ripening tomatoes—and saving seed, with craig lehoullier

AROUND THIS TIME each summer, I look forward to the onslaught of fresh tomatoes while at the same time hoping against hope that what I call tomato troubles don’t reveal themselves and get the upper hand. I’ve been hearing from lots of readers and listeners in recent weeks that the new normal of weather chaos nationwide and worldwide isn’t helping them get to the tomato finish line successfully and that they’re worried.

With all that in mind, I made my annual frantic call with some urgent tomato questions to today’s guest, Craig LeHoullier in North Carolina, the NC Tomato Man as he’s known on social media, author of the classic book, “Epic Tomatoes” (affiliate link).

Craig knows more about these cherished fruits than almost anyone I’ve ever met. He even shares that in live sessions each week on his Instagram account where you can ask your questions and get solid answers.

I asked Craig how he’s doing and what we should all be doing to bolster a bountiful harvest and also about which fruits to save next year’s seed from anyhow and other tomato questions.

Read along as you listen to the July 31, 2023 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).

Plus: Comment in the box near the bottom of the page for a chance to win a copy of “Epic Tomatoes.”

ripe tomatoes (and saving seed), with craig lehoullier

Margaret Roach: Hey, Craig. How are you?

Craig LeHoullier: Hi, how are you? It’s just wonderful to be here chatting with you. And it’s so timely, because today I went out and actually harvested the first actual non-blossom end rot induced ripened perfect tomatoes for my garden. So we’re late. We’re about two, three weeks later than usual here.

Margaret: Whoa! O.K. So I was going to ask you, how’s the harvest in Hendersonville in North Carolina? So now you said something about blossom end rot, and I saw that on Instagram. You had some sort of deformed-looking tomatoes going on there. [Laughter.]

Craig: I don’t know if I should be alarmed or charmed, but people seem to love it when I show them my problems. Having been a gardener for 40 years, I think it’s really important to make it clear that there is no perfect garden, there is no perfect season. We just have things we deal with. But by and large, if we do the right things, things come out pretty well. So we’re just starting. We had a relatively cool, wet spring, which meant the seedlings didn’t really progress visually. I’m sure the roots did really well. But they didn’t look like they were doing a whole lot. So everything got in the ground a week and a half later.

Here’s an interesting marker, is Saturday was Hendersonville’s Tomato Day. I actually had to back out because you can’t have Tomato Day when you have not a single tomato to taste [laughter]. So well, people try to… they try to get the right date for these big events.

Margaret: Sure.

Craig: Any time people are trying to time a gardening event, gardening as a whole can fool us. And it just did this year by making it a very late season relatively.

Margaret: Well, and it’s not just tomatoes, Craig. I mean, yesterday I heard from a friend near me, where usually the fall Japanese anemones bloom in August, who has already had them for a week in her garden. And I think my oakleaf hydrangeas came about two, three weeks early this year, and on and on and on. So I mean, a lot of differences in this aberrant new normal thing that’s going on.

Craig: Yeah. Do you think our attention is trying to be gotten a little bit? [Laughter.] My wife and I love to grow all kinds of flowers, and I agree. Watching how our various perennials and flowering shrubs did or even didn’t bloom this year has been very, very instructional on how they feel about all of this.

Margaret: Right. Well, where I am up in the Hudson Valley of New York, fruit growing is one of the important farming things that goes on here. All the cherries and peaches and even a lot of the apples were lost in a very late, very hard freeze and so forth. And I mean, I think tomatoes are coming in, but we’ve had loads of crazy rain and humidity. And I know farmers and gardeners around me, and maybe around you, too, are worried about fungal issues, things like you and I talked about last year around this time when I made my frantic call [laughter].

And I’ll link to that fuller conversation. But just the basic rundown by this time in your summer when you’re trying to stay ahead of the problems, what’s the basic protocol, the cheat sheet version of it, what you are doing.

Craig: Sure. Well, I think first of all, I learn something… Even after all of those decades of gardening, I learn something every year because I observe and then I put my thinking cap on and I try to make sense of what I see. So I got a lot of questions this year from people saying, “My tomatoes are blossoming really, really well, but some of those flowers are falling off.”

So I developed this theory that the plant kind of knows what it’s doing. If you have a plant with 100 flowers on it, they’re not all going to form, because you can’t have 100 pounds of one-pound tomatoes on a plant. So the plant knows that it’s doing too much. So-

Margaret: It’s self-thinning, right? Isn’t that self-thinning?

