown.

Heirloom tomatoes      
One of the most diverse areas of tomato varieties are the heirlooms. Most of these are indeterminates, though not all. If you spent enough time looking at seed catalogs, you could probably find 100 varieties solely of big pink heirlooms that compare to ‘Brandywine’. You could find even more if you joined Seed Savers Exchange and looked through their yearbook of varieties that are preserved by members. Before getting into specific varieties, I must note there are so many great heirlooms that many favorites will be left out of our discussion. I apologize in advance. 

A review of heirloom varieties in general is beyond the scope of this article. I am just going to touch on a few that I think have exceptional flavor and relatively good production for fresh market sales. I would be interested to hear about your favorites if you want to send your suggestions to me. I look for heirlooms with excellent flavor, vigorous plants, and a manageable amount of blemishes so they make it to market. 

In many parts of the country, Brandywine is synonymous with good heirloom flavor. With growers, it can also be infamous for unpredictable yields and blemished fruit that is harder to sell at market. If you have a market for a big pink heirloom, it might be worth trying Rose or German Johnson (aka German Pink Johnson). In my experience, these two tomatoes have more vigorous plants and higher yield of unblemished fruit without compromising on flavor. As a market grower, I appreciate the slightly smaller fruit size of these varieties compared to Brandywine. Many of our customers at farmers markets don’t want to buy huge tomatoes that can be over $5 a fruit. In some parts of the Southeast, German Johnson has the same reputation for flavor that Brandywine has in the North. There are two strains of German Johnson; we found the normal-leaved strain to be earlier and more vigorous than Brandywine, with excellent flavor and a melting, creamy texture. 

For the “black” brown/red tomatoes with greenish shoulders, I like Cherokee Purple and Black Krim, though Krim seems to benefit from more heat than we have in the northern tier of the country. In the yellow/orange category, we have had good luck with Dr. Wyche’s Yellow, Valencia, Striped German and Gold Medal. The last two have many similarities and one may perform better in a given area than the other. The yellows and oranges are not my personal favorite. I like a tomato with a lot of acidic flavor to complement the sweetness. Yellow and orange tomatoes in general tend to be less acidic than red/pink tomatoes. But I know we have customers who prefer a milder tomato so we grow a lot of them, too. 

In the green category, Green Zebra and Cherokee Green have done well for us but there are many others. I find the green tomatoes to be less popular at market, because customers are not used to tomatoes of that color and may have doubts about their ripeness. We still grow some greens, because we wholesale mixed heirloom boxes, and they look nice with the other colors.

For heirloom sauce tomatoes, Amish Paste is as good as any of them, though there are several like Opalka that are similar. Speckled Roman, though not old enough to be an heirloom, is the stabilized cross of two other heirlooms and will one day be an heirloom due to its good looks and eating quality.

Most heirlooms do not have much disease resistance, and may be difficult to grow in areas or years with high disease pressure. One way to dramatically increase the vigor and resistance to soilborne diseases of heirloom tomatoes is to graft them onto a variety bred specifically for use as rootstock. We have seen excellent results with both Maxifort and Colosus to boost the yield and health of heirloom tomatoes. Both of them would be worth a try in your production system. Grafting tomatoes is not a simple process, but if you can learn it or buy in grafted plants, it has the potential to significantly increase yields and disease resistance without compromising the quality of the fruit. Whether in the field or the greenhouse, each leader of a double-stemmed grafted plant may perform similarly to a single-stemmed ungrafted plant.

Greenhouse/hoophouse
At the other end of the spectrum from the heirloom tomatoes with little disease resistance are the greenhouse tomatoes.  We mainly list tomatoes in the “Greenhouse” category at Johnny’s based on the variety’s ability to resist the diseases that are more likely to occur in a greenhouse. Diseases like leaf mold that are rare in the field are much more likely to occur in a greenhouse or hoophouse, especially where the lack of proper crop rotation can cause a buildup of diseases. The warm, humid conditions in a greenhouse are also great for molds and bacterial diseases. 

