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Marc Plinke | Powering Hyper-regional Food Production Through Greenhouse Solutions

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With rising food costs, security issues and more all around the globe, more communities and individuals are starting to think about growing their own food. As it stands, simple solutions sometimes seem too far off. What about pests, water use limits, winters that are too cold and without enough light and summers that can be too hot and dry? How do we tackle these challenges? How do we grow a garden in our own home state or near our homes that can support the community? In this episode, you’re going to learn why design decisions matter and how an engineering background and a balance-oriented mindset can help. To talk this through, we are joined by inventor Marc Plinke, who spent the past decades applying his engineering mindset and expertise to building better greenhouses. Marc started Ceres Greenhouse Solutions to help enable people to grow their own food sustainably all year round. Tune in to learn more about his work!


About Marc Plinke

CMBB 164 | GreenhouseMarc Plinke is an inventor-innovator who started his career as a chemical and process engineer at the makers of Gore-Tex, a fabric you’ve all used in rain jackets. When he landed in Boulder, Colorado, he retrofitted his family’s 1960s ranch house into a Beyond Net Zero Energy home. That experience led him to his second career in green building design. He spent the past decades applying his engineering mindset and expertise to building better greenhouses. Mark started Ceres Greenhouse Solutions with the intention of enabling people to grow their own food sustainably and year-round. His passion is his family, beliefs and leaving the world a better place for his kids and all of ours.


Guest Links:






Additional Resources Mentioned:

How Regenerative Farming Can Lead To Healthier Living With Mollie Engelhart – Past Episode

Minisode: Introducing Paul Hawken + Regeneration – Past Episode

Regeneration: Ending the Climate Crisis in One Generation

Part 1: On Building A Global Place Brand And Regionalized Food System With Steven Cornwell – Past Episode

Plant-Based Recipe Superfoods Superlife Supplements Women Reach For Your Superlife: Why You Should Count Plants Not Calories With Kristel De Groot – Nutrition Without Compromise Podcast Episode


Show Notes:

00:15 – How Marc built a Beyond Net Zero Energy home.

05:09 – Helping people produce their own food.

17:40 – Perfecting a good greenhouse design.

27:43 – Greenhouses and traditional farming.

33:00 – Pushing for hyperlocality.

41:00 – Greenhouses and the pest problem.

53:13 – Food and society.

01:00:54 – A holistic approach.


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Marc Plinke | Powering Hyper-regional Food Production Through Greenhouse Solutions

With rising food costs, security issues, and more all around the globe, more communities and individuals are starting to think about growing their own food. As it stands, simple solutions sometimes seem too far off. What about pests, water use limits, winters that are too cold and without enough light, and summers that can be too darn hot and dry? How do we tackle these challenges? How do we grow a garden in our own home state or near our homes that can support the community that isn’t ravaged by rodents as I experience in my own yard?

In this episode, you’re going to learn why design decisions matter and how an engineering background and a balance-oriented mindset can help. To talk this through, I’m joined by Marc Plinke. He is an inventor innovator who started his career as a chemical and process engineer at the makers of Gore-Tex, a fabric you’ve all used in rain jackets.

When he landed in Boulder, Colorado, he retrofitted his family’s 1960s ranch house into a beyond-net-zero-energy home. This is a dream of mine. The day I can get to net zero is one I will celebrate. That experience led him to his second career in green building design. He spent the past decades applying his engineering mindset and expertise to building better greenhouses. Mark started Ceres Greenhouse Solutions with the intention of enabling people to grow their own food sustainably and year-round. His passion is his family, beliefs, and leaving the world a better place for his kids and all of ours. Join me in welcoming Marc Plinke. Thank you for joining me.

It’s nice to hear you speak calmly. I’m not quite feeling that calm, but I’m sure we’ll settle in.

Maybe we can get amped up. I wanted to start by learning from your experience of converting a 1960s home in Boulder, Colorado, into something that could truly be net zero. What inspired you on that path? How long did it take? Tell us the story.

I had the dream of being net-zero or living a net-zero life as it started in 1973. I was twelve years old. There was the time of the first oil crisis. It started in the Arab-Israel war at their very time. The OPEC decided not to deliver any oil to the US because they supported Israel. All of a sudden, there was a spike in energy prices and there was not enough oil in the world. In Germany, a country which loves their cars and going on the Autobahn, nobody was allowed to drive.