Craig: It is self-thinning. Yeah. It is aborting flowers because it’s decided, “Given what I’m being watered and giving what I’m being fed, this is more than I can handle.” So I eased a lot of people’s minds on that. So everybody’s keeping an eye on that.

However, you brought up an interesting point, because even though a season may start late in terms of harvest, humidity doesn’t wait, rain doesn’t wait. Especially wet foliage that sits overnight. So you do get the inevitable fungal issues. People send me a picture of a leaf that has a little blemish on it and they’re really worried about it, and I’m like, “Oh, get in line.”

Margaret: You ain’t seen nothing yet [laughter].

Craig: “That is one leaf.” So anybody the world over that grows tomatoes in warm, humid areas will have Septoria leaf spot, they’ll have early blight. They may have both on the same leaf.

The control of that, which brings me to my other point… We get warm, we get tired. So the best gardens you can have are when you find the wherewithal within yourself to go out on that hot, steamy day with your scissors and your bucket and get the ugly foliage off the plant.

Or go out at noon when it’s 95 degrees and realize your plant’s wilting, I have to get water on it because it’s going to stress. If that plant stresses, I’m going to get blossom end rot.

So these are the times that try tomato growers stamina and focus. Being 67 now, I feel differently than I did when I first gardened, when I was 27. I sometimes don’t have that reserve, that energy, and the air-conditioned house and the couch calling, “Take a nap, Craig. It’s a warm afternoon. It’s nice in here.” So what I do is I pay the price. And the fungus on the foliage has one additional day or two additional days to spread onto additional plants.

So there is a cause and effect with this. The more engaged you can keep yourself, the more stamina you can find, the more resolve you can get in there daily and spot where those problems are and… Maybe it’s the little hornworm that’s a half an inch long today and it’s 3 inches long and has eaten one-quarter of your plant tomorrow. So there’s a lot to be said for energetically and… gardening like you really mean it, and not just-

Margaret: So it’s the long game you’re saying. That we have to play the long game and we have to… Hygiene is key, especially as we get into this humid… with these older plants that are already under the load of trying to reproduce to make the fruit, ripen the fruit. We need to keep the nasty infected stuff and the 3-inch-long hornworms off them [laughter]. We have to give them a break, right?

Craig: And it’s when the plants have grown that you start realizing that you’ve created pools of shade. So I’ve got plants that are dwarfs and grow bags that are being shaded by indeterminates. So I know that those are the plants that are going to give me the biggest trouble with fungal diseases.

Sun is a marvelous disinfectant. If you could get air blown through your plant, if you could get sun shining on your leaves all the time, you would really minimize those fungal infections. But the back of the plant, the interior of the plant, the low foliage does end up getting shaded as the plants grow.

So I’m already thinking design differences for my plants next year, more adequate spacing, more adequate choreography of which types of plants are going to be where, so I’m not shading other parts of my garden.

I guess what I’m saying is, it’s never too late to start planning for next year, which is the important of a log, or in my case a blog or Instagram Live, which is… That’s a garden log for me. I can go back over an entire season, and if I so choose to bore myself with myself, I can watch what are the things that I talked about on particular dates that I told myself I need to be careful to watch out for this next year.

Gardening is an exercise in continuous improvement. And that continuous improvement actually lasts a lifetime, or all of the years that you’re going to grow a garden. And that makes it really fun, I think.

Margaret: Yeah. So what we’re really seeking are ripe tomatoes. So at what stage does Craig actually pick from the vines? What do you consider the moment? Because some people wait until it’s fully ripe and, “Oh, I can eat it out of hand standing in the row.” And some people pick at a less-developed and… And then there’s at the end of the season when… especially up north, when frost is threatening and we might have a lot still green. So what’s your strategy for when to pick?

Craig: This has evolved over the years. A lot of the evolution has been my interactions with Joe Lamp’l, where we’ve put our heads together and thought-

Margaret: Oh, Joe.

Craig: … about that as well. Yeah, Joe. He’s-

Margaret: Yeah. And we should just say, you, Joe Lamp’l, joegardener dot com, and… you’ve done a whole tomato course that you guys do together the last few years and it’s very popular. Yeah.

Craig: What was great about that is we learned from each other, and we learned collectively as a twosome, because we would talk over things and change our methods. But I’ve become a breaker-stage picker, meaning in… If anybody watches the little one-minute reel that I put on Instagram today, I actually show my very first picking. They’re laying on the counter, and they’re only about one-third to one-half ripe. Why did it do that? Because we get these heavy thunderstorms, and I’m watering regularly, and there’s no better way to crack a tomato than to let it get fully ripe and then have water applied to it, either by nature or by us. The tomato just can’t handle it. It swells and the skin-

Margaret: The skin… Right.

