success with brassicas (including brussels sprouts), with don tipping
THE OTHER DAY as I was plotting who I could ask for help outsmarting the coming season’s cabbage worms, and coaxing the Brussels sprouts to fatten up on time for holiday meals, I got an email from organic seed farmer and breeder Don Tipping of Siskiyou Seeds in Oregon.
You might remember Don from his last visit to the program, when he taught me how to grow onions like a pro from seed, one of the most popular subjects ever on my show and website. Well, apparently Don had somehow heard what was on my mind, because he wrote to suggest a conversation about what he calls Brassica success tips. Serendipity.
Don Tipping has been growing and selling wholesale seed on his farm called Seven Seeds for about 20 years, and in 2009 started a retail seed company as well, Siskiyou Seeds, offering his own seed and also the best varieties from a number of organic seed-farming friends. Don also hosts a five-day Seed Academy each spring, teaching farmers, gardeners, and others to have success with seed, breeding, propagating, growing, harvesting, and saving.
On the subject of Brassicas, we talked about things like this:
- How thinking back to the Mediterranean origins of the plants gives some clues to success.
- Why stingy soil volume in tiny cellpacks doesn’t suit the likes of broccoli, cauliflower, Brussels sprouts.
- How to satisfy these hungry crops naturally, so they thrive.
- What to do to try to outsmart flea beetles and cabbage worms.
- What in the world a “tree collard” is and who can grow one.
Read along as you listen to the Jan. 22, 2018 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
growing brassicas, with siskiyou’s don tipping
Q. It’s so nice that you could read my mind. Thank you, thank you.
A. You’re welcome.
Q. Great minds think alike about Brassicas, right?
Q. It looks like, from your updated website and all the new offerings, like there’s a whole selection of organic flower seeds, I think, that are a specialty of your partner, is that correct?
A. That’s right, Yes. My partner, Stacey Denton, has been a farmer-florist for about a decade, and I invited her to let her love of flowers shine through, in terms of our seed offerings, as we’ve always grown a lot of flowers on our farm for pollinator habitat, or just the beauty that they bring. But there’s quite a resurgence in the desire to grow organic, local flowers, so that whole concept around local food is extending to flowers, and we wanted to be able to support that by having the choice varieties that farmer-florists are looking for. [Above, Don and Stacey.]
Q. Yes, and gardeners. And gardeners, too.
Q. I wanted to get right down to the promised Brassica success tips, because between timing and pest control, I know a lot of us gardeners really need the advice. So, first, the word Brassica–and some people say Crucifer, or Mustard family–it’s a lot of different things that we grow, isn’t it? It’s not just broccoli or anything. It’s mustards, and …
A. Yes, it’s a huge family that includes everything from radishes and rutabagas, to broccoli, cauliflower, collards, kohlrabi, and then a lot of oddballs, too, like arugula, that we may not normally associate with being a Brassica.
Q. Yes. I think even horseradish is in the family, and you can kind of tell when it flowers, it looks a bit alike, doesn’t it?
A. Yes, that, and another one that would be like that is Persian cress.
Q. Oh, I don’t know that.
A. Some people call it penny cress, because the seedpods look like little coins.
Q. Oh, neat. In some of these there are hybrid and pollinated varieties, but you grow open-pollinated varieties, yes?
A. Correct. Everything that we offer and that we grow for seed on our farm is all open-pollinated, which for me has been a bit of an intentional choice, because then anyone who wants to can actually save seeds from what they get from us, and I really just believe in that whole idea of being open-pollinated, as a business model and for my own self.
Q. Right—ethically, yes.
Q. Some of the Brassicas seem really easy to grow, like to just direct-sow, almost. I’m speaking as a home gardener, not as a farmer and seed breeder, but like arugula or radishes, or even the mustards, I feel like I can practically treat them as I do other salad-y sort of things, and just direct-sow them. But sometimes I get flea beetles, and other things that give me problems. Is that a problem out there, too, in Oregon?
