straw-bale garden how-to, with craig lehoullier
READY TO GROW IN STRAW BALES? I had an email one winter from Michelle, a new listener to the podcast version of my radio show, who was thinking of trying straw-bale gardening that year to grow vegetables. Michelle asked if I could invite an expert in the subject to be a guest, please.
No problem, I said, we’ll just call Craig LeHoullier—who some of you will recognize as the author of the hit book “Epic Tomatoes” and breeder of dwarf tomatoes, in particular, whose first book was actually a little how-to guide called “Growing Vegetables in Straw Bales.”
I invited him back to my public-radio show and podcast from his home and garden in North Carolina to talk about the straw bale gardening how-to’s: how to prep and care for the bales, what crops are adapted to such conditions, and more.
Read along as you listen to the February 20, 2017 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Spotify or Stitcher (and browse my archive of podcasts here).
straw-bale gardening q&a with craig lehoullier
Q. You know about all the things my readers want to know about, Craig, so all I have to do is put you on speed dial. [Laughter.]
A. Anytime, anytime.
Q. When you’ve been on the show before, we’ve told people about your garden, which is actually set up like a mini production facility in your driveway in pots and straw bales. Was that necessity–the desire to grow on your sunny driveway, and turn that area into a garden for your tomatoes and so on–the reason you got into straw bales? And how long ago?
A. The reason I got into it was really two-pronged. Number 1: Storey Publishing liked the way “Epic Tomatoes” came out, and they said they’d really like to have a book in their portfolio about straw-bale gardening, and I said, “Great.” That means I am going to try it, and fortuitously someone near me named Kent Rogers is considered a local straw-bale expert. He gardens not too far away, and he and I have been seedling friends for years. So it all worked out kind of perfectly.
But, to answer your question more specifically: The ability to take your garden to where the sun is absolutely the best in your yard, as a perfect reason for both container and straw-bale gardening.
Q. I love the sub-heading of the straw-bale book, which says: “Easy Planting, Less Weeding, Early Harvests.” Is that also what hooked you? [Above, Craig’s driveway edged in bales ready to prep and plant.]
A. Yes, and you could put three dots and also say, “sterile medium,” and being able to equate large containers with these bales of straw. So there is almost this cost-effective aspect of it as well. But like all things gardening, no aspect of gardening is for everyone, because we all garden slightly differently in very different areas and have different needs. So I think of straw-bale gardening like container gardening as two more tools that a gardener has on their belt, to be able to allow them to maximize the very space that they have, where they are living.
Q. When Michelle first asked me about the process, by the way, she actually spoke of hay bales–and I think that’s very common: to refer to straw and hay interchangeably. But are they equivalents in this case?
A. When I think of straw, I think of something that is quite rigid and often hollow. Really wheat straw is the model type of a straw—it gives a lot of structure and a lot of rigidity, whereas as hay would be more of one of the thinner grasses. Anything that’s organic will break down over time; the added utility of using wheat straw is that it allows that bale to retain its integrity and shape and support longer into the season, where a hay—like a grass—would break down more quickly, and you wouldn’t get a full season’s use out of it.
Q. Where I live, when we buy straw instead of hay—hay might be like timothy or one of the other such grasses that are slender and soft stalks. Our straw here [in the Northeast] tends to be oat.
The other thing that I have noticed because I have sometimes used hay or straw as mulch, and I get more weed seeds sprouting in the hay. Is that another negative for hay bales?
A. Not so much a negative; because the bale is elevated, a lot of the grasses that will germinate are easily plucked.
I’m glad you mentioned oat, because alfalfa, rye, barley—these are all analogous to wheat in their functional utility to make really good straw bales. Whereas something like pine—a lot of people use pine straw to keep weeds down—it’s so hard and it takes so long to break down, and there is some acidity involved when that does break down, so it’s not as useful. But even with wheat-straw bales they will sprout, and you get beautiful wheat grass growing in them. You can leave it or you can pull it out as you wish. So it’s not really so much of a bother, just an attribute.
