See what we’re harvesting at the Regenstein Fruit & Vegetable Garden.
©2014 Chicago Botanic Garden and my.chicagobotanic.org
Grafted tomato plants are available at garden centers and through mail order nursery catalogs, but sell out quickly, as the idea has captured the interest of home gardeners, farmers, and professional greenhouse growers.
An ancient art and science long used on fruit trees, grafting is the placement of the tissues of one plant (called a scion) onto another plant (called a stock). The rootstock is thought to impart disease resistance and increased vigor to a less vigorous—perhaps heirloom—tomato grafted on the top, producing more tomatoes over a longer period of time.
Curious about the process and whether the price tag could be justified—grafted plants run from $9 to $18 a plant—I decided to graft some tomato plants myself and grow them out. My first foray was in winter 2013. The Chicago Botanic Garden’s propagator in the plant production department, Cathy Thomas, had just returned from a conference at Longwood Gardens, where one of the topics was grafting vegetables. She willingly supported my quest and enthusiastically discussed the details with me.
The process seemed fairly straightforward after we settled on which varieties to graft together. Deciding to graft the cultivar ‘Black Cherry’ onto ‘Better Boy’ rootstock, we worked with tiny, 3-inch-tall tomato starts, taking care that the top and bottom stems of each plant were exactly the same diameter at the place they were to be grafted. Our grafting tools included clear silicon tubing cut to 10 to 15 millimeter lengths, a new, unused razor blade, and our tomato seedlings.
Starting by sanitizing our hands, we used a new razor blade to slice the stem of the scion (top graft plant) off at a 45-degree angle. The plastic tubing, soon to be the grafting clip that would bandage the graft union, was prepared by splitting it in half. All the leaves were removed from the scion, leaving only the meristem. (The meristem is the region of stem directly above the roots of the seedling, where actively dividing cells rapidly form new tissue.) Two diagonal cuts were made, forming a nice wedge to fit into the rootstock. The rootstock was split and held open to accommodate the scion. A silicon clip was slipped around the cleft graft. Newly grafted plants were then set into a “healing chamber,” a place with indirect light and high humidity, for up to a week. In the healing chamber, the plants can heal without needing to reach for light, which can cause the tops to pop off. We placed our new grafts in a large plastic bag in the Regenstein Fruit & Vegetable Garden greenhouse. The healing began.
Two weeks later, we had a dismal one-third survival rate! Much to my relief, the lone survivor was a superlative tomato plant in almost every way. Oh, what a strong tomato we had! My excitement rose—what if heirloom tomatoes could be as delicious and more prolific and adaptable? When soils warmed, we planted our grafted tomato out in the Fruit & Vegetable Garden, positioned right next to a ‘Black Cherry’ plant growing on its own root, so the differences would be easy to discern. Our hope was that we could address some of the ins and outs of grafting for the public, and the feasibility of DIY (Do It Yourself) for gardeners. Do grafted heirloom tomatoes have more vigor, better quality, and bear more fruit than ungrafted “own-root” heirloom tomatoes? Which has a more abundant harvest over a longer period of time?
Last summer, our grafted tomato plant certainly provided the earliest harvest. Comparatively, it was earlier to fruit than the plant grown on its own root by two weeks, and was prolific throughout the season. That being said, in the organic system of the Fruit & Vegetable Garden, our soils are nutrient-rich and disease-free in large part due to crop rotation and soil-building practices. The question used in marketing “Is the key place for grafted tomatoes in a soil that has disease problems?” didn’t apply to us. Are grafted tomatoes the answer for those with less-than-ideal environmental growing conditions? For greenhouse growers unable to practice crop rotation as a hedge against a build-up of soil-borne disease, or home gardeners who contend with cool nights and a short growing season, I would say yes, I think so, but at a cost.
When planning on grafting, growers must buy double the amount of seed and need to double the number of plantings (to account for the graft failure rate) to maintain the same number of viable seedlings to plant. Cathy and I tried our grafting project again this spring and are looking forward to growing ‘Stripes of Yore’ and ‘Primary Colors’ on ‘Big Beef’ hybrid rootstock. I swapped seed for these unusual varieties with a tomato enthusiast who attended our annual Seed Swap this past February. Our rootstock has excellent resistance to common tomato diseases: AS (Alternaria Stem canker), F2 (Fusarium wilt), L (Gray Leaf Spot), N (Nematodes), TMV (Tobacco Mosaic Virus), V (Verticillium Wilt). So far, three of our eight plants are viable, healed, and strong.