A. Yes. Well, and I think, to take just a little step back and look at the Brassica family as a whole, we know through the recent popularity of kale, in terms of people using it in green drinks, and just adding to their diet more than perhaps they did a decade ago, that the whole Brassica family has a lot of nutrition. That nutrition comes from the soil, obviously, but it also makes it a bit of a target for pest insects—everything from slugs, you mentioned flea beetles, and cabbage moths, and cutworms, you name it, because there’s a lot of bang for your buck, so to speak, in eating those plants. And they don’t have a lot of the defenses some other plants may have to make them unpalatable, or uninteresting to pests.
As a gardener, you have to consider that and take measures to avert damage, so you can get a crop organically. For us, like flea beetles, you mentioned, one of the things we’ve had to do is use floating row covers, and we’ve found that can be really effective. Spun polyester, if people aren’t familiar with that.
Q. Yes. And do you put that on when you sow seed, before it even emerges, or what? When do you put down the cover?
A. There are different approaches you can take. Some of the mustards, like the Brassica rapa, that includes tatsoi and mizuna, Chinese cabbage, Napa cabbage, and turnips, actually, they’re what I find the most attractive to flea beetles, because they’re the most tender. They don’t have any of the spicy compounds. So, when we grow that as like a salad-mix crop, we’ll seed it, direct-sow right in the ground, and then cover it right away, because if you let the flea beetles build up a population, it’s really difficult to do something about it, and they don’t seem to have many natural predators. [Below, Siskiyou’s ‘Osaka Purple’ and ‘Mitzuna’ mustards.]
Q. No, they’re really tough here, too.
A. Yes. Whereas I’ve found the Brassicas that have that more waxy coating, like broccoli or cabbage, in general that would be the Brassica oleracea crops, they tend to, once they get up and going, they can resist predation by pests better than the more tender ones. But even still, when we’ve grown kale, we’ve had significant flea beetles, and for folks that aren’t familiar with that, it can just riddle the leaves with all these tiny pockmark holes.
Q. It’s still safe to eat, folks, but it doesn’t look too good if you’re serving it to company.
A. Yes, this is true. Yes.
Q. It looks like hell, really. Now, I mentioned a few—arugula, radishes, mustards. I might just direct-sow them as a home gardener, in my raised beds, a short row of each one, frequently. But I think you do a lot of transplanting of starts sown in the greenhouse, and I do that with other things in my house, under grow lights. Do you sort of lump together certain Brassicas into groups of when you start them, and how you start them, and how long they’re indoors, and when they go out? Is each one distinctive, or are there some groups we could talk about?
A. Yes, in terms of the above-ground crops—we’ll leave out the root crops like rutabaga and radish for a moment. I lump them into salad crops, like you mentioned—arugula, and the mustards, raab, things that you would cut repeatedly for salads and such—as opposed to the crops where you’re getting more of a head, like broccoli, cauliflower, cabbage, kohlrabi.
A. So, those two categories would be salad crops—they would be the direct-sown ones—and those heading types would be what I grow transplants of. And something like a broccoli, if you’re not getting a head, there’s not much value to the crop, whereas an arugula plant, if it doesn’t get huge, you’re still able to get some leaves off of it. So, that’s where I see the extra effort behind making transplants and babying them indoors—however you do it, under lights, or in the greenhouse, or a cold frame, is worth the effort—because you want to get a crop.
Q. Right. So, do you back up like, a month, or six weeks, for indoor time with those? What’s your sort of formula-ish, in terms of timing and length of time indoors?
A. Well, we’re not using artificial lights of any sort, so coming up soon in Oregon—February first—is when we’re going to do our first feeding of broccoli and cauliflower and so forth. So you can think, the daylength is shorter. If you’re seeding, say, April first, they’ll grow more quickly, and you could have transplants ready in a month. I would say from our February first planting, it’s not going to be until six to eight weeks after that we’ll actually be transplanting those out.
