Secrets to Growing the Perfect Tomato

Ken Cook is out to perfect New Hampshire's official state fruit.

Ken Cook of Rusty’s Heirloom Tomatoes in Dunbarton Photo by Susan Laughlin

It’s all about taste for tomato guru Ken Cook of Dunbarton: “If they taste great ‘naked’ with just a bit of salt and pepper, then they will taste great in a salad or sauce.” he has dedicated his retirement years to developing a more perfect union of tomato crosses in search of an easy-to-grow, yet superb-tasting, specimen. from fermenting seeds to adding gourmet-quality soil amendments, he shares his top tomato secrets with us.

It’s hard not to like a guy who has thrown his life’s pursuit into creating the perfect tomato for your salad. That, and he named his most perfect tomato, and business, after his orange farm cat. Rusty’s Heirloom Tomatoes is based in Dunbarton and Ken Cook is spending his retirement years pollinating blossoms, saving seeds and planting 600 tomato plants every year in a pursuit to develop the most tasty — meaning sweetest — tomato around. He, or maybe Rusty, is working on the perfect Oxheart tomato, sweet and laced with stripes. It would be a first of its kind  — kind of a holy grail for tomato aficionados.

With the exacting mind of an engineer, Cook keeps track of his tomato trials, seed collection, breeding selections, planting regimes and most importantly, tasting notes.

Like any gardener, Cook spends the winter months perusing garden catalogs and building his arsenal of supplies for the coming season. Come the end of March and early April the first seeds, 300 or so, are planted in trays and lit with fluorescent lights in the basement. Before sowing, he soaks the seed for three hours in a green tea solution that contains tannic acid and a few nutrients that speed up germination. The germinating plants are nurtured on heated pads and finally brought into the sunroom upstairs after they develop their first true leaves.

Cook then gradually deploys the plants outdoors on an acre of specially prepared raised beds scattered around the farm. Most are grown to sell to restaurants and at the onsite farm store in late July through September. In May, Cook sells seedling plants to area gardeners who are given thorough instructions on their care and feeding. He does not sell seeds, but rather trades the most desired to other tomato gurus across the country.

Unlike most other gardeners, Cook’s seeds and plants are not Big Boy hybrids, but heirloom varieties he has saved from last year, years past or special trial seeds he is growing out for other tomato breeders, especially Tom Wagner of Everett, Wash., who developed the acclaimed and tasty Green Zebra tomato in the 1970s.

Why heirloom varieties? Cook claims that the hybrid tomatoes grown by large producers were bred for shipping and not taste. They have thicker skins, and the seeds cannot be grown out predictably “true to type.” Heirlooms are prized for their natural disease resistance, super taste and variety of sizes and shapes. They fruit in a variety of colors including white, pink, yellow, brown-green and purple ­­— a virtual paintbox for the determined breeder.

There are many more heirloom varieties than hybrids available at the grocery store, and even more being bred. They are not considered hybrids because the seeds can be saved and replanted and will come up true to type. But this all takes years, especially with New Hampshire’s short growing season, where only one cycle can be completed. According to Cook, it can take seven to eight full cycles to establish a stable segregation line — a desired variation of the two parents that can be duplicated.

Cook has developed 25 successful crosses through the years, but they are all not officially stable yet. One of his favorites is Sun Spot, which is a cross of Sun Gold, a cherry tomato with the desired characteristic of a high brix count (10), and Stupice, which is a tasty early globe tomato. The result is a very sweet and earlier cherry tomato.

Rusty’s tomatoes that are under development and may or may not be available as fruit or plants

From top to bottom and left to right:

  • Angora Super Sweet: AKA Velvet Red is a mideason cherry tomato great for cooking and paste
  • Sweet Beverly: Midseason, drought tolerant, brilliant yellow/gold cherry type sweet with a slight citrusy finish
  • Maguy: Small beefsteak good for slicing, from Germany
  • Osu Blue: Small tomato exhibiting blue characteristics in flesh and stems. Other tomatoes carrying a true purple gene include Purple Calabash, Indigo Rose, Blueberry, Bing Cherry, Primary Colors and Blue Green (The Cooks personally find it of average taste and therefore do not sell the OSU Blue, but rather grew it a few times for the novelty of the color)
  • Shaker Village: Midseason pink variety good for paste, stuffing or sauce
  • Orange Minsk: Originally obtained from a farmer’s market in Minsk, Belarus. This is a very impressive tomato! It is one of the earliest large orange beefsteaks and it also has great taste. The large fruit are a beautiful orange color and have ribs on the stem end of the fruit.
  • Solar Flare: Large red beefsteak with gold stripes with very, very meaty flesh and  luscious sweet red tomato flavor
  • F5 Bluegreen: The fifth segregation line of a new blue-green variety being developed for superior antioxidant qualities

Tomatoes are pollinated by shaking pollen from the anther to the sticky stigma, and this is accomplished in nature by the wind or, on occasion, by bees. It can be done by hand with care. Once the crossed tomato bears fruit, its seeds are saved and planted the following season. It is not until next year when that plant bears fruit that the results are visible. There could be about 256 variations possible, but Cook explains there are usually only seven or so variations on the 30 crosses. If one or more of them display the desired traits, such as stripes, no cracking, the desired shape and most important, a great taste, the seeds are saved for another round next year. At this point those seeds would be considered an F2. For a seed to be stable and stay true to type it needs to go to the F7 level. That would be the seventh grow out. Of course, in warmer climes it is possible to get three cycles in one year.

