THEY’RE AMONG the most popular and good-for-you vegetables, but brassicas—broccoli, cabbage, cauliflower, Brussels sprouts and the like—can also be a little tricky to grow unless you start with the right variety, get the timing right, and have a preemptive action plan to outsmart pests.

I got advice on how to accomplish all that from Steve Bellavia, who joined Johnny’s Selected Seeds in 1993, where today he’s product manager in their research department for peppers, broccoli, cauliflower, cabbage, and Chinese cabbage. Varieties you may not have tried, like flat cabbage, or mini-broccoli, or green-stemmed cauliflower (above) might be a better match and give you better results than the most familiar versions; we talked about those and more.

Read along as you listen to the April 12, 2021 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).

best brassicas and how to grow them, with steve bellavia

Margaret Roach: Hi. Steve, and right in time: We need the help. You go to the garden center at this time of year, and we all want everything to fill up the vegetable beds and so forth. But a lot of times the starts—the vegetable seedlings, cellpacks of seedlings—some of the plastic labels may just basically say “broccoli” or “cauliflower” or whatever. They may not even have a variety name. I think we have to do better than that to have good success, don’t we?

Steve Bellavia: I think so, yes. It’s better when you can choose the particular varieties you want, to address your particular needs as a gardener.

Margaret: Yeah. So maybe let’s start with broccoli, because you say “broccoli” and people visualize the big, giant green heads at the supermarket or whatever, or the farmstand. But I don’t know, I don’t even grow those kinds, do you?

Steve: I don’t, either. They’re fine, and I liked them but the reason I don’t is—there are several reasons. One is you get one big head and you cut it and you’ll get side shoots definitely. But eventually they’ll kind of peter out a little bit. And also I think the flavor of broccoli is good, but I think there are some of the other types of mini-broccolis [above] that are better. So what I usually end up growing at home are what we call at Johnny’s mini-broccolis.

Basically they’re often crosses of a standard broccoli with an Asian gai lan or Chinese kale, which is a real small-floretted variety. And those varieties are sweeter. So if you grow these mini-broccolis we have, such as ‘Noble Jade’ [below] and there’s another one called ‘Atlantis,’ you get a smaller floret. And when you cut them, they’ll keep coming back faster.

And another thing that’s really good about those is that they can take heat a lot better than the large-headed varieties. So when you have a summer day that it’s really hot and you have long days, you’ll get a better, sweeter crop from the mini-broccolis than you will with the big broccoli.

Margaret: Right. And I’m a longtime user and love… Johnny’s has so much information, what they call the Grower’s Library. And you’ve written a number of the articles, contributed a lot to the Grower’s Library over the years, sort of expert how-to articles. And I read one recently about these different categories of “broccolis,” and some are like broccoli raab and some leaf broccoli, and like you just said, sort of more Chinese mini-type. And I mean, there really is a diversity.

And yet again, if we go to the garden center in spring to get some broccoli, it’s probably going to be the basic, larger-head kind of a thing.

Steve: Correct. And some of the ones you had mentioned, Margaret, like the leaf broccoli [or spigariello, photo below]–those you would just direct-seed and grow them like a normal green, and then you could bunch them and you could cook them or saute them in stir fries, like you would any other kind of green.

The broccoli raabs are a bit more interesting, I think, too. Those are a specialty from Italy, and they basically, you have a small floret and then it’s quite leafy around them. And they have a slightly bitter taste that may not be so good raw. But if you saute those with a little bit of garlic and oil and have them as a side dish with pasta or other meals, they’re really good. That bitterness, when it cooks, becomes quite pleasant.

Margaret: The leaf broccoli you mentioned, I’ve heard people say spig-a-rello and I’ve heard people say spig-ar-iello. I don’t know how you pronounce it, but it’s a fun plant to grow.

Steve: It is, and it’s easy. And that’s a specialty that’s particularly grown in Southern Italy. So yeah, we grow that in our trials every year and I’ve taken that home sometimes. And just like with the broccoli raab, I’ve sauteed that with a little garlic and had it as a side dish.

Margaret: Yeah. And it just, well, like it sounds: leaf broccoli. You kind of are harvesting these leaves. Eventually it does get some little florets, as I recall, but it’s really more for the greens, isn’t it?

Steve: Correct. And if you keep it cut, it’ll just keep producing greens for a long time, just like a lot of other greens.

Margaret: Right. So are some of the ones we’ve been talking about, or is it within each group, there are varieties that are better for early, when it’s a little bit cooler, or the heat of summer, or fall, as it’s cooling down again. I mean, is that a factor, too, in choosing what we want to grow?