What happened impressed me. I was standing with my dad, and I knew exactly where it was, and on which street, and we looked down at the street. There were no cars, which never happened. At that very moment, I decided, “This is a world that has finite resources and I need to do something to minimize the use of those resources.” I have been working towards that goal ever since. I always wanted to live in a net-zero house but didn’t have the resources. It took me 25 years to get there after finishing my PhD in Chemical Engineering.

This is a world that has finite resources. We need to do something to minimize the use of those resources. Click To Tweet

I did it right. I wanted to use an existing house. Not a new one. That would have been too easy. I try to do everything I can to make something more energy-efficient. That includes adding a lot of insulation, which is the easiest, windows that are quadruple clays, solar radiance, flooring, PV panels, and everything that I could do to reduce the energy use of the house. It was super fun. It’s one of those things that any engineer could dream about and say, “This makes sense. When we were done, we were probably one of the ten most energy-efficient houses in the US for old houses that used to have an energy bill of $600 plus per month.”

I put solar in my home here in California. At the time that I put it in, we were advised to cover 85% of our energy use. I said, “Why?” The price ticket was such that I’m like, “We’ll start there. We can always add panels later.” What happened is our lifestyle changed. I started working from home. I had two children. Now we are paying each month. We do what we can to limit our energy use, but it is hard to get to the place where you’re at a net zero.

I commend you for that. I’ve spoken to a few other people who have taken old homes and done something similar, but usually, they were in a space that had fields around them so they could essentially put a solar farm on their property to account for seasonality issues, battery backup storage, and things along those lines. Is that similar to you? Did you have enough space to put essentially a solar farm on your property?

We’re in Boulder, Colorado. There is not a whole lot of land anywhere. The front yard was clearly set aside for my children to play and the neighbor’s children. We love to have lots of kids there and play soccer most of the time, volleyball, or whatever. That was not an option. It had to go on the roof. I did create an extra structure on the north side of the house where I could mount the solar thermal panels, which are the hot water panels. With those two things, I could get there quite easily. When you have enough insulation, you have to design your house or your system set up correctly. That is relatively easy.

It’s interesting that as you opened the conversation, we were talking about conflict in Israel and how it affected other parts of the world. We now have conflicts around the globe that are affecting the food supply beyond what has been happening with the Israeli war. Think about Ukraine, which is called the Breadbasket of Europe, and how it’s affected food supply throughout Europe. I know part of your motivation behind this entire endeavor with Ceres is to essentially control for that and help communities be able to grow and procure their own food as opposed to relying on resources that are far away.

If you think about an apple, most of us in the United States are consuming apples that are grown in Washington. They’re kept in cold storage and shipped to us when it’s time, but there are even species of apple that do quite well where I am and you are that we could be moving towards this regionality in a broader foodscape. I realized we’re not talking about greenhouses for orchards. I’m trying to make it real so people can understand they can have something like a greenhouse that you would work to create that can feed their community. Can we talk about why you started Ceres and what you’re capable of doing?

I have to admit I was ignorant my whole life. Before this house project, I was thinking about energy use in terms of cars, power plants, and everything related to living until one of the consultants helped me pick the right windows for my house on the east side, it has different windows and on the west, south and north all are different for a different reason, light transmission and all of this. I wanted to be extra fancy.

This guy walks up to me. His name is Larry Kinney. He said, “You have a plug-in car and an energy home. Where does your food come from?” That was 2009. I was perplexed. I wanted to say the grocery store, which I knew was the wrong answer. Mollie Engelhart would be turning around and kicking this guy in the behind.

You’re referring to prior guests who have an organic reserve restaurant.

I was completely unaware of what the effect of the food supply on energy usage and CO2 emissions was. I feel very embarrassed to admit that, but on the other hand, I am proud enough to say, “I have learned a lot since then and am somewhat educated.” I cared about the environment. I didn’t know that. It felt bad, but I had sold my last company before that. I said, “I would be happy to help you build some greenhouses.” He got money from the US Department of Agriculture to build the most energy-efficient greenhouse.

We build it ourselves. It’s 1,000 square feet. It was an awesome experience, and then the idea came, “We need to build these things in people’s backyards,” and we did. I started to write in 2009 and not until the time of the cannabis legalization in Colorado did people want to listen to me at that point when I said, “We have a much more energy-efficient way to grow anything.” People said, “That’s great. Show me and build me one for free so that I can test it and see if it’s good.”

