The Big Idea Behind Dwarf Tomatoes

1 / 8
2 / 8
3 / 8
4 / 8
5 / 8
6 / 8
7 / 8
8 / 8

 

Patrina Nuske Small, co-leader of the Dwarf Tomato Project, holds some of the fruits of her labor. Photo by Patrina Nuske Small.

In 2005, the Dwarf Tomato Project was catalyzed by a long-distance friendship, curiosity, a gaping need, and an idea from an old seed catalog. Now, 90 newly created, stable, open-pollinated tomatoes are available from an ever-increasing array of forward-thinking seed companies, and the Dwarf Tomato Project — representing hundreds of volunteer gardeners the world over — can take a deep breath and be satisfied with its accomplishments.

Defining a Dwarf Tomato

Prior to 2010, when the first cultivars from our project were released, dwarf tomatoes were the most obscure members of the tomato family. Representing a third major growth habit, they combine the most useful qualities of their better-known relatives: indeterminate and determinate types. It’s important to realize that the term “dwarf” describes the relative height of the mature plant, not the size of the tomatoes on the plants.


This is fruit from the dwarf tomato cultivar ‘Uluru Ochre.’ Photo by fruitionseeds.com.

Indeterminate tomatoesare the unruly characters in the tomato world that grow up and out (if unpruned), requiring a strategy of caging and staking to keep them under control. The vast majority of tomatoes are indeterminate in growth habit, and virtually all of the popular, colorful, flavorful heirlooms reside in this category. The main benefits of growing indeterminate plants include incredible diversity (several thousand named cultivars); supreme flavor potential; and a long fruiting season that lasts until frost, disease, or a marauding critter kills the plant. Such popular cultivars as ‘Brandywine’ and ‘Cherokee Purple’ are indeterminate in growth habit.

Determinate tomatoes look identical to indeterminate types until they reach a height of 3 to 4 feet, when they explode in a mass of flowers. The tomatoes appear and ripen in vast quantity over a short period of time. The plant is then pretty well finished. Determinate tomatoes are perfect for smaller containers (a 5-gallon pot is the smallest I would use) and short cages. Because the gene for determinate growth didn’t arise until the early 1920s, far fewer determinate heirlooms exist (a few being ‘Southern Night’ and ‘Sophie’s Choice’). Many of the newer hybrids created for large-scale commercial tomato production are determinate, because they’re easier to manage in the field and appropriate for machine harvest. ‘Roma’ is a perfect example of a determinate tomato — high yielding, ripening over a short period of time, and more useful for making sauces than fresh eating. Determinate tomatoes generally don’t have the flavor intensity of indeterminate cultivars.

Dwarf tomatoes first appeared in American seed catalogs in the 1850s with the French cultivar ‘Tomato de Laye.’ A few others were derived from it, such as ‘Dwarf Champion,’ ‘Golden Dwarf Champion,’ and ‘Dwarf Stone.’ However, little further development seems to have been done, because they weren’t large-fruited or deemed sufficiently prolific. Additionally, a vast array of colorful heirloom tomatoes to use as breeding partners simply wasn’t available until fairly recently (we owe a great debt of gratitude to Seed Savers Exchange, which began in 1975, for our ability to grow so many wonderful heirlooms today). A more recent dwarf cultivar, ‘Lime Green Salad,’ appeared in the 1970s.

Dwarf tomatoes look distinct from the very start, with stocky seedlings at half the height of indeterminate and determinate cultivars. The central stalk is thicker, and the foliage is darker green and crinkly looking (this type of foliage is referred to as “rugose”). They possess the restricted vertical growth rate of determinate tomatoes, but flower and fruit until season’s end. I consider dwarf cultivars essentially indeterminate cultivars that grow vertically at half the rate of standard indeterminate tomatoes. At season’s end, if your ‘Cherokee Purple’ reaches 8 feet in height, a dwarf cultivar will be roughly 4 feet in height. As for flavor potential, as our project has discovered, the sky is the limit, and we’ve released cultivars with flavor equal to the very best-tasting tomatoes.


A variety of dwarf tomatoes grow in containers and bags in author Craig LeHoullier’s driveway. Photo by Craig LeHoullier.

The Purpose of the Project

For years, my wife and I have been selling seedlings locally. Over the last decade, as more people have been discovering the joy of gardening and the desire to take advantage of the sunny spots in their yards, interest in container and straw bale gardening has been skyrocketing. Essentially, our project was borne of the question, “What do you have that’ll do well in pots, is easier to control, and tastes great?” We now have 90 answers to that question — and counting!

Armed with a tangible reason to do the project, an additional trigger was curiosity — some of us who garden wish to go beyond what’s available and set out to create new things by using basic plant genetics. I’m fortunate to have met an Australian gardener, our project co-leader Patrina Nuske Small, over the GardenWeb online discussion board. Patrina loved the idea of creating interesting and valuable dwarf tomato plants. She also had a knack for crossing cultivars, creating new hybrids that formed the basis for our project.


This is fruit from the dwarf tomato cultivar ‘Sarandipity.’ Photo by Craig LeHoullier.