Steve: It is for the large-size heading broccoli, definitely.

Margaret. Oh.

Steve: For the mini-broccolis, they have good heat tolerance and you could plant those from spring to summer, and all of the crops will usually do pretty well. Though of course, they’ll do a little bit better when it’s cooler weather.

Margaret: Right. So I don’t know—because we’re going to talk about a couple of other brassicas, a couple of other cousins of broccoli—I don’t know if we want to talk about growing how to, and some basic pest prevention now before we go on to the next crop. Because I don’t know if there’s some general advice that you have for us on all of them, or what would be the best way to go about that?

Steve: There is general advice. What I would say for all of these brassica crops, what I like to do on my home garden is used the spun-bond row covers to put over the crops. That will exclude flea beetles, which are really damaging, particularly to seedlings. And it’ll also take care of cabbage loopers, and other types of butterfly and moth pests that can really do quite a bit of damage to a brassica crop.

I find that to be the easiest way to control them, rather than have to go out and treat them. If you don’t use row covers, then there are many different organic products that you can spray on the crops, but you’ll have to spray them repeatedly that way. And it’s just a lot more work.

Margaret: So with the Agribon or another fabric, the spun fabric, like you’re saying, timing is everything, right? I mean, you don’t wait a week or two to put it on do you after transplant [laughter]? [Above, Agribon fabric over hoops at Johnny’s trial fields.]

Steve: After you direct-seed or transplant, you put it on the same day, and you want to tuck in the edges and then cover them with soil so there’s nowhere for the insects to get in.

And there are different weights to those fabrics. There’s a lightweight one called Agribon 15, and then there’s another one, Agribon 19. The 15 is really good for brassicas. It’ll protect from insect damage, but it doesn’t increase the heat very much. And for brassicas being a cool-weather crop, they’ll do much better staying cooler.

The Agribon 19 would be more for crops like tomatoes or peppers or melons where you want to exclude insects and also increase the temperature underneath. So the brassicas go for the 15-weight Agribon.

Margaret: So you did mention in terms of other sort of general growing advice, that’s some good pest prevention advice. But with the general growing, you mentioned the spigariello or the leaf broccoli, we could direct-sow. But with the rest, are you recommending we start seedlings. And do we do successions, and any other sort of getting started growing advice?

Steve: Yeah, generally we transplant most of those crops and the seed’s relatively expensive, so most growers do that. Also you can get the plants right where you want them in the garden. So we tend to do that; it’s more predictable.

And as far as succession planting, probably every three to four weeks is good. That’ll give you a new crop coming in when the old crop is going out. You can also go a little bit longer than that, it’ll just be diminishing returns.

Margaret: O.K.

Steve: And another thing about growing these crops, you have to make sure you give them adequate water and reasonably good fertility. Brassicas, they need water and they need good fertility to perform well.

Margaret: All right, so those are some important… And I think the pest-control thing is just—I mean, it’s almost not worth it because it all strikes me as if you’ve just put up a big flare or something saying, “Hey, brassica pests. I’ve just planted some.” I mean, really, the cabbage white butterfly for me is the biggest one that produces the imported cabbage worm as the larval phase. And that’s like, they just show up in 10 minutes [laughter].

Steve: That’s a problem here. And for us, at least where we are, the flea-beetle pressure is so high that if I were to transplant brassica seedlings in my garden at home, there’s a fair chance they get completely eaten and destroyed. There’d be no crop at all if I didn’t cover them.

Margaret: Right. So what we want everyone to know is you’re not doing something wrong if you have those pests. It’s that you’re doing something wrong if you don’t protect your crop right away, the minute you sow or transplant.

Steve: Correct.

Margaret: [Laughter.] Yeah. So what about cabbage? I mean, here’s another one where frankly, unless I want to make coleslaw maybe once or twice a year, I don’t really want a big giant purple or green bowling ball. But what about cabbage?

Steve: Yeah, cabbage, it’s interesting, because before I started working at Johnny’s, I just thought about cabbages being green and red and never really thought too much about it. But to me now it’s one of my favorite crops, once I’ve explored it more. There are a lot of different types of cabbages that can be used for different uses.

There are some of the real small green ones, which are real early fresh-market types. And those ones are great. There’s a variety called ‘Tiara’ [above] another one called ‘Farao.’ They have really thin leaves and they’re sweet. And those ones, they tolerate heat well. So you could grow those by planting them in the spring and harvesting in the summer. And you could really use them like you would lettuce in the summer. And we all know trying to grow to lettuce in the summer can be difficult. They bolt and you can get bitterness, but the ‘Tiara’ and the ‘Farao’ cabbages really maintain their sweetness very well.