Traditional farmers tend to be a little on the conservative side and it’s like, “We have all these salespeople telling us all these things,” I want to see it. The cannabis people came from a business background and you could give them an energy calculation and say, “Here it is.” They did. It worked amazingly. We built the first greenhouse that was commercial in Colorado that was at 10,500 feet altitude, which is quite cold. It’s the highest town in the US.

It’s near where my mother lives. My family is up there.

This wasn’t a town of Leadville. They needed to build a building that was, by code, as efficient as any other commercial building. When you know greenhouses, it is next to impossible, but we were able to do that. All the things that we have learned from a few years of building backyard greenhouses let us grow half the first commercial building, which was not big. It was only about 3,000 square feet or 300 square meters for the people who are not necessarily US citizens.

From there, then came the explosion that all of a sudden, all these people wanted these greenhouses. We cornered a part of the market that was not occupied before. It means there are big grasshouses that are built all over the world. This market is owned by the Dutch. They have been building greenhouses forever. The Dutch and British were the first. The Dutch have perfected that to the degree that they can build multi-hectare greenhouses for prices that nobody in the world can touch. They own the market.

In the US, we had some manufacturers that also looked at bigger properties. These big greenhouses are completely necessary to supply big cities with food, no doubt if you want to do leafy greens, even tomatoes. Most of Europe is fed by these big greenhouses. In the US, they are built the same around all the big population centers. That’s necessary. There is a market out there for people who want to grow food locally. This means that smaller communities, cities, and towns that are 10,000 people or maybe 50,000 that are far away from everybody else.

CMBB 164 | Greenhouse
Greenhouse: There is a market out there for people who want to grow food locally.


In towns, you only get food deliveries to the local supermarket once a week. That is not uncommon. Most Europeans would probably look at that and say, “What? That’s not possible.” In the US, that is quite possible. We have food deserts not only in inner cities but in many rural areas where the farmers are farming and they have nothing fresh to eat. They have to drive hours to get to the next supermarket. They can use greenhouses, but in the US, unfortunately or fortunately, the weather is quite extreme in the summer can be easily over 100 degrees or 40 degrees Celsius. It can also be minus 20 or 30.

At that stage, a greenhouse becomes incredibly difficult to operate you can fly in your tomato for Mexico because the amount of energy that it takes in the traditional greenhouse to heat it in the winter doesn’t make sense economically and from the CO2 grounds. We could build greenhouses that can grow those crops in that climate all year long with only using a fraction of that energy and that’s what we’re after.

For readers who are curious about how this works, my vision of a greenhouse, when you talk about Holland, I’m probably thinking automatically of flowers growing like tulips or something like that. I know you’re talking about food, but I’ve seen large greenhouses that are growing bouquets of flowers. I’ve seen greenhouses that are growing things like string beans, tomatoes, and some other green leafy vegetables, but because I’m in California, most of our growing is outside.

We have a fairly mild climate here. We have growing seasons that are quite long. We do truck in strawberries and other berries for a few months of the year from Mexico, but most of what we consume here is grown in Watsonville or Salinas. It’s nearby. I haven’t seen what you’re talking about when you say this greenhouse in Holland which is very large versus what you’re doing. Can you describe the difference? What makes this unique?

Traditional greenhouses are big glass boxes. In most places, they’re with a singular layer of glass. They are multi-hectare, which means hundreds of thousands or millions of square feet of greenhouses that are fully automated. There are almost no people in there. The crops will be harvested these days even by automation. You can run 3 or 4 people that are only needed to grow enough food to feed a small city. In our greenhouses, we believe that this system is not quite sustainable because you have to use an enormous amount of energy to heat that greenhouse to keep it at the temperatures that your crops need. With lettuce, you only need about 50 degrees, which is fine. You could go a little lower. Tomatoes, for example, are common greenhouse crops.

That’s why it’s called hothouse tomatoes.

In those greenhouses, you cannot grow tomatoes in the winter. It’s way too expensive. What do we do? We buy most of our tomatoes out of Mexico. Here in Colorado and in most places in the US, we do. They get picked green. They shipped here. They will get put into an ethylene chamber where they get ripened, painted red, and then put on your supermarket shelf. Those tomatoes you can recognize quite easily. They have this little translucent color and more or less no taste, but they are tomatoes.

