SICK OF WINTER? What I find helps, besides the occasional warmish, sunny day, is thinking about tomatoes. And that’s what we’re going to do today with Craig LeHoullier, author of the hit 2014 book “Epic Tomatoes,” who has over the years grown some 3,000 varieties in his home garden and adds new ones to his list every year.
Craig, who gardens in North Carolina, is a retired chemist with a longtime passion for tomatoes. He’s the co-founder of the Dwarf Tomato Project, an advisor on tomatoes to Seed Savers Exchange, and the person who in 1990 named the popular heirloom ‘Cherokee Purple’ from seed that had been passed down and eventually made its way to him.
Craig and Joe Lamp’l, the longtime public-television host of “Growing A Greener World,” are also partnering on the upcoming Growing Epic Tomatoes virtual course, which is open for registration now.
Plus: Comment in the box near the bottom of the page to enter to win a copy of “Epic Tomatoes” (affiliate link).
Read along as you listen to the February 28, 2022 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify or Stitcher (and browse my archive of podcasts here).
(Photo above from Joe Lamp’l.)
grow your best tomato, with craig lehoullier
Margaret Roach: Hi, Craig. Tomatoes, tomatoes, tomatoes.
Craig LeHoullier: Tomatoes. And, you know, I woke up this morning and it was 25 degrees and there’s frost on the grass, so tomatoes are now still in the dream state, but they’re coming.
Margaret: Yeah. So before we get started, I thought I’m going to buy a copy of “Epic Tomatoes” [affiliate link], your great book that has like 80,000 copies in print. Way to go, Craig. And I was so glad to reconnect with you with the excuse of our recent “New York Times” garden column that we worked on together with Joe Lamp’l, our mutual friend, too, who’s your partner in this upcoming Growing Epic Tomatoes virtual course, right? And I think that starts soon, doesn’t it?
Craig: It starts very soon, and in fact, Joe will essentially hijack my life for the next few weeks [laughter] as we do some… Well, last year was the launch, and we actually created the course as we went along. What’s going to be great about it this year is that it’s essentially done now and its self-paced. So people will be able to just take their time, work their way through it, and working with Joe was just an absolute joy. So any chance I get to interact with either one of you makes my day.
Margaret: Oh, that’s sweet. And I think people, then, you have like weekly live chats, so to speak, like office hours and all kinds of things for people. As they’re learning, they can ask questions and…
Craig: Yeah, hence the hijack. And there’s nothing like… When I look at a book and when you said 2014, it feels like yesterday. So, I’m getting older faster, because it’s been eight years since that book came out. But that book was written at a point in time, 2012, ’13, ’14. And what the course allows us to do is to make that book alive and up-to-date, and we incorporate everything that I’ve learned in the seven or eight years since. So what an opportunity to be able to make a book come to life.
Margaret: Right. So I followed your tomato adventures for many years, and I continue to do so on your blog, and on Instagram you’re @nctomatoman, I think. One thing that we never talked about before, though, that you brought up when we were doing the Times interview, was the amazing diversity of heirloom tomato varieties. I would’ve been off by many times over if you’d asked me to guess how many there were. And, what did you tell me? There’s like 12,000 known varieties or something?
Craig: Well, so, how I look at it is there is 10,000 to 12,000 varieties that have different names and it would take a lot of unscrambling, using DNA fingerprinting and sleuthing work, to find out, does that 12,000 named varieties really correspond to say three or four or 5,000 actually genetically distinct varieties?
And what happens, let’s say somebody named Joe is growing an heirloom called ‘German Johnson,’ and Joe’s family forgets that it’s ‘German Johnson,’ and in 10 years after they get it, “What is that tomato? Oh, that’s ‘Joe’s Favorite.’” Bingo. ‘German Johnson’ for that family now is ‘Joe’s Favorite.’
And so you see this type of a personalization of tomato names that’s happened probably countless times since the mid-1800s when Americans, “Wow, we decided tomatoes weren’t poisonous after all.” So this love affair in our country has really not been going on for all that long when you think about it, the mid-1800s.
Margaret: Right. So the 12,000-ish number came from the Seed Savers Exchange, the annual yearbook or something?
Craig: Yeah, it’s their yearbook and it’s their database, and what they do is they track all of the varieties that have come in with different names through all the years. So since the SSE got started in 1975, that 12,000 number does incorporate everything that essentially has passed through their records-
Craig: … in the intervening 40-plus years.
Margaret: Wow. Well, it’s pretty impressive. And those are heirlooms. And then there’s modern varieties, too. So, oh, my goodness.