Q. Another thing: A couple of years ago Joe Lamp’l of Growing a Greener World public TV show told me about so called “killer compost”– compost made that incorporated animal manures from animals who ate straw or hay that was sprayed with a persistent herbicide. And even after processing it in their gut and excreting it, it still had this stuff in it. [More on “killer compost.]
And people who have used straw or hay as mulch that had these herbicides still in it had problems, too. Do you have to be careful where your straw bale comes from? Are there questions we need to ask?
A. That’s probably an extremely important question, yes. You get a question right off the bat: organic, versus people who aren’t doing strictly organic growing. Straw bales would be a great technique for an organic grower, however they would want to ask that question on the source. If you have a source and they indicate that there are no persistent herbicides sprayed, I would still tread lightly, and maybe the first season go with one, two or three bales. You will know quite quickly—you’ll either put your seedlings in or plant your seeds, and if your plants thrive that year, it’s almost like the conclusion of your experiment. The results of that experiment tell you how good a source that was.
It’s not that you can’t trust anybody, but especially if you are buying your bales from a big-box store, they may or may not have complete control over the source for a given batch of bales. So it is something to be really careful about. It’s a great point.
Q. Let’s go through making a straw-bale garden. What besides straw bales do we need to acquire?
A. First you need to think about timing, because when you buy a straw bale it really has hardly any nutrients. It is almost all structure. The whole concept of straw-bale gardening is that you are putting additives in the top, and the addition of those additives with the weather is essentially starting to create a compost within the bale. That’s where the roots of your plants are going to go, too seek nutrients and water.
I give a guideline of two or three weeks minimum before planting. So if I want to plant crops in a straw bale now, I would buy bales now but it would be two to three weeks before I planted—and of course cooler weather means slower internal composting.
To help with thinking about how many bales—and we’ll get into this later with what goes in—but I usually think in terms of two eggplants, two tomatoes, two pepper plants, just to give a guideline of what the density of planting is in a bale.
Q. So in a bale I could get two tomato plants or eggplants.
A. And that’s the equivalent of two 20-gallon containers, which is really wonderful. If you think about how much it would cost in terms of good-quality potting mix to fill two 20-gallon containers, the cost of a $5 or $6 straw bale is starting to look really good compared to that.
You need a Nitrogen kickstarter to start that process of composting. If you’re not strictly organic, you could just get a lawn starter that’s essentially 29-0-4. You could get Ammonium nitrate or Calcium nitrate, Ammonium sulfate, urea. If you’re organic, or don’t like the sound of those: blood meal, Milorganite, fish emulsion, bat guano—it’s a Nitrogen source that you want.
Q. And just to be careful with the lawn ones. If you are going to use a lawn product, and you are not organic: Read that label, to see that it’s not a weed-and-feed, not containing herbicides.
A. Yes; oh my gosh. You could charge your bale up and make it inhospitable to your plants.
Then you want to get a balanced food to use after things start breaking down. Regular gardeners would know 10-10-10, or the blue stuff—or a granular organic, like worm castings, or alfalfa meal. Lots of options.
Q. So I need two forms of nutrients—one a Nitrogen boost to get things started, and one for the longer haul.
A. And it’s really quite fun. Straw-bale gardening, like container gardening, isn’t: “Oh, I’m just going to stick the straw bale there, add some stuff to the top, and then go on vacation for a few weeks.”
A. It’s not that type of gardening. You apply, you water, you apply, you stick a thermometer in. It’s a technique for gardeners who love to be out there and doing something in the garden pretty much every day.
Q. So we’ve got our straw bale, we’ve got our food (our Nitrogen and our balanced fertilizer), and we backed up a few weeks from our planting-out date. Then what do I do? Do I dump the stuff on top of my straw bale, or carve a pocket in it, or what?
A. Very simple: You apply the granular or liquid to the top, and then water it in deeply. That’s Day 1. Next day, you just water. Third day, you essentially repeat Day 1. Fourth day you repeat Day 2. You do that for about seven days, and it turns out to be about five applications of the Nitrogen. And then you just go with the balanced material and water in deeply.