They didn’t ripen on the vines. Their flesh remained more dense.

The trick of a good greenhouse design is to take what nature gives you for free, mostly sun, in this case, into temperatures depending on what you need. Use that together with appropriate technologies to make sure that you get the best outcome for the plant, which is the question of temperature, humidity, and light. Those are the three most important things that go into a greenhouse design. We’re not talking about the soil and nutrients. That’s a different part of the equation.

The trick of a good greenhouse design is to take what nature gives you for free. Click To Tweet

From a greenhouse design point, we want to reach a good temperature, humidity, and light. We want the light to be as close to natural as possible. Using LEDs, which only use a part of the light spectrum, grow certain plants well, but they are missing certain chemicals. We’ll talk about that in a minute. For now, we’re making a greenhouse that is designed more like a solar collector. It’s oriented from the East to the West and is open toward the South.

The nice thing is the sun is shining. It is collecting sunlight. It doesn’t let it go out. The sun stays inside the greenhouse. It warms the greenhouse during the day. It can be minus 20 degrees outside. On a sunny day, if it’s a nicely insulated greenhouse that is insulated in every place where the sun doesn’t come in, that temperature inside the greenhouse can be more than 100 degrees with no problem at all.

We’ve all experienced this even with our cars. It can be 60 degrees outside, but if you leave the car windows up and it’s in the sunlight, it’s warm. You’re relying on all the greenhouse effect.

What normal people do is put on a fan and in the daytime, push all that energy out so that it becomes reasonable in the temperature, and then at night time, when you need to heat the greenhouse, they use fossil fuels to heat the greenhouse. We, amongst many other things, go and capture this energy that the sun is providing. We’re putting it under the ground, in the ground, and have the energy stored in the soil.

It comes out of the soil at nighttime to heat your greenhouse. I don’t want to vent any of the air out in the wintertime. In the wintertime, I want to keep all the heat inside. That’s a design decision. That’s where the engineering part comes in. That’s fun. How do you do that best? Do you store it in water? Do you store it in soil? Those decisions can be made depending on people’s budget and efficiency.

In this case, it sounds like you’re taking thermodynamics and the same principles that are used to create heating pumps and applying them to greenhouses.

I’m glad you’re saying that because that’s exactly what it is. In essence, it’s that heat pump, only that it is not using a compressor. At this point, it moves the energy around, but in essence, it’s the same thing.

It sounds like it would be less expensive to do because you have the soil there already, with the soil being warmer. It’s automatically going to create more heat in the space, but I can see how it will also regulate it. What do you see a dog do? When a dog goes to lie down on a hot day, they find a space in the shade. They scratch at the surface to find the cooler earth underneath. If you heat the cooler earth underneath, then that blanket is essentially going to continue radiating. It’s radiant.

Not only that but there are different ways. Being a chemical engineer, you think, “There are three ways to transmit energy. Radiation is one and conduction.” We can talk about all of this, but you’re storing it in the soil partly for radiant but also for conduction. As the air flows through this ground, it will heat the air up and therefore, it will then bring warm air back into the greenhouse.

I can already see how this whole system would work in a circular fashion to contribute to sustainable food production, reduce CO2 emissions, and put healthy food in the hands of people where they need it as opposed to far away from them. Are there any particular examples that you presently have of cities within the United States where this is already benefiting a local community and has enough scale to support 10,000 people? It’s just on the small side.

We have a few such examples. One of them is a small company started by somebody who was a former wealth manager. It’s called greenshaus. They are near Ottawa and Ontario. He has one greenhouse that he built a little while ago. His name is Rob Lyle. He learned everything about growing, from wealth management to growing lettuce. It is one bigger step than normal, but he is interested and has been making daily deliveries to supermarkets. He sells the idea of hyper-local lettuce.

He is very successful and is thinking about upgrading to a facility that has 60,000 square feet of space and will make 12,000 heads of lettuce a day. That is one where he is upgrading. I’m using that because they’re the cold places. We have a kind that grows aquaponically in Gunnison, Colorado, which is the coldest place in the lower 48 states. It’s extremely cold. Minus 40 degrees happens almost daily in the winter.