Margaret: So the leaves are thinner you’re saying? So it’s not that really thick texture of a cabbage that I might make coleslaw out of, for instance? It’s not like where I have-

Steve: Because they’re a little bit thinner, because the heads are smaller, they’re quite tender and tasty.

Margaret: Oh, interesting.

Steve: And another one of my favorites, it’s called ‘Tendersweet,’ which is a flat cabbage [above]. And the flat cabbages, they’re really popular in Asia. And in Asia, they tend to cook most of their cabbage, and they grow a lot of flat ones there. They tend to have thin leaves. So if they cook it in a stir-fry, it’ll cook really fast and cook at the same rate as the other vegetables that they’re adding to the stir-fry. If you try to stir-fry a real thick-leaf cabbage, sometimes the cabbage takes a lot longer than the other vegetables.

Margaret: O.K. So when you say flat, meaning it’s not a big ball-shaped head?

Steve: No. ‘Tendersweet’ is really a flat-headed cabbage. It’s really cool looking.

Margaret: Oh, huh. And Chinese cabbage? I have hardly ever grown it and yet I enjoy it when I have it. When someone cooks with it or whatever, I enjoy it. So is that harder, easier, the same?

Steve: Chinese cabbage is similar to growing regular cabbage and it’s easier than growing broccoli or cauliflower, because Chinese cabbage naturally has some good heat tolerance. The crop originates in Asia in areas where it’s traditionally hot and humid. So you can grow Chinese cabbage in hot weather in the summer and it’ll do pretty well.

Margaret: Yeah. I can’t remember if I’ve ever, but I don’t think I’ve ever really grown it, and yet it looks so good. And as I said, I enjoy it when I do have it to eat. And then one that strikes me as really hard and that I’ve never succeeded with—and now comes in colors in recent years—is cauliflower.

Steve: Yeah. Cauliflower is definitely, I would say, the most difficult of the brassicas to grow successfully. Even the varieties that have the best heat tolerance don’t do well if heat gets really extreme, or in particular, if you get wide fluctuations in the weather, where you might have a 50 degree one day, and then the next day it’s 80. It really creates havoc for the plant and causes the heads not to form properly.

So it’s really best in the fall. But if you’re going to grow it in the spring, you have to choose the correct varieties. And just realize that if you have really a bad stretch of weather, it may not do so well.

And another thing about cauliflower is it definitely needs to have high fertility and adequate water, even more so than broccoli and cabbage do. If it doesn’t get those two things, it really won’t do very well.

Margaret: It kind of makes sense when you look at the plant and you look at what it’s trying to accomplish, if it were to perform in a peak manner. You know, it’s a pretty big undertaking, right? [Laughter.] I mean, from that little seed, you’re going to have this big head. I mean, water makes sense, and fertility makes sense. It looks like a hard job to produce that.

Steve: Right. It has to make a real big plant and then it has to produce a big head from that. So yes, you’re asking a lot more from the plant than you would broccoli.

Margaret: Right. What about the green-stemmed cauliflowers [photo, top of page]? I’ve read about them, but I’ve never tried them. What’s that about?

Steve: Yeah. Those are exciting. The green-stem types, those are also from Asia, and they also grow those quite a bit in areas that are hot and humid. If you look at them, they look a lot like a traditional white cauliflower, but if you turn them over, the stems are pale green rather than white. And the curd is usually not quite as white. It’s usually just a slight tinge of orange, and they tend to be a little bit looser. Like they get called loose-curd types a lot as well.

And there are several things that I think about the loose-curd types, the green-stem types, that make them a lot easier to grow than the white types. What I’ve noticed when we’ve grown these is that in heat or nutrient stress, they tend to come out of it and perform a lot better than the traditional white types.

And also another thing is that the florets are looser, so when you cut them from the heads, they’re a lot easier to cook with, because they’re a little bit smaller, and the flavor is also quite a bit sweeter. They’re very flavorful.

Margaret: That sounds like it’s worth a try if one wants to try cauliflower, you know what I mean? That sounds more forgiving, a little more forgiving.

Steve: A lot more user-friendly. And just, if you grow those, just recognize that when you look at the head, there’s going to be a slight yellow color, rather than white. That’s perfectly normal and O.K, and it’s not a problem.

Margaret: One of my favorite vegetables of all is Brussels sprouts [laughter], and maybe it’s just because it’s such a preposterous creature. [Above, Margaret and her sister, Marion, one Thanksgiving maybe 10 years ago with Margaret’s homegrown Brussels sprouts.]

Steve: [Laughter.]

