Long-time grower Steve Groff discusses no-till high-tunnel vegetable production and cover crop seeds.
Interview by Paul Meyer
STEVE GROFF is a familiar name in the no-till world. Alongside helping develop both the roller-crimper and the tillage radish cover crop seed, Groff has been farming no-till in Lancaster, Pennsylvania, for more than 30 years. As one of the longest operating no-till operations, his farm offers the opportunity to discover the long-term benefits, and challenges, of farming in tune with nature to develop nutrient-rich food. Groff is the author of The Future-Proof Farm: Changing Mindsets in a Changing World.
ACRES U.S.A.: It’s September; how are things there onthe farm in Lancaster?
STEVE GROFF: Good — things are busy here. I have 12 employees who are busy harvesting squash and pumpkins — and still tomatoes.
ACRES U.S.A.: I’m sure that’s a lot of work. You’re a no-tiller, but not just for row crops — it’s not like you can send a tractor out there to harvest tomatoes.
GROFF: No, and not only that — we’re no-tilling into 30-year no-till fields with high tunnels. I built high tunnels over my long-term no-till fields and I designed a no-till vegetable transplanter. I was on the cover of Acres U.S.A., I believe, back in 1996 or ’97. We’re still doing the exact same concept, but even more refined and intentional.
ACRES U.S.A.: How many hoophouses do you have?
GROFF: We have 3.5 acres under hoophouses
ACRES U.S.A.: Wow. Is that the total area, including the area between the houses, or the actual growing area?
GROFF: That’s the actual growing area. I have seven high tunnels that are 34- by 288-feet long, and I have them spaced 34-feet apart. So we leave the ground stakes in and we just take the hoops and move them over every three years to do a rotation. That’s 1.5 acres equivalent. And then I have two acres of Haygrove connected tunnels — multiple bays that are connected together. I also move that structure every three years to rotate it. It’s all no-till.
ACRES U.S.A.: That’s a lot of rotating of tunnels.
GROFF: Yes, but it’s worth it. You’re just fighting Mother Nature if you’re trying to grow tomatoes in the same ground year after year after year. I’ve had some fertility people who were selling products say, “Oh, we could help you out there, Steve.”
And I’m like, show me a guy who’s grown tomatoes 10 years in a row who’s getting good yields and good quality. I’d like to talk to that guy.
ACRES U.S.A.: Yeah, and at that scale, you’re not putting on compost every year. You’re growing cover crops for fertility, right?
GROFF: I am. The multi-bay ones — I can’t leave the plastic on year round because they can’t withstand the snow load. So I built the new ones heavy enough for snow loads — so I could grow cover crops in them during the winter. Our tomatoes are done by the first week of November, more or less. We can survive a couple of frosts. Then we take the tomatoes out and we plant a cover crop in there and close the tunnel down, and by Christmas that cover crop is a foot tall. We’ll open it up for a month just to get it winterized and then close it down again. In February, the cover crop starts to grow again, and then we plant our tomatoes into that. We use indeterminate varieties and we lower the tomatoes as they grow — we put them on strings and use the lower-and-lean system. The tunnels enable us to grow from the end of April to the beginning of November.
ACRES U.S.A.: Do you use drip irrigation? And what do you do for weed control?
GROFF: Yes — drip irrigation. Cover crops are our first line of defense. And then, after that, we just do some hand-hoeing and weeding. I have added additional straw to it, just to give more of a residue mat to help control weeds. But we do have to do some hand weeding. And I have a sickle-bar mower. Every couple of weeks we just run through and clip off any weeds that pop up.
ACRES U.S.A.: What’s the row spacing inside the tunnels?
GROFF: They’re about five feet apart.
ACRES U.S.A.: And what kind of tractor are you using in there? I assume you can get a driving tractor in there, right?
GROFF: To plant I can actually use my 80-horsepower tractor — if I take the exhaust pipe off and watch my head. I can pull the no-till waterwheel planter we custom-designed for this. And we can go through with a cover crop roller and roll the cover crop down. And my drill for planting the cover crop can fit in there too. And then I have a walk-behind BCS sickle-bar mower that we can put between the rows when we need to.
ACRES U.S.A.: I would think it’d be a lot simpler to just grow determinate varieties — you really push it up a notch to grow indeterminate varieties, because that’s a lot more labor.
GROFF: Well, I’m focused on heirloom tomatoes, and they’re pretty much all indeterminant. That’s what my specialty is — I have mixed heirloom tomatoes. People love my pack. And we try to stay away from the red ones. We don’t like red tomatoes — just because we want to be different. It’s been very effective. I’m not saying we don’t have a few red ones tucked in there, but we like the deep purples, the greens and the variations of the blacks — which is kind of purplish. We grow a few yellow ones and a few green zebra, which are literally green with stripes on the right. And some Roma types.
ACRES U.S.A.: Who are you selling to?