Craig: Well, now is the time, Margaret. I mean, 2022, who would’ve thought that we’re gardening and growing tomatoes at the best time in history for all of that diversity to stick into our gardens?
Margaret: Yeah. So you’ve grown like 3,000 of these guys, or some crazy number.
Craig: Yeah [laughter].
Margaret: When you look at the catalogs, like we’re all thumbing through the catalogs still, January and then February. When you look at the catalogs, you look at the pictures, you read the descriptions, what are you looking for?
Maybe even better, what do you see when you look at those things? I mean, does the shape, is that where you think, “Oh, the fluted ones, I love those.” You know what I mean? Or is it color? Does the color say something to you? Like what’s… You’ve tried a lot of them.
Craig: Yeah. And you know what’s great about that question? Number 1, no one’s ever asked me. And Number 2, I’ve got a very unique approach in that, having such a huge collection of seeds, I essentially look through seed catalogs more to figure out what’s new and different, what’s coming back again. I probably will never order another tomato seed from a catalog for the rest of my life. Seriously-
Margaret: [Laughter.] Wow.
Craig: … because I’ve got them all. I’ve got browns and purples. And what I find is happening is, the things that are ending up in catalogs these days, it’s the flashy colors, it’s the flashy names. It’s typical Marketing 101 that we’ve used in this country forever.
It’s not snake-oil selling. It is, “How do I get people’s attention? I’ve got a red-yellow tomato and it’s named X. Well, I’ve got another red-yellow tomato, but I need to name it Y because I want to get a piece of that action. Sell it.”
So I’m a little amused when I look at the catalogs, at the efforts that’s made to make things interesting. The cover variety, you know, Burpee and Parks and all these companies have always put on these beautiful cover tomatoes, too. So I’m glad I’m not a seed company [laughter], because the competition out there is brutal to get gardeners’ attention right now.
Margaret: Right. You said that you’ll never have to buy any more seed. And another thing I learned from you recently was that you have some seed that you’ve been saving for many years and it’s still viable. Right?
Craig: Well, tomato seed, I’ve found, it goes off a cliff at about 14 to 15 years. So what I do is I regrow it each time and ensure that it doesn’t cross-pollinate in my garden. So for example, ‘Cherokee Purple,’ which I’ve been growing every year since 1990. It’s now 2022, and I have files on my computer that are PowerPoint that essentially tell the genealogical story of that tomato in my hands. Which year I grew it from, what it traces back to.
And I do that because if I end up with something I don’t expect, if I get a red one or a brown one, I can go back then and note, “Well, this lot of seed must have some cross-pollinated seed in it.” And when I want to grow it next year, I will go to a different lot. So I have maybe 80 different separate vials of ‘Cherokee Purple’ representing-
Craig: ... all of the times I’ve grown it in the last 40 years. Yes, I’m insane, but it’s O.K. [laughter].
Margaret: Yeah. And, where do you store your seed? All those vials? Where are they stored?
Craig: Yeah. So some of them are behind me in my office. Some of them are in my basement, and I don’t do what the big Svalbard [Global Seed Vault] does, what the USDA germplasm [repository] does, which is they dry them down and they store them at temperatures where they’ll last 50 or 100 years.
This is an issue that I have with my seed, because I’m storing them at room temperature. I’m getting maybe 10 to 12 years out of them. So I have this onus on me to make sure that everything in my collection is sitting somewhere else that is safe—whether it be the Seed Savers Exchange, the USDA, a seed company, Svalbard—because I don’t want anything to go extinct when it’s sitting in my hands, so to speak. I want to make sure that they’re always alive for somebody to grow out somewhere. That makes what I’m doing a little bit that much more complex, I think.
Margaret: Yeah. So, like a little mini-lightning round of some varieties, or that you-
Margaret: Is there something that you’re growing this year you’ve never grown before? Is there one you can name? Or…
Craig: Well, this year is really cool, because two years ago I thought… I have this little experiment. Let’s say I love ‘Cherokee Purple’ and I love ‘Lillian’s Yellow.’ And there’s lots of heirlooms I love, but what happens if I take those two and make a hybrid out of them? Will I love the hybrid?
So I did that eight different times with 16 of my favorite tomatoes. Last year the best tomato in my garden was the hybrid that was ‘Cherokee Purple’ times ‘Lillian’s Yellow Heirloom.’ Joe grew it as well. When you create a hybrid, you only end up with maybe 40 or 50 seeds, so I was very careful of who got to grow those out, but I saved seeds from them.