Craig: … cracks. The skin just cracks. The other thing is, I don’t know if anything is more tempting to critters in your garden than the smell of an absolutely fully vine-ripe tomato. So you can also minimize pest and critter damages if you get them off the plant a little bit earlier.

Another fringe benefit is I have found that the shelf life of tomato that’s ripened more slowly indoors lasts a little bit more. Very few things are more perishable than an absolutely dead-ripe-picked tomato. You bring in the house and within a day or two, it’s already melting on the shelf into a puddle of nasty-smelling stuff. The fruit flies know exactly. Yeah.

And Joe and I have both done this test. Once you let it ripen indoors on your kitchen counter over a few days, the taste becomes totally indistinguishable between that shelf-ripened tomato picked a little bit early and the fully vine-ripe. Sometimes the taste is a little better because a fully vine-ripe tomato can actually be a little bit overripe. And when a tomato gets overripe, the flavor flattens out. You lose some of the sparky sense of tingly acidity to it, and you just can get a flat, funky flavor out of it.

Yeah. And these are things I’ve just learned the last three, four, or five years as a new best practice. And when they start coming, I pick six or eight tomatoes, and I’ve probably got hundreds out there. So the other thing to have in mind is your strategy for dealing with the whole ocean of tomatoes that will flow in way too close together to each other.

Margaret: Right. Of course.

Craig: So get your canning jars, get your lids, get your bands, get your freezer bags, get your recipes, and get your friends so you can give them away [laughter], hold a tasting, all of those things.

Margaret: Well, at the beginning of that answer, you said something. You said you pick at the breaker stage. And I think it’s fun for people. And with the transcript of the show, I’ll show the illustration from… I believe it’s the USDA. It’s like a vintage illustration that I have. They name and they show you color pictures of the different phases of ripening. And you have to get to a certain point or it can’t ripen off the vine. If you pick a solid green tomato, it’s not going to ripen on the kitchen counter. It’s got to be at least at that… I believe at the breaker or something stage. So just explain that real quick.

Craig: Yeah. Well, so the first thing is, if you pick a fully sized green tomato and you bring it in and put it near an apple or banana, the ethylene given off will actually ripen it to the point where it won’t be the best tomato of that type you ever ate. But the seeds are actually viable for seed saving inside.

Margaret: O.K.

Craig: So at the end of the season, if you’re finding yourself loaded with green fruit, you haven’t done your seed saving yet, don’t worry. Bring them in, put them in a big paper bag, make sure you label them, put a ripe apple or banana, and within a few weeks, you’ll have ripe tomatoes with viable seed that you can reuse.

Margaret: Fully developed green fruit. You said that, right?

Craig: Now, the tricky part of the breaker stage is we now have tomatoes in an array of colors. So this is where learning comes in. What does a pink tomato look like at breaker stage? What is a purple, a brown, a red? The most difficult one of all to pick at breaker stage is the ones that are green when ripe [laughter] because they barely… Seriously, they barely change color even when fully ripe. So that’s when you need to do the Charmin squeeze test on the base of the tomato, and if it starts giving just a little bit… You don’t want to dent it and bruise the flesh.

But you can practice. You can go up to the plant and look at some really hard green tomatoes and see what they’re like when you gently squeeze them, and then go and gently squeeze a ripe tomato and you can educate your fingers to know what to squeeze for. And that will help.

When the USDA did that, there probably just were red tomatoes at the time. So they need to redo their antique photo.

Margaret: That illustration.

Craig: Right. Yeah.

Margaret: Yeah. But the idea being that… generally speaking, what you said at the very beginning, don’t wait until it’s fully ripe on the vine. And you can be sure if it’s coloring up a little bit, you can bring it in and do the kitchen counter thing.

Craig: Absolutely. And here’s the other interesting thing. Tomatoes tend to ripen from the inside out. So even if a tomato looks fully green on the outside, if it’s getting to the point where it’s going to start to show color on the outside, if you cut it in half, you’ll see a core of pretty well-colored fruit. And that’s how grocery stores get away from calling tomatoes vine-ripened. They’re actually picked when there’s just a teeny bit of color in the center and they’re gassed with ethylene. And that’s to give them shelf life. But unfortunately, that does not give them edible texture and flavor. So-

Margaret: No. No.