He’s also a professor at the local university and very successful in growing and selling lettuces in the local market. Those are extreme places. You don’t need to be that extreme. There are many places in the US where this works. The same technologies with the same ideas can also work not only in very cold places but also in very warm places. We don’t need to go there here. I’m saying these are all engineering problems that you can solve as long as you’re open to making decisions that are best for the local economy and not using one solution everywhere because that doesn’t work. Being flexible is the part that makes things work as a whole.

CMBB 164 | Greenhouse
Greenhouse: Being flexible is the part that makes things work as a whole.


In an earlier episode, I interviewed Paul Hawken, who’s well-known in the regenerative space. He’s the architect of Project Drawdown and wrote the book Regeneration: Ending the Climate Crisis in One Generation. I asked him a question about some of these technologies we have for growing food, namely vertical farming.

His criticism of vertical farming was, “Go ahead and tell me what foods you eat in a day.” People mentioned grains, beans, and legumes. Perhaps some animal proteins are in there, but he’s like, “It won’t work for that. You’re only going to be able to grow microgreens, maybe some tomatoes, beans, or something to that effect. Are you going to scale something like soy, corn, wheat production, millet, or these things that take vast swallows of land typically to grow?”

Some of those solutions, while they sound good like, “If you’re growing in a vertical farm, you’re able to have a smaller footprint, automate all of these things, have the plants grown without soil pushing to them the nutrients they need and the visible light that they need to grow.” I don’t think that’s necessarily going to have the same nutrient profile as something grown in soil. You can prove that. I also wonder what your retort would be to that criticism about vertical farming, which may or may not even connect to greenhouse farming.

That’s a fun topic. I’m sure I’ll step into some areas that maybe people may not be all like, but I have an opinion like anybody else. Let me start with this. I believe traditional farming will always be there. You have to farm on scales for certain crops that you cannot do in a greenhouse, nor should you, nor does that make any sense, nor is the value there to do that.

A significant part of your diet has to come from traditional farming. I can’t see this going well. One of your guests, Steven Cornwell, said, “I don’t see how that couldn’t be done in the greenhouse.” It can be done. It’s the question of value. I don’t believe that the value will be big enough. I was at a big indoor ad conference in New York. They said there’s no way to scale up greenhouses in this country to the degree that it would cover all the lettuce and earth production, which are very easy to grow in greenhouses, even if that is not possible.

We don’t need to think about corn and soy. This is a different world. The greenhouse world or it’s better called controlled environmental agriculture, has a specific area, which is very good. Those are vegetables generally that have higher value, leafy greens and strawberries. Besides, there isn’t a whole lot of value. The greenhouses can help grow these vegetables very well with minimal environmental impact, meaning much less water usage, much less energy usage, not less than it’s on the outside, but at a much much better quality. It can be grown much denser per area, which then allows shorter distances to the customers. It was clear and said, “I want everything at the customer stores within two days.” Some of the customers that I mentioned have it there on the same day.

It is incredible because I’ve even seen some footage of people taking fresh lettuce and breaking it in the field. It shows us a white texture almost like if you pick a dandelion. It’s a sap essentially, but if you do that with the same lettuce that has been sitting in the grocery store for a week, it doesn’t do that. It doesn’t taste, smell, or look the same. It doesn’t have the same nutrition. It’s essentially you have already started to break down. If we can do it on the same day, then you win.

You saw The Need To Grow movie. I’ve watched that. You can see it very clearly. They talked about the quality of the food. I had the pleasure to work with a scientist of one of the biggest tomato growers in the US in Florida. I visited him. He was very proud of the tomato that he came up with. He let me try it. It was exciting. He was happy. He is a typical nerd. I could completely bond with him. He said, “I’m making this awesome tomato.” We know that tomatoes stored below 50 degrees for the first few hours will decrease the nutrient density by about half.

Supermarkets these days know well enough that tomatoes are not put into cold storage. They all open on the floor somewhere. That is great. When they come out of a distribution center, they get shipped together with the lettuce that needs to be cold and everything else in the whole truck is cold. By the time it gets to the market, it’s already wasted. You have the best tomato in the world and you already killed it. This is where the short distance to the consumer is essential.

This is the reason. I’m budding in here because I want to share that this is the reason I go to farmers’ markets as opposed to going to the grocery store to buy my produce as much as possible. I do that on Saturdays. There’s a local one here on Saturdays, but I’m getting through this local. It tastes better. It remains fresh longer. I can keep it at room temp. It doesn’t sit there and rot in a day. The strawberries are perhaps the exception. They tend to go rather fast. We’ll take some of them and freeze them for later use. My kids like to eat them super fast, so it’s not a problem.