When we trial greenhouse tomatoes, we are looking for varieties that will do well in an unheated or minimally heated plastic-covered tunnel. This is in contrast to the high-tech, closely climate and humidity controlled facilities that many of these tomatoes were developed for. More adaptability is required to be able to thrive in the wide range of temperatures, growing mediums, ventilation, and pruning regimes that different growers have. Many varieties besides the greenhouse types are grown successfully in greenhouses, they are just more susceptible to being taken down by disease.

Rebelski is a new greenhouse beefsteak that really impressed us this past year. It hits a sweet spot between looks, flavor, and yield for protected cropping. Many of the greenhouse tomatoes we see are so highly bred for shelf life and disease resistance that they sacrifice flavor. Rebelski tastes as good as any greenhouse tomato I’ve ever had. It also has good texture when ripe, remaining firm without being hard like some commercial tomatoes. The bright red, unusually shiny appearance and lightly ribbed top are attractive and make it stand out at market. It might not be quite as heavy yielding as Geronimo but it is very productive. On the other hand, if you need very high production of a smoother beefsteak with good flavor, Geronimo might be worth a try.  If you don’t want to graft, Arbason has the most natural vigor of the greenhouse tomatoes and is a good candidate for ungrafted production, though it has less disease resistance than most greenhouse types.

We have been getting more requests for a cluster tomato, and we think that Clermon is the best tomato on the vine (TOV) that we have seen. Many customers have gotten used to seeing these types in the grocery store, and it is an opportunity for a local producer to provide a fresher, riper product than what is generally available. In cluster types, we look for varieties that ripen their fruits all at the same time. Otherwise, the first fruit to ripen closest to the plant will be mushy by the time the fruit at the end of the cluster ripens. The other thing we look for is fruits that do not easily detach from the vine, because if you want to sell a cluster of fruits they can’t fall off. Clermon does these things well in addition to looking nice and having good flavor and yield.  Clermon and most truss varieties do best pruned back to 4 or 5 fruits. If pruned to 4 the individual fruits will be slightly larger than with 5 on the truss. More than 5 fruits may not ripen together, or the sixth fruit may be undersized.

One of the best greenhouse cherry tomatoes we have seen is Sakura. It has a great combination of earliness, attractiveness, and really good flavor. In a blind taste test of greenhouse cherry tomatoes among Johnny’s staff, Sakura was the clear favorite. The crack-resistant fruits hold well after harvest.

I wouldn’t recommend growing any of these greenhouse types in the field. They tend not to be nearly as good outside of protection. If greenhouse types are the thoroughbreds of the tomato world, their racetrack is the greenhouse. You wouldn’t plow with a racehorse, and I would keep the thoroughbreds out of the field. The more labor you can put into them in the greenhouse, the more you will get out of them. The better you can keep up on a regular schedule of pruning, trellising, cluster pruning, and de-leafing below the ripening cluster, the better greenhouse tomatoes will do. 
On the other hand, many growers have great results with field varieties in the greenhouse. Our season is so short here in Maine, I have almost given up on growing indeterminates in the field. By the time they are ripening in August, it is about to start getting cool again, and we have been plagued by late blight around that time the last few years. So I have moved most of my indeterminate tomato production inside, which is split 50/50 between heirlooms and greenhouse types, all grafted. I know many people have success with determinates in greenhouses to take advantage of the reduced labor. In warmer season areas, a spring crop of determinates can be grown under cover to get on the market early, and then removed in the heat of the summer when the field tomatoes start to produce.

Field production
As far as varieties for the field go, selection must be by region in response to the diseases and pests that are in each area of the country. Indeterminate slicers Early Girl, New Girl, Big Beef and Jet Star have all been popular for years, but there are many other varieties that may taste better depending on region and season. 

As far as determinate slicers go, Polbig has unusually good flavor for a very early tomato. Celebrity has long been a popular main-season determinate. Defiant PHR is smaller than Celebrity and has the added benefit of resistance to late blight. Valley Girl, Solar Set and Floralina can do well in hot summer areas where regular daytime temperatures in the 90s can cause the blossoms to drop. Mountain Fresh Plus is one of the most popular market varieties in the East and Midwest. BHN-1021 has good flavor and nematode and tomato spotted wilt (TSWV) resistance which may help growers in much of the South. A very leafy variety like Shady Lady is popular in very sunny parts of the country where sunburn of the fruits can be a problem.   