Amazing things happen—if you stick a thermometer in, and let’s say the ambient temperature is 40 or 45 degrees F, once the Nitrogen has soaked in, and then the balanced fertilizer starts chewing, you could reach 120 or 130 degrees internal temperature Fahrenheit, which is essentially a compost bin that’s starting to happen.
Once the temperature backs down to about 75 or 80 degrees you can plant—you don’t want to put plants in and toast the roots with that really high, high temperature.
A. But that all kind of happens within two or three weeks. There is no problem with doing it sooner, and letting the process go a little bit slower. The bales will be there for you to plant.
Q. When it comes time to plant—will I smell something, or see something? The thermometer will give me an indication that things are good.
A. And you can reach your hand in, and it will be a little soft and pliable inside. What really blows people’s minds when they see it, is that I have my tomato plants in containers, and I’ll say I am going to plant them in the bale now—and I’ll just take a trowel and work a little bit of space in, and seat the plant in. And then I’ll just get some potting mix and work it in around the base of the plant to make it level. And that’s it; you don’t hollow out a section and fill it with planting mix; you just essentially seat your plant with its rootball and whatever planting material is attached into the bale, as if you are planting in a container or in the ground.
Then you water it in really well, and that’s really it—it’s so simple and quick to plant in a bale.
Q. Do some crops love this in your experience, and some hate it? Who loves to live in a straw bale [laughter]?
A. My experience is part what I have found, and part if you were to take 20 straw-bale gardeners in different parts of the country. Because of their conditions, they may have a different list. For me, tomatoes, peppers and eggplant, all planted as seedlings; lettuce [above] and herbs all planted as seedlings. The smallest-seeded crops are the ones that you want to start first.
The big seeds, like the squash, peas, beans—you would actually put a 2-inch layer of a nice potting mix on to your bale and water that in well, and plant your seeds right into that [below]. Then the seeds will germinate, and the roots will go into that composting straw and you will be all set.
I have had good luck with cucumbers, squash, peas, beans—it’s fantastic for potatoes and sweet potatoes, too. The trickiest crops I have found are the really small-seeded ones that once they germinate can dry out really quickly on a hot day. Of course I am talking carrots, or radishes, where the seeds germinate and you get a hot day and you can’t get water on that surface soil, and the roots may only be a half-inch deep. You can lose things quite quickly. Just cover them with newspaper, maybe, or frost cloth, or water them several times a day so those tender, tiny little seeds are growing well.
But think about growing carrots in a medium that doesn’t have rocks or clay. You can get nice, long, straight carrots.
Q. I have to say I had no idea [laughter]. I thought I’d heard everything about plants, but I had no idea that you could sow seeds in straw bales. I had seen pictures of tomatoes and peppers and eggplants—I’ve seen yours. But I had no idea that was possible.
A. And a real bonus: Let’s say you grow your tomatoes, peppers and eggplant, and at the end of the season your bales are still in good shape. Get garlic. What I do in the South, I plant garlic and shallots and leeks in the fall, and they thrive out there in the bales all winter long, and they start growing vigorously in the spring and you can harvest the most beautiful bulbs of garlics and the most beautiful standards of leeks out of your bales in the late spring—so they’re multi-use.
Q. And now you are just trying to make me jealous, because of course my bales here would be like a glacier, a brick of ice.
A. [Laughter.] It depends on the area of the country, but even if you do that or not, most often by the end of the year, the roots of the plants have worked all of the food that you have given, because like I said at the beginning this is like container gardening. You need to water more frequently; that bale is above the ground, and the sun is beating on it, and you have water evaporating from the sides.
Drip irrigation would work perfectly, or even soaker hose across the top of the bale to keep water slowly trickling in. But you get the most beautiful compost at the end of the year that you can use the following year in your beds or fill your containers with it. There is so much efficiency out of that $5 bale, that it really does belong in the tool belt of every gardener—as long as they tread slowly at first, give it a try, and see what they like. They may not like so much about it the first time they try it.
Q. And I think that’s really such as smart caveat, as with anything: You don’t want to change up your whole garden, or all your tactics, in one swoop. You don’t want to go buy 30 bales and decide you’re not putting anything in the soil. You have to develop your technique, and like you said: these are the crops that work for you, but everyone may have a different experience, depending on the fertilizers they choose, etc.