And that’s where I think this is an important thing to consider: because the Brassica family is a fairly nutrient-intensive crop, it wants a lot of Nitrogen so it can grow quick, I’ve found if you don’t have adequate nutrition, the plant get stunted, and it can just never really thrive.
Q. Oh, boy, have I had that experience, Don. I’ve had that in a couple of bed where I didn’t know why. [Laughter.]
A. Yes. It shows up as tiny heads, or just a very unfulfilling gardening experience. So, by supplying adequate nutrition—we really just use compost, but we may do some kind of foliar spray with fish emulsion, or kelp, or something to help nurture them along. And also, in terms of if you’re doing starts indoors, making sure you’re giving the plant enough room for its roots. A rule of thumb that we use is, each cubic inch of soil is enough fertility for one month.
Q. Oh, O.K..
A. So, if the plant is in there longer than a month, you need to begin to augment that, with either some kind of liquid fertility.
A. Fish emulsion works great for that.
Q. So, in my climate, where our frost-free date is maybe more like mid-May, or third week of May, something like that, and I think I can put these cool-season guys, like you were just speaking about, cauliflower, broccoli, I think of putting them out maybe two, three weeks before the frost date. Maybe even a little earlier, maybe four weeks, I don’t know. I might start them for six weeks inside. That’s my sort of rough … So, it’s the same thing, but in a different part of the country. You have a greenhouse, natural light. I’m doing them under light in a warmer environment, as if it’s later, so to speak. But the formula works out either way, I think.
A. Yes. And for us, for broccoli, cauliflower, cabbage, Brussels sprouts—that clan, if you will—my favorite, if I’m thinking about it from my home-garden perspective of really wanting to get food out of it, then my favorite sized pots to use for starting them are actually fairly large. They’re about 2 inches square, and about 3 inches deep.
Then you get a really healthy, large transplant, so when you put it out, the plant can afford to lose a couple leaves to pests, or slugs, or what have you, as opposed to smaller starts, where if it loses a little bit, it’s going to be really stressed.
Q. Well, and sometimes you see them in cell and traditional six- or four-packs in the nursery, and they’ve already started to sort of stretch; they look spindly. You know what I mean? They’ve lost a lot of leaves, and it’s like, oh boy, that guy’s not happy. And so you’re saying, it would have liked having double the amount of soil volume and nutrition. [Above, ‘Snowball’ self-blanching cauliflower and ‘Red Express’ cabbage.]
Q. O.K., good. So, not so many people that I know grow collards as they do kale. Do you find that out there, too? Is it more kale than collards?
A. Yes, I do, but we’ve been growing some seed for a company that’s in Virginia called Southern Exposure Seeds.
Q. Oh, and I love them for many years. Yes, of course.
A. Yes, and they’ve really opened my eyes to the incredible diversity of different types of collards. There’s one particular type that we just started offering through our seed company called ‘Cascade Glaze,’ that was actually bred by Carol Deppe, who’s an Oregon plant breeder here.
Q. Yes, we’ve had her on the show, she’s great, sure.
A. Yes. So, instead of that blue-green waxy look, this actually has a shiny, light green color to it, and I guess in the Southeast, they call them greasy collards. [Above left, ‘Cascade Glaze’ collards; right, ‘Alive Vates’ grex kale.
Q. They still call everything greasy there, don’t they? Greasy beans. It’s so funny. [Laughter.]
A. I mean, maybe that has to do with your cooking technique.
Q. The fatback.
A. But from what I understand, and I’ve never really done side-by-side trials of how kale holds up over the heat of the summer versus collards, but from what I gather, collards are more of a heat-adapted way to have greens through the summer, whereas I know for us out here in Oregon, we can get up in the upper 90s or even over 100 come July or August, that that really brings aphids to our kale. And the plant seems to still grow and be fine with it, but it means a lot of washing when you want to prepare it as food. And collards tend to have less of the savoy, the wrinkly-ness of the leaves, that are the best places for the aphids to hide, on the flat leaf, so even if they do get some aphids, it’s easier to wash them off.