For sauce tomatoes, we look at tomatoes with high solids and little juice in addition to good flavor. Meaty, less juicy tomatoes can be cooked into sauce much more quickly.  Sauce tomatoes are a great opportunity to grow a determinate and save on labor, since good determinate tomatoes have enough flavor and sugars to make tasty sauce. At least in my market, people don’t want sauce tomatoes early in the season, and then they want a whole bunch at once later in the season for canning and sauce. Monica, Mariana, and Roma have all been popular for determinate plum tomatoes. Plum Regal has the added benefit of late blight resistance. For markets that demand a San Marzano shape, Paisano is a high yielding bush type. If you want to grow an indeterminate, San Marzano 168 is earlier and a better yielder than most San Marzanos. In general, the longer shaped tomatoes are less prone to many common blemishes, but more susceptible to blossom end rot, so keep calcium levels optimal and watering even if you are growing these types.

In the Saladette category, we select meaty tomatoes that would be great eaten fresh in salads or on sandwiches, for fresh tomato sauce, and good processed.  For the smaller saladettes, Juliet has long been popular for its unusually healthy plant and big yields of mini-romas with good flavor. Juliet is good enough to eat fresh, and the stem scar is so small you may be able to process it without coring. Mountain Magic is a “cocktail tomato,” the size of a very big cherry, with really excellent flavor and the added benefit of late blight resistance. Granadero is a great indeterminate plum with nematode and TSWV resistance, and a great example of a versatile tomato you could eat fresh if you wanted a less juicy tomato, or make into sauce.

Growers in many areas have good luck with indeterminate cherry tomatoes BHN-624, Sun Cherry, Super Sweet 100, and Sweet Million. Sun Gold is one of the tangiest, most fantastic tasting tomatoes ever but it splits readily, so don’t over-irrigate, or pick it before a big rain! Sun Gold is an opportunity for market farmers to provide a product not available in the grocery store, since they are too delicate for shipping. Most determinate cherries are not great tasting but BHN-968 is surprisingly good, and has nematode and TSWV resistance.
The good grape tomatoes are not simply oval-shaped cherry tomatoes, but meatier, less juicy, more flavorful versions of the little round tomato. Since customers may not know this, a sign or sampling will help turn people on to the grapes. Mixed pints of cherry or grape tomatoes are appealing on the market stand.

Dry farmed tomatoes
One trend in tomato growing that is worth trying is dry farming. This practice was developed in California in response to over-irrigated, washed out tasting tomatoes.  Outdoor tomato crops are established either in the spring with natural rains, or with irrigation. Since it doesn’t rain during the summer in most parts of California, irrigation is stopped when the plants set their first flower cluster. By that time the plants are rooted enough to survive without irrigation, but the lack of any extra water means the fruits develop smaller than they normally would for the variety, and the flavors are concentrated. Dry farmed Early Girl has become a farmers market staple in California.  New Girl, Cherokee Purple, and Taxi also are used.     
 
Growers in parts of the country that get rain during the growing season are experimenting with dry-farming by establishing crops in a hoophouse with big irrigations to push the roots deep, and then turning off the irrigation once the plants are well established (after setting the first flower cluster) and letting them fend for themselves the rest of the season. Grafting can help with this practice because the plant develops a bigger, more robust root system. If you have never dry farmed before, keep the irrigation functional, in case the hoophouse gets hot or dry enough to kill the plants or give them blossom end rot. This is not an established practice outside California yet, and it may be a chance to bring something new to market. Dry-farming could probably work well with many other varieties. You could experiment with it by turning off or reducing the irrigation to just a row of tomatoes and seeing what happens.


Besides working at Johnny’s research farm, Andrew Mefferd owns One Drop Farm with his wife, Ann. He can be reached at andrew@onedropfarm.com


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