And so this year, I want to save room in my garden to grow out some of the offspring from that hybrid, because there’ll be different color combinations and different flavors and it will be just fascinating. So that’s the Mr. Wizard part of my gardening that I have to dip into each year, because that keeps me interested.
I’m going to have mysteries in my garden. I’m going to have questions that I can answer. But, the other thing I did the last two years is, because Hendersonville is such a better tomato-growing climate than Raleigh was-
Margaret: Where you moved from. Right.
Craig: Yeah. We had one day at 90 degrees last year. We had humidity that was extremely tolerable, so I had essentially little to no blossom drop. My yields were off the roof. So I went back and got a lot of my favorites that were starting to struggle for me in Raleigh, and we’re talking ‘Nepal’ and ‘Polish’ and ‘Yellow Brandywine,’ and they blew my socks off again last year.
And what’s comforting about that is, you’ve got things you’ve loved and they no longer are performing for you because the climate in your garden has shifted, so where those varieties are no longer happy and you move to a place where they’re happy again. So I fell in love once more with maybe a dozen of my favorite tomatoes and, well, I know, it’s kind of like Valentine’s Day was a few days ago, but it’s the same type of feeling, right?
Craig: Well, what it convinces you is that if you love the flavor of a tomato and you do a good job of keeping it so that it doesn’t cross-pollinate, you should be able to keep loving that tomato each year you grow it—like I said, though, unless the climate shifts to a point where it no longer sets fruit, or then it becomes a disease magnet, things like that.
Margaret: Right. So, you and Joe, when you teach the course in your own gardens at home, you have sort of a timeline. You like an eight-week seedling, and you ask us to count back eight weeks from our frost date and get started.
Margaret: And we’ve talked before on the show, a number of years ago, about your dense sowing method, how you don’t just put one or two seeds in a cell. You densely sow a number of each one in more of a larger cell or whatever, or a community pot, so to speak. What’s that about?
Craig: Yeah. Actually, the same type cell. So I’ve got that 50-plug flat that I like, that’s about one-and-a-half by one-and-a-half inch squares. And so maybe an example would be, there’s a fellow named Phil Shackelford who had a family heirloom, and he sent me two seeds. So I planted one and it germinated. And that variety is now in the Victory Seed catalog, and Phil is now all excited that his family heirloom can be shared, and it’s the biggest tomato I’ve ever grown.
But what I want to do illustratively next to it was ‘Sun Gold,’ which people were buying a lot of ‘Sun Gold’ seedlings from me. So I would sow 50 to 75 seeds in that same type cell, and it really is an efficiency trick.
And certainly not everybody has to, or even should do this, but it is possible, and that’s because if you wanted to create 3,000 or 4,000 or 5,000 seedlings, you can do it with two plug flats in a very small footprint in your office or growing area, whereas if you were to do 2, 3, 4 seeds a cell to create the same number of plants, every surface in your house would be covered with growing. So it really was just something that I learned about.
You can be efficient, and some of the people that have gotten the biggest benefit out of the dense planting are not even the tomato growers. It is the beet growers.
When I discovered that you can dense plant beets, and because each beet seed is actually a cluster of actual seeds, you don’t have to thin the beets in your garden anymore. You can just thin the beets out one little plant to a plug flat and then plop those plugs into your garden every three inches, and you get these perfect round beets.
Now you do have to enjoy playing in the dirt, spending hours at the bench, separating out seedlings, using a gentle touch. But I find that extremely therapeutic. When my hands are with seedlings, or with potting mix, that’s when I’m actually at my happiest. So I don’t mind doing that. But it isn’t for everyone, but it’s out there as a tool to use for those who need it.
Margaret: Right. So you started doing it, and Joe does it because he does a plant sale and you used to do a plant sale back in Raleigh and so forth, and so you’d grow thousands.
Margaret: But even for those of us, like say you want to do sauce or canning of tomatoes, and you want 12 of a particular variety. And by the way, what’s a great heirloom for canning? I know ‘Roma’ is a classic.
Craig: Well, so, ‘Martino’s Roma’ is probably the best of the ‘Roma’ types, but to me, ‘Roma’ is still… It is a canning tomato, it’s a sauce tomato. It’s not my favorite fresh-eating tomato.
Craig: So what I’ve gone with is things like ‘Golden Oxheart,’ or ‘Anna Russian,’ or ‘Cancelmo’ [above].They’re the big, one-pound, heart-shape varieties, which, because they have this genetic trait to have very few seeds and very dense flesh, they work for canning and sauce making equally as well as the typical traditional ‘Roma’ types, but they have a much higher flavor intensity to them. So you end up with much better-flavored sauce using those types.