Q. You even have this tree collard, which is sort of a different beast all together, which was kind of hilarious on the catalog I saw, that you sell as transplants. You sell plants of that, yes, not seeds?
A. Actually, cuttings of that.
Q. Cuttings, O.K., cuttings, Yes.
A. Yes, and one of my mentors, Doug Gosling, who he’s managed the gardens at the Occidental Center for Arts and Ecology for 30 years, he exposed me to this, and they had one plant that was, I would say, 8 feet in diameter.
Q. Oh my goodness. [Laughter.]
A. And the stem would grow up, and bend, and fall over, and re-root farther out. It just was this whole jungle of collards. So I took some cuttings from that years ago—basically it’s just stems that are about the diameter of your thumb—and you put them in a gallon pot of soil, and they grow roots, and it just becomes this … Yes, I don’t know if it would work in the Northeast where it gets really cold, but for us, we’re in Zone 7, and it really only gets down to about 20 degrees Fahrenheit in the winter. And they’re just unstoppable, really. [Siskiyou’s tree collard cuttings.]
Q. Yes, fascinating. I’m going to have to learn more. I’m going to look up more about the plant. But we have to make time to delve into Brussels sprouts, because I see some listings in the different catalogs, and they’ll say, this is a mid-season one, or this is for late fall harvest, or this is an early one. And I see maturity dates from 100 days, 110 days. I’ve even seen the ones that supposedly overwinter, like I think you can in some parts of the country, in the Northwest, you can overwinter them. They’re 200-something days. All kinds of different numbers.
I’m kind of like, what am I trying to do, and how do I time it so that I can have Brussels sprouts more than one minute, you know, in the garden, if I’m lucky, right? Help me with those. [Above left, ‘Steve’s Select’ broccoli; right, ‘Darkmar’ Brussels sprouts.]
A. Yes, well, first, just to address the days to maturity point. As a seedsman, I kind of wish we would do away with those numbers, because it really depends on when you plant it, how well you take care of it, how your climate is, and so forth. So, for a broccoli, for instance, it may be advertised as a 70-day broccoli, but that’s really from transplant. You may have six weeks indoors, and then you transplant it, and then 70 days later, you have it.
So, again, those Brussels sprouts, I find that for us in Oregon, you grow them as a spring crop, they grow over the summer, and they’re a full-sized plant that’s developing Brussels sprouts around the fall equinox, and then you’re able to start cutting it sometime after Halloween, and they’ll hold in the field. As opposed to a fall cabbage, or fall cauliflower, where you’d actually be seeding that in the midsummer.
In order to grow the plant, Brussels sprouts, I view it as a 120-day crop, so that’s four months, and if you don’t get it going in the spring—like if you try and plant it as a fall crop, it’ll look like a collard, it won’t ever make Brussels sprouts, or you’ll have really small ones, the size of a dime.
Q. I’ve seen that, too. And sometimes I have great ones, and sometimes not so, and I noticed that, well, what am I doing wrong? So, you’re saying that we start it early, but were expecting to be there for the long haul, so we probably need to take really good care of this plant, and probably give it a good spot as well. We can’t neglect it, right?
Q. It’s got to have good nutrition, probably, too, and so forth. Because it’s going to try to create all those sprouts. I mean, it’s a lot of work [for the plant], it seems like.
A. Yes. And I think with a lot of these Brassicas, it’s worth taking a step back and just considering, they all evolved around the Mediterranean Sea. And you could imagine, they were plants that they made seeds—how they started, as their wild ancestor—sometime in the summer, with the warm Mediterranean sun. They dropped that seed, and then as the fall rains would come, they would sprout and grow through the winter, through the spring, and then complete their life cycle like that. So, it was very day-length dependent.