Margaret: It’s this big tall thing, and it’s got all these crazy little satellites on a stem. It’s just a funny, funny thing. And when I succeed with it, I just feel so victorious. And also frankly, because at like the fall holidays or Thanksgiving time, I mean, in the organic market, they’re pretty expensive at that time of year. So if you’ve grown your own, you really feel like you got your money’s worth out of your seeds and then some.

So what about Brussels sprouts? Are there easier/harder ones, or is there a timing? It seems like there’s a timing with those, especially.

Steve: Yeah. I would say timing is a big issue. We like to sow the seeds in the greenhouse in May.

Margaret: Oh!

Steve: And then we transplant around the last week of May, beginning of June. I’m sorry. We sow the seeds in the beginning of May and then transplant around the 1st of June. And then that means when the crop is maturing, it’ll be doing so when the weather is cooling down. So that you’re way more likely to get a successful harvest than if you were to, say, start them in April, where they’re going to be growing through the whole, hot growing season.

And also, like cauliflower, Brussels sprouts really need quite a bit of fertility and quite a bit of water. If they don’t get those two things, they really don’t do that well.

Margaret: So just for perspective, you’re talking about a set-out date around early June. What’s that relative to like your frost date or when you’d put out, say, tomatoes or something? Is that around your frost date or is that after or before or what?

Steve: We put out tomatoes around the first week of June usually. Our frost date up here is usually right around Memorial Day or so.

Margaret: O.K. So even though Brussels sprouts are more of a “cool-season” crop because they take a long time and like to develop the sprouts at the cool end of the season, we’re putting them out when we might be putting out our warm-season, like our tomatoes or something. So we don’t want to start them too early and have them, like you said, trying to mature in like August or July or something. That’s not a good thing.

Steve: Right. They don’t mind growing when it’s hot. They’re perfectly happy. It’s when they’re starting to put out the sprouts, if it’s real hot, that’s when they really don’t like that. But if they’re starting to set the sprouts when the weather’s cooling off, you really get the firm sprouts that are real good quality. And then once you start getting some frost on them, that’s when the flavor really sweetens up and improves.

Margaret: So in the last few minutes, I wanted to just talk a little bit about some of the… I mean, as long as I’ve been gardening, I’ve been using the references—it used to be in the catalog, and then, of course, on the internet in the Grower’s Library online. Lots of information in there. And as I mentioned before, you’ve contributed to it. So kind of just give us a little bit of a tour, a couple highlights of what can we find there.

Like I love the… I have one on my site, too, I built a seed-starting calculator, when to start seeds. You have that, and lots of other kinds of videos and articles and so forth. Tell us a little bit—I think you have a planting program grid kind of a thing also that you’ve told me about.

Steve: Yeah. At Johnny’s, we like to give our customers a lot of information to make them successful too, rather than just sell them seeds. And if you look on the website, or in the catalog, we’ll have what we call planting programs.

So for example, if you pulled up a planting program for broccoli, it will tell you which varieties are suitable for transplanting and harvesting at which seasons. That way you won’t make the mistake of planting a broccoli variety that likes to mature in cool weather in the spring, and have it mature in the hot weather and be unsuccessful. So those planting programs are real helpful. We do those for cauliflower as well, and for some other crops.

Margaret: O.K. And so obviously we’ll also give some links to some of the articles that I referred to, like the one about the different types of broccoli and broccoli relatives and so forth that you’ve contributed to.

When we’re speaking, it’s early April, are you already out in your own garden yet? Is the soil ready yet for you? Have you planted anything in your garden, Steve? [Laughter.]

Steve: Not quite, Margaret. It’s getting close, but it’s probably a little wet and cool yet up in Maine. Probably in the next week, I’ll be able to poke around a little bit and maybe plant some peas.

Margaret: Yeah. That’s what I was thinking, too. It’s been mucky here and we’ve just been having some windy days. So it’s starting to dry out. I think normally I try to get the peas in earlier, but I think it’s going to be this weekend before it really feels O.K. So we’ll see.

Steve: You’re a little bit earlier than we are, you being down near Connecticut.

Margaret: Yeah, down in that direction. Well, I’m glad to speak to you and to get some advice on growing some of these brassicas, and especially the timing and the fact that selecting the right variety is so important to success. So I appreciate your making the time and I’ll talk to you again soon I hope. Thanks.

(Photos, except of Margaret and her sister, from Johnny’s Selected Seeds.)

plus: how to grow kale

• We didn’t mention kale above, so here’s the lowdown on that, from Sarah Kleeger of Adaptive Seeds

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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 April 12, 2021 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).