Margaret: O.K. So let’s say I wanted to do a row… Maybe with my cherry tomato, I might have one plant, because I’m a small household, but, if I wanted to do my sauce for the year or whatever, I might have six or I might have 12 plants. So, O.K., if I wanted to dense sow those eight weeks before frost for the transplant date, I could put those… Instead of taking up 12 cells, two six-packs, I could have them in one cell or in a 3-1/2 inch pot, a community pot.
Margaret: And I have a small light. And I’m just trying to illustrate for people that even if they’re not doing a giant plant sale of thousands of plants, that would only be taking up that little square-
Margaret: … for the first four weeks of its life, those 12 plants. My-
Craig: That’s exactly right.
Margaret: … estimate is. And I would be able to move my lettuce seedlings under my lights, because I used to have this small light rig, and maybe some of my early kale and some other early things, in and out, in and out, in and out, before those 12 babies were ready to be potted on to their own individual cells for the second four weeks of their life, right?
Craig: Yeah, exactly right. And I’ve used that community pot 3-1/2 inch for lettuce often, and where I’ll take maybe 15 or 20 types of lettuce and just do teeny pitches of each in that one 3-1/2 inch pot and then it germinates, maybe I’ll have 50 or 60 plants, but they’re all different colors. And then, once I start to decide what I’m going to transplant, I can choose what I think would be an attractively colored mix when I pluck those out, and either put them in individual containers.
What I like to do with lettuce is move them to six to nine plants for a 3-inch pot. They really don’t mind root disturbance at all. There are certain plants that are a little bit fussy, but others—tomatoes, peppers, eggplant, lettuce, greens—you can be kind of abusive on them as you’re moving them around and transplanting them, and they don’t… Sometimes I feel like they just get relieved when they find fresh potting mix and a nice drink of water and they get separated from their friends.
Margaret: Well, and you know, if you see in nature when a plant self-sows, it frequently densely self-sows. [Above, dense-sown tomato seedlings; Joe Lamp’l photo.]
Craig: Yes, yes!
Margaret: So it’s not that you are doing something to them that’s not almost natural.
Craig: Yeah. I think what we do sometimes with gardeners is more unnatural by trying to make everything so separate and tidy, and that-
Margaret: Right. Symmetrical, right?
Craig: Yeah. That is a fantastic analogy you just made because the best way I’ve seen ‘Mexico Midget’ varieties grow is to have a container where they grew in. They self-seed. All of a sudden you’ve got these little clusters of 15 or 20 tomato plants coming up where each little cherry tomato fell. They’re coming out of that dry tomato.
Margaret: Correct. Correct.
Craig: And you just separate them out, put them in your garden. Cherry tomatoes are equivalent to weeds. You can’t kill them [laughter]. You can only hope to contain them.
Margaret: Yeah. So one of your other tricks, tips I love and it’s, I guess, because it’s the same way I do it. I gave up on using those domes that come with the seed flats or getting domes to go with seed flats. And I use plastic wrap, and you use plastic wrap. So after we’ve sown, and our medium is moistened and we’ve sown, and we’ve sprinkled some more—I think you use your colander to filter some more medium over the babies and mist it again—you put plastic wrap on, right?
Craig: Yes. Just loose. And the only downside of using it is, anybody who’s ever used a Saran or a Cling or whatever, it is so clingy. So you really have to be careful as you flip it each day because it will… So there are very few times people hear me swear in the garden. One is when the hose kinks. The other is when the plastic wrap all kinks onto itself and I have to keep getting fresh pieces of it [laughter].
Margaret: And you flip it every day-
Craig: Yeah, I flip it every day.
Margaret: … in order to keep disease down? Or what?
Craig: Yeah. So I’ve got a heat mat and that’s moist medium, which means that in the room is a little bit cooler. So each morning when I look in at that, condensation has formed as the warm soil meets. And what I don’t want is that same moisture touching the top of those seedlings day after day after day, because damping-off is the biggest enemy of very young seedlings.
And by doing that daily flip, that means the plants get reunited with a nice dry side of that plastic wrap each day. And then the wet part, which is now on the top facing out, that dries during the day. So you can use that same piece, flip it, flip it, and I’ve never had a damping-off problem since I’ve gone with that.
Margaret: Right. Yeah, I normally, once the babies are up, I not only remove the heat mat, but I also usually get rid of the plastic or the… You know what I mean? I don’t leave it once they’re well up and growing.