If I was confident that my grocery store got vegetables that were grown and sourced locally, then that story might change, but I’m not. I see the giant trucks pull up the refrigerated big haulers, the eighteen-wheelers. They’re unloading food that is wrapped in plastic. That is probably been on that truck for a week.

Rob easily competes with that and says, “They do all their stuff. Mine is separate. It stands there and it’s sold out right away. I can’t even deliver it fast enough because it is hyperlocal. People buy it.” The question that we all have to ask is, “What is it worth to us?” Rob tries to keep the price very similar to the material for the lettuce that comes from 2,500 miles away. In this case, it comes all the way from the other side of the country.

“We have to choose.” Every one of your speakers says, “It’s the customer that needs to choose, then the market will provide.” The customer is all of us. If we don’t choose it, it doesn’t happen. Any engineering solution that we can come up with makes no difference if we, as consumers, don’t care. We need to care, which is what your show is about.

The frustration point is that I can make all those decisions, but it doesn’t move the needle for the Raleys and Nob Hill down the street or the Safeway, Albertsons, Whole Foods or Sprouts Farmers Market. Even those stores like Whole Foods or Sprouts call themselves the Natural Grocery Store and more natural-leaning store.

Hyper-locality isn’t something that’s on the radar for them because they’re looking to build economies of scale and efficiencies. I can’t imagine a day when their supply chains would shift so much that Rob Lyle’s greenhouse-style work would end up on their shelves. How do we push for that? How did I push for one of these big guys to make that leap when so much of what I put on the table seems to dictate what they’ll put on the shelf?

The changes are happening. We know the supermarket in Boulder that is very happy next to my house or relatively close is called Lucky’s Market. They made a pledge that 10% of all the products are local, which in Colorado is quite difficult because when you consider that we have a growing season that only starts early in May and just ends, that is a challenge and they’re making it work. It certainly comes with the slow-money approach.

When your tash is out there, there are lots of people that help us move there and in the local Whole Foods when you walk in, you can see on each of the window panes of their glass front window pictures of local farms that they are promoting in many restaurants in town. It’s the same thing. They’d have a list of all the local farms that are there. It is not happening as quickly as we would like it, but it is happening.

I’m glad to see that. I am worried at times that these words are going to be co-opted in greenwashed like, “What does hyperlocal mean? is it going to be regulated in some ways they can’t be abused?” It’s defined as something that doesn’t require a refrigerated truck to move it, but what does that mean? How many days? You could start to split there.

You had another guest speaking about 100 miles from the restaurant. In this particular case, we look at that a little bigger than 100 miles from the supermarket, but certainly all of Colorado, and mostly the east side of Colorado. Many of the products that they sell are from town. Boulder is a food town. It’s for foodies. There are lots of people who invest. I feel very clearly that there is a shift. This shift is happening. It makes me feel happy.

Like Molly said before, “I had to provide all this during the pandemic. Now my sales are down by 70%. I feel sad about that. I continue to stay with the CSA because that’s our biggest contribution that we can make in terms of the fluid site.” The dollars that you’re spending in your own town are paying back triple. It is the number that I heard from slow-food people. You keep the dollars in your community. It makes much more sense than giving it to other places.

I don’t even talk about China and all of that, which is a completely different topic, but on the food side alone, we all have to make these choices. We need to be enticed. When people take the time and taste their food, that’s the big issue. If they taste their food truly and don’t take a bite between running and doing five different things, then you don’t value food. We need to value it and understand that there’s a health benefit or if we don’t do that, there’s a cost associated with not paying attention to your food. Not necessarily everybody knows that, but more people are starting to know that.

There's a cost associated with not paying attention to your food. Click To Tweet

I wonder if you could help settle something for me and my understanding in relation to greenhouses. My perception is that products grown in greenhouses would be less susceptible to pests and we’d have to use fewer pesticides. Since the growing conditions are more controlled, the synthetic fertilizer likelihood would be lower and the overall impact on the environment in a negative way and also on the food would therefore be less. Am I right in making that assumption or is this a pipe dream?