A. I found that with tomatoes, when we started selling seedlings. I didn’t want people to come and replace all of their hybrids and buy 50 heirlooms, because they don’t know how they will grow in their yards. What happens is if people try two three, four, and it works for them, then they start extrapolating out. Others may say, “This isn’t for me,” and go back to their ‘Lemon Boy’ and ‘Big Boy’ and that’s fine. Whatever works for each of us is perfectly fine.
Q. Have you noticed any difference in pests and diseases in crops in straw-bale gardening, versus in a container or the ground? Or do you ever grow in the ground, or just defy logic and only grow on your driveway? [Laughter.]
A. I would grow in my ground if I had any ground left in a place that the sun shone sufficiently on. However, one good comparison here—and that’s a fantastic question—is that in straw bales you’re actually starting out in a theoretically disease-free environment.
Many heirloom tomatoes that people cherish may have particular susceptibility to diseases, so they are a really good place to try to those tomatoes that you just haven’t gotten to grow in the ground—particular soil-borne diseases like a fusarium or verticillium. You still have to do all the same things to keep the top of the plant healthy: watching for things like early blight, things like septoria that blow in from above. But growing where you are worried about things coming in through the soil, through the roots, bales really help significantly.
Q. And you just said where some of these diseases are present in the soil—so that doesn’t mean that someone has a “bad” garden or has done a “bad” thing. These issues are living in our soils in some regions of the country. Like when people see a tomato rated for resistance to VFN …
A. And they have for like 150 years. If you look back in old, old seed catalogs, the problems they describe were things like verticillium wilt or fusarium wilt or nematodes. We’ve not done a very good job of eradicating them, so what we have to do is find workarounds that allow us to enjoy these crops. Straw bales are a nice workaround.
Q. Because it’s sterile compared to the soil, when you bring it home—and provided it’s not laced with persistent herbicides, which we must be careful to avoid—but it’s a clean medium.
A. And you will see interesting things happening, like mushrooms.
A. And they’re very darkly colored, and I found out that they are the mushrooms that they extract the material that Antabuse is made from. So they even have a biological use, and I know sometimes out gardens lead us to drink too much beer if they’re giving us trouble. [Laughter.] But they just go away; they come up on a damp morning, and then the sun comes out and they kind of melt.
It’s a beautiful process, and fascinating to watch. Let’s say you plant bush beans, and the top of a straw bale is a couple of feet off the ground, that means you can pull up a chair and pick your beans, rather than bend over and get the sore back. So that elevation is good, and you don’t have to fill containers with potting mix—there are some labor-saving instances to using straw bales.
Q. I just want to double back to when we’re getting started, and I have all my materials and am going to prep the bales. We talked about on Day 1 and again on Day 3 and so on, that I will add my high Nitrogen. I know every product is different, but based on what’s on the fertilizer label, how do I know how much to add?
A. It’s not terribly precise, but what I did is I used guidance from the internet and from previous books as a start. And anybody can email me at nctomatoman [at] gmail [dot] com and I am happy to let them know more. [Above, Craig’s chart from his book, on the high-N fertilizer equivalencies to prep the bale.]
more from craig lehoullier
- Craig’s website
- Craig and Margaret talk “Epic Tomatoes”
- Craig and Margaret talk about best heirloom and dwarf tomatoes
- Craig’s books on Amazon
enter to win craig’s straw-bale book
I’LL BUY COPIES of Craig LeHoullier’s little guide to “Growing Vegetables in Straw Bales” for three lucky readers. All you have to do to enter is answer this question in the comments box, all the way to the bottom of the page, after the last comment [UPDATE: This giveaway is complete.]:
Ever tried straw bales–and if not, do you think you might try (if so, with what crop)?
I’ll pick the random winners after entries close at midnight on Tuesday, February 28, 2017. No answer, or feeling shy? Just say something like “Count me in” and I will, but a reply is even better. Good luck to all. US and Canada only.
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 10th year in March 2019. 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 20, 2017 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).