Finally, a look at a 1915 seed catalog from the Isbell Seed Company described a then-new tomato called ‘New Big Dwarf’ — large tomatoes on a dwarf plant. The catalog described how they managed this breakthrough; they crossed one of the existing smaller-fruited dwarf cultivars, ‘Dwarf Champion,’ with the largest-fruited tomato of its day, ‘Ponderosa.’ After generations of selection work, they succeeded in creating a dwarf-growing cultivar that had fruit nearly as large as ‘Ponderosa,’ approaching 1 pound. I actually found this obscure cultivar sitting in the USDA seed collection, obtained some seeds, and was delighted to find that I could confirm Isbell’s success. Having the ‘New Big Dwarf’ seeds also meant we had an additional cultivar to use as a breeding partner.

How the Project Works

Patrina and I had a goal, a small set of existing dwarf tomatoes, and a plethora of colorful, flavorful heirlooms. Patrina had the skill to make the crosses to create the starting hybrids. We even had two different growing seasons per calendar year because, when we began, it was possible to share seeds between the United States and Australia (sadly, this is no longer the case). All we needed at that point was a team of willing volunteers. The main qualities we were seeking included curiosity, willingness to share, openness with information, and agreements to keep saved seeds in the project and share information on a newly created online discussion board, www.Tomatoville.com.

Patrina made an initial set of crosses and decided to use Disney dwarf names for each new hybrid, creating a “family” to work with. For example, we crossed the wonderfully delicious indeterminate cultivar ‘Green Giant’ with a historic 1890s Burpee dwarf called ‘Golden Dwarf Champion,’ and called the resulting cross ‘Sneezy.’ For our project, we always use the dwarf as the pollen accepter, or “mother,” because it’s easy to tell if the cross worked. Indeterminate growth is dominant, so if pollen is applied to a dwarf flower, and the seeds from that fruit are saved and grown, a resulting indeterminate plant confirms the success of the cross. We blew right through all of the Disney dwarfs; we now have over 90 families, so we’re getting quite creative with family names — ‘Sleazy,’ ‘Nosey,’ and ‘Messy’ are a few.


This is fruit from the dwarf tomato cultivar ‘Purple Heart.’ Photo by fruitionseeds.com.

The F1 hybrid shows a combination of the dominant traits of both parents and is often ordinary in appearance and flavor. Seeds saved from the hybrid represent the real start of the project — the drama, the mysteries, and the discoveries play out once the F2 seed is planted. The various traits of each of the parents, and some unexpected combinations, begin to show themselves. Promising candidates for new tomatoes are identified and named by the discoverer, but it takes a lot of growing and selecting over generations to arrive at a stable, new tomato. Our project aims for stable open-pollinated releases that will be reproducible from saved seeds. In essence, this project is a way to create a set of “tomorrow’s heirlooms” — tomatoes that, in 50 or 100 years, if they’re still being grown and shared, will be cherished and enjoyed.


Defining F1: In genetics terms, the plants used for the very first cross in creating a new cultivar are the “parent” generation; their offspring are called the “F1” generation, meaning “first filial” generation. Subsequent generations are named “F2,” “F3,” and so on. For tomatoes, a stable cultivar is usually achieved after about 10 generations of consistent selection for the desired traits. Photo by Adobe Stock.

Patrina and I serve as data and seed collectors, as well as disseminators and deciders. We each have large, complex collections of the project’s efforts. We now have over 500 volunteers involved in the project. Some gardeners have been with us since the beginning, while others dabble in it, try it out, and sometimes decide it isn’t for them, only to return at some point in the future. It’s a wonderful, talented, generous group of people.


Project volunteer Bill Yoder displays some of the variety in a harvest taken from dwarf tomato plants. Photo by Bill Yoder.

When we have a finished tomato, Seed Savers Exchange member Bill Minkey grows out a few thousand seeds, we choose a seed company to do the release, and we send them seeds and the description. We’re also strong supporters of the principle of open source seeds, so we pledge our cultivars to the Open Source Seed Initiative.

While we’ve accomplished a lot with the Dwarf Tomato Project, there’s still a lot left to do. If all goes well, my book about the project will be released soon. With Bill’s work this year, we’ll have reached well over 100 releases by the end of 2018. Many of us are now working on dwarf paste and cherry tomatoes, as well as a selection with variegated foliage that’ll be quite ornamental.


The collective efforts of the many volunteers who contributed to the Dwarf Tomato Project have led to the creation of an incredibly diverse collection of dwarf tomato cultivars of varying colors, flavors, textures, and sizes. Photo by Craig LeHoullier.

We’re beginning to wind things down, but there’s always room for more volunteers. One thing to keep in mind is that the pay is terrible — as in there is none. Patrina, I, and all of our volunteers do this for the love of creating something new that will find use in gardens everywhere. Time will be the ultimate judge on how we’ve done, which is just fine with us.


 A Growing Interest

From the start, a small set of seed companies exhibited great interest in offering as many of the cultivars as they could manage. Victory Seeds is the main source for as close to the entire collection of dwarf tomatoes as owner Mike Dunton can see to. Other significant players include:

Fruition Seeds

Restoration Seeds

Southern Exposure Seed Exchange

Sample Seed Shop

Heritage Seed Market

TomatoFest


Craig LeHoullier is a tomato enthusiast, an educator, a co-leader of the Dwarf Tomato Project, and the author of Epic Tomatoesand Growing Vegetables in Straw Bales. You can learn more about his projects at www.CraigLeHoullier.com. If you’re interested in becoming involved in the Dwarf Tomato Project, you can reach him at nctomatoman@gmail.com.

Mother Earth Gardener
Mother Earth Gardener
Expert advice on all aspects of growing.