Craig: Only home gardeners really and people who buy at farmer’s markets have learned to appreciate the absolute joy of a homegrown tomato versus a grocery-store tomato.

Margaret: Well, you mentioned seed saving and that we could save seed from these fully developed green tomatoes that then we ripen in the bag with the ethylene off-gassing other fruit and so on and so forth. But I was really surprised, and I had to… of course, as soon as I thought it through, I was like, “Oh, right. Of course.” The other day on social media, on your Instagram account at NC Tomato Man, you showed some really… I don’t know, they were like… They looked like multiple tomatoes glued together. They were like these incredibly misshapen tomatoes.

Then also some with what you were talking about earlier, blossom end rot, or BER [affecting the tomatoes above]. And you were saying you could save the seeds from those. And I was like, “Well, no, we want to save it from the… ” And then I thought, “No, no, Margaret. Of course that’s O.K. because those are like… they’re abiotic issues, they’re mechanical failures. They’re caused by something… They’re not pathogens, they’re not diseases.” Right?

Craig: I know.

Margaret: That’s right, right?

Craig: Now, wasn’t that a show of self-confidence on my part, that my first tomatoes I would show would be as ugly as sin, but I’m thinking-

Margaret: I’ve never seen anything quite like one of those [laughter].

Craig: I know. But here’s the point. So cracks, variable sizes, blossom end rot really do fall under the umbrella of physiological issues, meaning they’re caused by growing conditions, whether it’s temperature at the time. But all of the seeds of a particular tomato plant… So let’s say you’ve got, I don’t know, a ‘Cherokee Purple,’ 25 tomatoes on that one plant. Some are catfaced, some are ugly. The genetic material in every seed in every fruit on that plant is identical.

This was the great brainstorm that Alexander Livingston came up in 1870 where he was watching seed companies trying to improve tomatoes by saving seed from only the perfect fruit and then the next year getting the same mix of catfaced and ugly. So what he did is learned you have to plant a thousand plants of a particular variety and look for the single plant where all of the tomatoes on that plant are showing a distinct improvement, which indicates genetic difference.

And all of his new tomatoes were based on what he calls “single plant selection.” He was looking for the one or two superior plants in a field of thousands to base his future tomato developments on. That revolutionized all of tomato growing. But it didn’t stick, because if you look at all the seed catalogs, you would still see, “You have to pay extra for the seed because we saved it from the first perfect melon of the plant.” I’m like, “Big deal. You don’t have to charge extra for that.” But that was their form of advertising and pulling one over on the public so they could charge more for certain types of seeds.

We know better now that it’s… Well, the seed business is filled with hyperbole and exaggeration. Now we use Photoshop and filters to make everything look so much more perfect than we can grow ourselves. That’s really why I like to put my ugly, misshapen and funny-looking tomatoes on, because I always want to be a real gardener to people.

Margaret: One of the ones that you showed, and we can show the picture with the transcript of the show, again, it looked like it’s almost like two or three tomatoes stuck together. So what happens that makes that kind of multi-lobed, crazy looking… Is that multiple flowers? What goes on there?

Craig: So what you have there is a lot of the larger-fruited heirloom beefsteaks. The initial flower clusters, I like to call them marigold flowers. They’re really large and they’ve got so many petals inside. And it’s just a genetic characteristic of the large beefsteaks to have… Every so often they’ll throw a flower with that complexity. It’s kind of a fused blossom. It’s several flowers fused into one. So if by chance you get a tomato that forms on a flower like that, often they abort because it’s very difficult for pollination to occur in those types of flowers.

But if they do form, you get the multilobed, ugly fruit from it. A lot of times, temperature when fruit’s setting can also affect the success of even pollination. You can get some funny-looking ones.

What really frustrates people is when they pick a tomato that is multi-lobed and one of the lobes is dead ripe and the other lobe is totally green. What I do in that case is I try to sever the tomato right between the two halves and put the cut part of the green one, cut side down, in a plate to try to minimize the amount of oxygen getting in, hoping that it will catch up and ripen a little bit later than I can eat it.

But usually, I’ll just cut away the fully ripe part, enjoy it, and just… The other half that’s green, I may toss it or I may wait until it ripens a little bit and just use it for seed saving. But we see a lot of that early in the season. We see a lot of blossom end rot earlier in the season, because the plants are being called on to do so much. Here comes perfect weather, here comes all this nutrition and the watering, and “Ooh, I’ve got leaves and stems and flowers, and I’m pollinating.”