Craig: Right. Oh, yeah. So, if I’ve got 50 cells of 50 different types of tomatoes, there will be some natural variation on the timing of those, and once just about the majority of them have poked their head out, you’re right, that plastic… But then you’ve got to really watch your watering because you’ve densely planted.
Those plants are going to draw up more water, and that’s the other enemy of a young seedling that’s so shallowly planted seed. Those seeds aren’t that deep yet. So you can dry that off pretty quick. You got to just watch your watering. But once you get the hang of that whole technique, it’s a game changer, and I don’t even think about it.
It goes by so easily and so fast that I get a little disappointed, because it is one of my favorite parts of the gardening season, is sowing seeds and watching them come up. More fun than trying to tie a 10-foot plant to a stake and having it break off in a thunderstorm and all that stuff [laughter].
Margaret: So speaking of 10-foot plants, how about the opposite of those? I want you to put in the pitch for us to look… I believe the Victory Seeds catalog has all you and your collaborators’ Dwarf Tomato Project varieties. [Above, sliced dwarf tomato fruit from Craig’s garden.]
And I think you call them, it’s “the heirloom experience without all the pruning and staking” and whatever. Tell us. So give us the pitch for those.
Craig: I will. I will. And the other thing I want to alleviate is the confusion because I get a lot of emails. “Are all dwarfs determinate or indeterminate?”
And I say, “Well, think of them as the advantages of a determinate, in terms of ability to grow in a short cage or a short stake, but the advantages of the indeterminate, as being gradually fruiting throughout the season until frost.”
So what they do is, I tell people, if your ‘Cherokee Purple’ is 8 feet tall by August, your corresponding dwarf type will be 4 feet tall. The dwarf always holds that one half height ratio with the indeterminate variety. That makes them very useful. So you can get 20, 25 pounds of fruit off a plant. The key is to keep them healthy and happy, give them adequate feeding. We now have 145 varieties out.
Craig: Our 14 new ones are some of my favorites. ‘Dwarf Eagle Smiley,’ which is a yellow dwarf-growing cherry that tastes just about like ‘Sun Gold.’ And we’ve got ‘Dwarf Chocolate Heartthrob,’ which is a chocolatey-colored tomato with green stripes on it.
I mean, we’ve gone nuts. I am the mad scientist. But I owe it to the talents of the thousand or so people that have helped us since 2006 to play in the garden with us, and to grow the seeds I send and send me back the seeds they save and help me analyze them and decide where we go next.
The book is still not written yet. It is still in my head, but the Dwarf Tomato Project, which I will call “Crowd Breeding,” will be out hopefully within the next year, because it is such a story. No one has ever really done this type of a large-scale collaborative breeding project using all amateurs and volunteers, and none of us getting paid a cent. We’ve done it for the altruistic joy of bringing something new to gardeners, and it’s been the most fun I’ve had in gardening ever, I think.
Margaret: And they would be great in containers for those of us who have limited space, right? They would be great for that.
Craig: Yep. The catalyst for the project where all of the questions I’d get during seedling sale, “I want to grow a ‘Cherokee Purple’ or a ‘Lillian’s Yellow.’ What have you got that grows great and looks like it, but I can do it in a 5-gallon pot?” And the answer in 2004 was, “Not a whole lot.” And now the answer in 2022 is, “A whole lot.” So we-
Craig: Yeah. 145 and counting. So, yes. I keep trying to retire, Margaret, but it’s not working.
Margaret: Yeah, I’m having the same issue over here, Craig. Well, Craig LeHoullier, Mr. Epic Tomato, I wish you good luck with the course. I’m always glad to talk to you and I feel better. Even though my house is surrounded by a sheet of ice still, I feel better thinking about tomatoes. So, thank you, thank you, as ever.
Craig: It is always a joy. I had such a great time. Thank you, Margaret.
more tomato advice from craig
enter to win the ‘epic tomatoes’ book
I’LL BUY a copy of “Epic Tomatoes,” Craig LeHoullier’s hit book, for one luck reader. All you have to do to enter is answer this question in the comments box farther down the page:
What is the one (two? three?) tomato(es) you cannot imagine a garden without each summer? Do tell.
No answer, or feeling shy? Just say something like “count me in,” and I will, but a reply is even better. I’ll pick a random winner after entries close at midnight Tuesday, March 8, 2022. Good luck to all.
(Disclosure: As an Amazon Associate I earn from qualifying purchases.)
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 11th year in March 2020. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the February 28, 2022 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify or Stitcher (and browse my archive of podcasts here).