Patience, patience and more patience. Cook seems to have plenty of that as he carefully saves seeds and even more carefully charts and categorizes the results each year.

Ken Cook goes over his planting diagram to see how each variety is growing.
Photo by Susan Laughlin

Another project Cook has thrown himself into is the Cross-Hemisphere Dwarf Tomato Project. The idea is to develop a compact, but prolific tomato plant that thrives in a small container, one ideal for a patio garden. As more people learn to enjoy local foods, they could more easily just grow their own, even in limited space. Twelve new varieties were released in 2011, including Dwarf Beryl Beauty, Dwarf Emerald Giant, Dwarf Mr. Snow, Dwarf Wild Fred, Iditarod Red, Perth Pride, Rosella Purple, Sleeping Lady, Summertime Gold/Green, Chocolate Champion and Tasmanian Chocolate.

Dwarf tomatoes are distinctive with thick stems that don’t need stakes and have stout compact growth and dark bluish-green rugose (puckered) foliage. The plants themselves are determinate, meaning their height is limited and they don’t continue to sprawl as indeterminate types would. Growers across the world are sharing and advising in a type of crowd-sourcing to speed up the development.

One characteristic that Cook is selecting is the color blue. The blue/purple gene is rich in lycopene and has a higher antioxidant content. The trick is to make it nutritious and delicious and that takes determination, trials and time.

Cook is getting his tomatoes out to chefs and restaurants for terrific salads this September. On his list are Chef Cory Fletcher at the Granite Restaurant in Concord, Chef Ed Aloise at Republic in Manchester, the Hanover Street Chop House in Manchester, The Crust & Crumb Baking Company in Concord and the Country Spirit in Henniker.

When Chef Aloise first tasted the fruits of Cook’s labor he said, “Now, that’s a tomato.”

Maybe that says it all.

Rusty’s Quiz

Rusty’s Heirloom Tomatoes is named after Rusty the orange farm cat, shown here hard at work “watching” some tomatoes grow. Test your tomato knowledge with Rusty’s quick quiz. Answers can be found at the end of the story.

Where did tomatoes originate?
A. South America
B. Hawaii
C. Italy

How many named tomato varieties are there?
A. 13,390
B. 1,390
C. 130,900

What color is tomato skin?
A. Clear
B. Red
C. Yellow

Saving Seeds

Cook has a special method for saving seeds. After scooping the seeds with pulp into a cup, he adds water and puts the cup in a warm spot, specifically the top of his refrigerator. After three to five days of fermentation (stirred each day), the mold layer is scooped off and the seeds are rinsed and stirred two to three times. Finally he rinses the seeds well under warm running water and spreads them on a coffee filter to dry.

The fermentation has eaten the gel naturally found on the seed and they will now sprout more efficiently. He then marks the variety and the generation on a small brown envelope and stores them in his seed closet for the coming year. He has successfully grown seeds that were 20 years old.

Soil Basics

The path to the perfect tasting tomato lies in the soil. Top soil today, especially that of commercial large-scale producers, is stripped of its full complement of nutrients. Cook goes to great lengths to fortify his soil every year with a broad spectrum of nutrients, minerals and trace elements. Besides worm castings, compost, alfalfa meal and bone meal natural fertilizers, he adds azomite (pictured on the right) mined in Utah from deposits left by an ancient volcano eruption. The dust contains more than 70 trace minerals important for any plant to reach its full potential.

The “Law of the Minimum,” developed by Justus von Leibig, states that plant growth is determined by the scarcest “limiting” nutrient; if even one of the many required nutrients is deficient the plant will not grow and produce at its optimum. Cook sees that, when plants have all the resources, they develop well and produce tasty fruit.

Tips on Tomato Culture

  • Rotate your vegetable crops. Tomatoes, peppers, potatoes and eggplant are all in the Nightshade family so avoid contiguous plantings of same family groups.
  • Mulch heavily to prevent soil from splashing up onto the bottom leaves after heavy rains or watering.
  • Ideally, tomato plant spacing should be two feet for determinate plants and three feet for indeterminate plants to allow plenty of light and air circulation. Clip off branches in the lower 12 inches.
  • Do not water overhead with sprinklers, use water at ground level to keep leaves as dry as possible.
  • Add a lot of compost and organic matter to suppress diseases.
  • Never work in the garden when it’s wet or rainy to avoid spreading disease.
  • Check plants daily for disease; cut off affected leaves, wash hands and use tools cleaned in a 10-percent bleach solution.



Quiz answers: All answers are A., except the last question, which is A. and C.

Categories: Features