We are looking forward to planting the grafted tomatoes the week of June 8 in the Fruit & Vegetable Garden, right alongside some of the other 52 varieties of heirloom and hybrid tomatoes. So whether you choose a regular or a grafted plant at the garden center this weekend, come on over! It’s time to talk tomatoes! @hilgenberg8
©2014 Chicago Botanic Garden and my.chicagobotanic.org
When Larry Aronson stepped in to substitute for a scheduled chef during a recent Garden Chef Series demonstration, the long-time Chicago Botanic Garden volunteer brought three important things with him:
Aronson knows tomatoes, and he knows that many of us are just starting to pick the first ripe tomatoes from the vine. (Cooler nights have delayed ripening.) What can a gardener do with just a few tomatoes from each plant, instead of a bushel full?
The flavorful sauce was a hit at the chef demonstration that day, and it was a hit with the volunteers and staff who got to sample it at a follow-up luncheon. At the latter, Aronson also served the “winter” version of his sauce—same recipe, but made with canned tomatoes instead of fresh. Both were tasty, in different ways: the “summer” version was light, bright, and refreshing; the “winter” sauce was thicker, richer, and heartier.
Aronson will have copies of his recipe on hand and will be talking tomatoes when he volunteers at Heirloom Tomato Weekend this Saturday and Sunday (11 a.m. to 4 p.m. each day). Stop by to talk tomatoes—and recipes!
We’re happy to share the recipe here, too—just in case you need it for tonight’s tomato sauce.
©2013 Chicago Botanic Garden and my.chicagobotanic.org
Our “founding gardeners”— author Andrea Wulf’s depiction of early U.S. presidents who passionately promoted farming as a means to independence — would be tickled to see the American Seed Saver bed in the Regenstein Fruit & Vegetable Garden. There, visitors will find varieties of heirloom fruits and vegetables grown by our third president, Thomas Jefferson, in his country estate at Monticello, just outside Charlottesville, Virginia. Many of these varieties are also grown in Michelle Obama’s organic vegetable garden on the White House grounds.
The American Seed Saver bed also honors everyday gardeners who help safeguard the genetic diversity of plants, according to Garden horticulturist Lisa Hilgenberg, who oversees the Fruit & Vegetable Garden. “Because of the work of home gardeners and seed-saving organizations, an increasing number of heirloom varieties are now available to the public,” she said.
Heirloom vegetable varieties are open-pollinated plants that reproduce themselves, staying “true to their parents,” according to Hilgenberg. They’ve been handed down through generations, a practice that helps maintain the food crop gene pool for future generations.
The Abraham Lincoln tomato (Solanum lycopersicum ‘Abraham Lincoln’) was planted in our American Seed Saver bed as a tribute to our 16th president, who established the United States Department of Agriculture more than 150 years ago. The big, sweet, and juicy tomato is a good slicer and also makes great ketchup. “What could be more American than that?” Hilgenberg said. “Other cultures dry their tomatoes or make paste. We’re going to put them on our burgers.”
Visitors to the American Seed Saver bed can also see the rattlesnake bean (Phaseolus vulgaris), said to originate from the Cherokee people. The variety is also known as the preacher bean because its abundant yield of purple-streaked green pods gives cause for thanks and praise. The nearby Painted Lady bean (Phaseolus vulgaris ‘Painted Lady’), native to Mexico, was popular in England by the 1850s and a favorite in America by the early 1880s.
The sweet and spicy Alma Paprika pepper (Capsicum annuum ‘Alma Paprika’), of Hungarian origin, can be dried and ground into paprika and is cited in one of the earliest American cookbooks, according to Hilgenberg. In the American Seed Saver bed, the plant also serves as a symbol of America as a melting pot of cultures and traditions. “We’re such a nation of immigrants and now we have gardens with plants from all over the world,” Hilgenberg said. “We’ve made them our own.”
©2013 Chicago Botanic Garden and my.chicagobotanic.org
As farmers’ markets wind down, many of us want to preserve the bounty of this year for the next. Why not save save seeds from your last tomatoes so you can grow them yourself next year?
1) Make sure to save the seeds from an open-pollinated or heirloom tomato. These seeds will reliably reproduce the “parent plant.”
2) Choose a ripe, disease-free tomato; one past being edible is best.
3) Cut the tomato ‘around the equator’ and squeeze out the seeds and ‘goo’ in to a strainer over the kitchen sink. Run cold water over and use your fingers to try and separate the ‘goo’ from the seed.
4) Knock the strainer on a paper plate lined with a coffee filter, dislodging the seeds from the strainer.
5) Label the filter with the tomato variety and let dry which could take up to three weeks. The top of the refrigerator is a great place for this.
6) When dry, scrape the seed in to an envelope labeled with the variety and the date for storage. If the seeds stick to the coffee filter, simply fold the whole thing up and store in the envelope. The filter itself can be planted; it will disintegrate.
7) Store your heirloom tomato seeds in a cool dry place indoors. I like to put them in my top desk drawer.
8) Seeds have varied life expectancies. Tomato seed is viable for 4-10 years.
9) Check back in late winter for a blog post about a simple germination test checking to see if your seed is viable.
Mark your calendars for the Second Annual Seed Swap on February 23, 2013. For more information on seed saving visit our web site.