And the plant just gets a little overwhelmed. It interrupts the calcium flow into the fruit. That deficit is what causes the blossom end rot. So just a little bit of patience getting through those first one or two ugly fruit in a plant, and usually blossom end rot goes away all by itself, without having to cram a lot of calcium into the soil.

Margaret: So you were talking about seed saving and you… I think also on Instagram you might’ve mentioned recently something that I hadn’t thought about, which is that I think you save seed from early crops, having something to do with the bee population or something. Tell us about that.

Craig: So usually, early in the season when you still have relatively cool nights, the bees either haven’t shown up in any kind of numbers yet, or they’re off on basil and spring flowers [laughter]. So they’re leaving your tomatoes alone, which is really, really good. This is something I think people need to understand because they’ll say, “I’m really depressed about the bee population in my yard. I’m afraid I won’t get any tomatoes.”

Tomatoes are perfect-flowered, meaning they pollinate upon opening. They don’t really need the bees to help in any way. The bees, in fact, will cause problems later in the season by dragging pollen from a neighboring variety onto the flower. And if you saved the seed from that fruit, you’ll get interesting things. So I like to use the first one or two clusters, low down on the plant, prior to the bees showing up in numbers. And I tend to get about 95, 96 up to 98 percent purity of those first saved seeds.

And as a seed saver, that really is convenient, because then you’re not having to go out and bag blossom clusters with wood tulle or like a real thin fabric bag before they open and then let them pollinate. That’s a good way to do it. But I get a little bit lazier my old age, and I want to let nature and cleverness dictate how I do my seed saving.

Margaret: Do you squeeze the seed out of the tomatoes and ferment it in a little water? Or what’s your practice?

Craig: Yeah. So if a tomato is very ripe and juicy, usually just squeezing the seeds into the cup [above] gives you sufficient liquid to where you swirl the cup. And it’s not a problem at all to add enough water to get it to swirl well. That does not cut down on the fermentation. Just beware that the hotter the weather, the quicker of the fermentation. In the middle of the summer, any longer than two or three days and you’re starting to actually germinate the seed that you’re trying to save. So get it out of there quick.

So there’s so many different hints and tips. It’s an endlessly fascinating hobby that there is always more to learn. Last thing I’ll say, I’ve got 70 plants here [below], 115 plants elsewhere, and it is inevitable that plants are going to go down to disease. I’ve got one today that’s got pith necrosis. It’s dead as a doornail. Another with collar rot, two with Fusarium wilt.

These things are capricious. These agents are flying around, they’re landing on your foliage. They could be in the ground for the roots to pick them up.

So I think my way to get around that is plant lots of plants, so that when you start losing a few, it’s not devastating. Whereas if I just had a half-a-dozen plants and lost two of them, that’s one-third of my future crop. So it’s just a little risk assessment thing I take-

Margaret: Absolutely.

Craig: … when I decide what I grow.

Margaret: Well, Craig LeHoullier, we’re going to… As I said, fortunately for someone, we’re going to be giving away a copy of “Epic Tomatoes,” which tells them even more. And they can join your Instagram Live the rest of the weeks of the summer, and get that support that you give to all your visitors and so forth. So thank you for answering my urgent tomato questions. [Laughter.]

Craig: Well, and I want to mention-

Margaret: Our annual visit.

Craig: When you call “Epic Tomatoes” classic, it made me, Number 1, feel a little bit old, but it made me realize-

Margaret: Well, I’m old, too.

Craig: Well, we are. But it’s been out there for almost nine years now, so time has flown. Last little tidbit. I’m actually talking to my story publishing editor on Wednesday. They seem to be interested now on perhaps having me write and publish the Dwarf Tomato Project book.

Margaret: Oh, great.

Craig: So fingers crossed-

Margaret: I’ll give the link to that conversation that we’ve had about Dwarf Tomato Project. Great.

Craig: Yeah.

Margaret: And I’ll talk to you again soon. Thank you.

Craig: Thank you. This was a pleasure.

more from craig lehoullier

enter to win ‘epic tomatoes’

I’LL BUY A COPY of “Epic Tomatoes” by Craig LeHoullier for one lucky reader. All you have to do to enter is answer this question in the comments box below:

What’s your favorite tomato to grow (and do you have any ripe fruit yet)?

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, Aug. 8, 2023. Good luck to all.

(Disclosure: As an Amazon Associate I earn from qualifying purchases.)

prefer the podcast version of the show?

MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 14th year in March 2023. 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 July 31, 2023 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).