You can think, here in the northern latitudes, come September, the days are getting much shorter—equal day and night, really. So, if you haven’t sized the plant up before then, there’s just no way there’s enough sunlight, no matter how much water and fertility you give it. That’s a really important consideration—is that we’re having to use biennial Brassicas, you need to have the way we cultivate it coincide with its ancestral life cycle.
Q. I see.
A. And I think just a little meditation on the Mediterranean climate, no matter where you are growing, will reveal how to help that plant thrive the best.
Q. That’s a completely different way to think about it. That’s good. I like that.
Do you harvest, with the Brussels sprouts, do you top them at some point? I’ve read, oh, well, you’re supposed to have topped the plant, Margaret. Do you know what I mean? Tactics to get it to sprout up, so to speak, make the sprouts?
A. Yes. I’ve never done that—
Q. Me, neither.
A. …but I will go through, and I’ve noticed diseases and pests will kind of attack the lower leaves. So I will strip off those leaves in the fall as I’m looking. A lot of it is just kind of taking a moment to be like: hey, what’s going on over here? Let’s get all these dead leaves off the plant and see what’s happening. Because you’ll see the little buds where the sprouts will be developing [above], because they basically form on those leaf scars as the plant grows up the stalk.
So, it starts off low to the ground as a mound of leaves, and then it elongates, and that elongation really is taking place between the summer solstice and the fall equinox, so again, just thinking about that life cycle, it’s responding to the shortening of the day length.
I don’t top it because I think, well, Brussels sprouts, again, we’re eating them for the nutrition, and they’ve got to have some leaves. And if they don’t have any leaves down low, how are they doing what they do?
A. But also, thinking about all those leaves that it has to make, just making sure it has plenty of compost. So, if you have limited compost availability, you might want to portion more of it for your Brussels sprouts than other things, or a side-dress would be an appropriate thing. We do that with celery as well. Some crops just have higher nutritional needs, and if you really want to be successful, that’s how to approach it.
Q. So, mid-growing season, you’re side-dressing, you’re adding some more compost to the sides of the rows, or are you doing that right when you’re planting?
A. Exactly, we’ll just go through with a shovel and kind of sift it along the sides, and sometimes even hoe. We’ll do that before we weed, and then the hoeing action will kind of incorporate the compost into that top layer of soil.
Q. I’ve got to ask, because I promised it at the introduction, do you have sort of garden sanitation processes, or other tactics for cabbage worms? Here in the Northeast, we have both the imported cabbage worm, the green one [below], and the cross-striped, sort of bluish, strange-looking one, purple-y gray [farther below].
Q. Anything we can do tactically when we’re thinking about growing these Brassicas this coming spring, to sort of thwart that, or in terms of garden sanitation?
A. Well, one thing that I’ve gained a lot of value from in my life is thinking about a concept that my friend, Dr. Lindsey du Toit, who’s a plant pathologist in Washington, shared with me, of the green bridge. Thinking that these pests, they have a life cycle. In order for them to be present, they have to have something to live in year-round, so if you always have Brassicas in your garden, then the pests can go from one plant to another, to the next, forever.
So, breaking that cycle. Instead of just letting the Brassicas you’re done with rot where they are, pulling them up and putting them in the compost, so that you keep sanitation that way. I don’t think you need to be excessive about it, but I have found that they want to find … It’s kind of like lily pads, if you will, that they need to hop from one to the next. And I noticed, too, that they tend to be worse in some years than others.
Q. Here, too.
A. I’m not entirely sure why that is, but I also think that the cabbage worms are very soft, juicy morsel for a meal for some other insects, or birds,
Q. Birds, yes.
A. Or for something else. So, thinking about the habitat in your garden, are there beneficial insect-attracting plants, or people use the term “beetle banks,” or all sorts of things. Rove beetles will eat slugs, and cabbage worms, and other caterpillars.
Q. I have to get me some of those. [Laughter.] Thank you again for reading my mind, as I said at the beginning; always welcome when you do so.
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. 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 Jan. 22, 2018 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).