GROFF: We sell to local distributors here in the mid-Atlantic region. We’re able to command a premium because of what they are. Heirlooms are good to be grown in high tunnels because they’re protected from the rain and you can manage the water very effectively. I wouldn’t think of growing heirloom tomatoes outside. You can use drip irrigation to keep them from getting dry, but if you have a two-inch rain, they just explode and then they crack and it’s just a mess.
ACRES U.S.A.: What are you doing for nutrient management?
GROFF: Well, that’s a big question. That’s an evolving practice here. I’m trying to eliminate as many inputs as I can. I have dabbled in quite a few biological-type amendments — both through the drip and foliar feeding, and even spreading them on the soil. Since I’m no till, the biological activity in my soil is very critical.
Particularly for my tomatoes, this is why I need to have a mulch — a biomass or organic-type mulch that can feed my microbes, my earthworms, all year round, even in my high tunnels. That’s why it’s important that the soil be covered. That’s why I do not use any kind of landscaping fabric, like people typically do in high tunnels.
Next year, instead of straw — wheat straw or oat straw or whatever — I plan to use alfalfa hay. Literally, topquality alfalfa hay is going to be my mulch. I’ve heard of several tomato growers who are now doing this, and they’re seeing really good results for the tomatoes. I’m gonna grow my cover crop, I’m gonna roll it down, and then I’m gonna put alfalfa hay on. Alfalfa does have a good amount of nitrogen and potassium and things that tomatoes particularly need. So that’s where I’m headed. Talk to me in two or three years to see how it went!
In 2018, I worked with a soil scientist and came up with a very diverse mix of minerals and microbes. We got soil from my woods and mixed that in to try to inoculate the soil with the microbes that used to be in my field. I’m in Pennsylvania — Penn’s woods — my farm was all woods 200 or 300 years ago. The way our ancestors farmed either starved out the microbes or killed them — they weren’t needed here because farmers supplemented with other things.
Now, I’m not against fertilizers. I’m not against some chemistry. But it’s been way overused. And so the way I fertilize — the way I apply nutrients — is extremely important to me. In 2018 I did this experiment, and it proved to be very encouraging. We put together and applied 52 naturally based products, and that year we had very low disease pressure and very low insect pressure. That whole year I applied this product to the hightunnel land, and we just irrigated with water all year — we never added anything. I learned some things with that. I wasn’t able to replicate that exactly the way I wanted the next year, but it showed me that it is indeed possible to grow plants with the right minerals and microbes.
Minerals and microbes have to go hand in hand. If we look back to the way soil was designed to function, we use the term “biology,” but it really comes down to minerals and microbes and how they are functioning to grow plants. Clearly, as we look at nature — as we look at the woods, as we look at a prairie — somehow plants grow. It’s green. It’s lush. Somehow there doesn’t ever appear to be nutrient deficiencies, and somehow there’s very little disease and insects. So what are we missing in the way we grow food?
My endgame is to grow nutrient dense food — nutrient-rich food. I’m starting to call it food as medicine. I want to grow food as medicine. That is my goal. I’m on a journey — we are on a journey, collectively, those of us who are in this space called regenerative agriculture, or whatever name you want to put on it — to grow food as medicine. I don’t say that we need to replace all the pharmaceutical things that are out there, but I will say — as we all probably would agree — that they’ve been way overused.
When you look at our health today, as a society, we’re living longer than ever, but we’re sicker than ever.
That’s something that I don’t think many people are really putting their finger on — that, foundationally, the food that is being produced now is not as nutritious as it once was. We have to address that. I am on a mission to share the word with the world that this is what I am doing. This is the mission I have.
So I’m working with the Bionutrient Food Association — with Dan Kittredge and his nutrient-density meter. I have one here. I’m also working with that on my CBD operation. I also grow fiber and some grain hemp too — I’m experimenting with the whole hemp plant. But I’m working mainly with CBD at this point. I’m working with a major medical research facility, testing the CBD that has grown on my regenerative soils — my healthy soils. We’re using the Cornell soil health test and working with another major university on the human-health side. That CBD grown on my farm has killed cancer cells in the lab, and it’s had an influence on pain management. That’s fascinating and that’s great, but what’s greater is that we’re seeing a difference between what is grown in my best, most healthy fields compared to what’s grown in conventionally tilled fields. And we’re doing a replicated study here this year to see if we can scientifically prove that better soil will yield better-quality CBD.
ACRES U.S.A.: Have you experimented at all with sap testing?
GROFF: Yes, I’ve done some of it. Sap testing is a part of my plan. I’m still trying to learn the nuances of it. It seems like the next frontier that is going to help us fine-tune and manage growing nutrient-rich foods — food as medicine. So far I’ve just done sap testing on my tomatoes, but next year I plan to expand that. I grow 80 acres of pumpkins and squash. A lot of them are not edible — they’re just decorative — but still, all these principles apply, no matter what you’re growing. The principles you use to grow a more nutritious tomato can be applied to grow a more disease-resistant pumpkin. …
To read the full interview, purchase a digital or print copy of the January 2023 issue, or subscribe to Acres U.S.A. magazine for monthly coverage of similar in-depth interviews and educational articles on eco-farming. Learn more about Steve at stevegroff.com.