That depends on the greenhouse you have. In that particular case, it depends on the amount of light or the quality of light that you have. If you have greenhouses that are letting the full spectrum of the light, including new light, especially if that light is diffused, meaning bouncing everywhere, then I’m going to say this as a joke with kids, “You shine the light on the sex life of the box,” and they don’t like it. They are not happy. They don’t proliferate. It’s what happens.

When you use the wrong glazing materials that take the UV light out, all of a sudden, every bug is going to be happy and say, “This is great. Here, it’s nice, warm, and cozy all year long. It’s nice and moist. I’m having a great time. That pesky UV light is not going to be bugging me. I’m going to be happy.” It depends on the light quality that you have in your greenhouse. There are not many materials that let the full spectrum in. We use the picture that’s called ETFE, which is much more sustainable in many ways than glasses.

It can fit glasses 50 times more CO2 than ETFE does. Those are impressive numbers and they can help reduce the pests in greenhouses, but you need to be careful in a greenhouse depending on how you grow. If you are growing in aquaponics, which is a very sustainable way to do this, meaning you use fish, you feed the fish. The fish poop. It goes to the plants. The plants have the biology to match it and that is embedded into the system so that the plants get the nutrients given to them in the right way.

That is a very healthy way to grow in a water culture. It is very hard to control pests because those traditional pest control methods would kill your fish. You know something is grown in an aquaponic system. You can do that. There are not many places where this is done on a large scale, but this is happening more and more all over the world.

Because of food safety issues, people say, “You’re growing fish and vegetables next to each other. There are all possibilities for contamination. You need to be careful.” If this is happening now, hydroponics, which uses nutrients you’re getting from the earth directly in the form that the plant can eat it, is not organic, but that’s what you talked about earlier. Now I want to see what the nutrient difference is between something that’s called hydroponically grown, grown in aquaponics, or in soil. You can do all of it. In commercial agriculture in greenhouses, soil is very solidly used.

I hadn’t thought about UV light impacting little critters because it all seems the same. It comes with visible light, but I know there are species even of algae, and I work in the algae space, where you grow algae. They get burned by the UV lights the way our skin does. Part of how they are handled is that they’re constantly moving through the water. Some are getting exposed and then it isn’t. It’s constantly cycling. That happens with the temperature convection of in the water itself naturally, whether it be at sea or in a pond.

Where we’re growing our algae in Iceland using only green energy, we show it the light bands that it needs, which is a blend of red and blue light. It’s optimal for it. It does great. To the point of those growers who might be growing, and the winter months when there isn’t a lot of light, and they’re using these lights to grow food as opposed to the sun with UV light, do you tend to recommend that they also have UV lamps included in these types of growing enclosures so that they limit that?

It is tricky to do that because the UV lamps are also somewhat directional. Meaning they’re rather strong in certain areas and not so strong in others. The nice thing about doing this in a natural way is that UV is not in a natural amount. One thing people forget, and here I’m putting on my chemical engineering hat, I look at plants as a chemical factory.

I know that the sound is not very enticing to people. It’s like, “What is this guy talking? It’s not sexy.” We looked at photosynthesis which is to say, “I take your CO2 and water, and put light in it. I make sugar and oxygen.” That’s a chemical reaction. In the world of plants, we make much more than the sugars. We make, amongst others, I can pick one, terpenes. That’s what smells. Plants make terpenes and every plant does.

They are used for many reasons. For the plant, it can be pest or critter control. There are 30,000 of them. This is chemical. We measure that on a plant-to-plant basis in the cannabis world because it’s a high-value crop. It’s very easy for us to measure what environmental conditions and what light we need to make the terpenes we want. We can do the same thing with plants, tomatoes, and everything else.

These terpenes are what you would find in essential oils. Anybody likes essential oil, it smells good. Those are terpenes. They’re made by plants. Plants make chemicals. That’s normal. We need to make plants. We need to give plants the ability to produce the chemicals that are most beneficial under the best circumstances. That is something that agriculture cannot provide because, in agriculture, you have to take whatever the conditions are outside. In a controlled environment, you can change that or you can change the light as well.

CMBB 164 | Greenhouse
Greenhouse: We need to give plants the ability to produce the chemicals that are most beneficial under the best circumstances. That is something that agriculture cannot provide.


What we have found is that the UV light significantly affects these terpenes. Having more UV light increases the terpenes, the flavor profile, the taste, and the smell of whatever you’re eating as well as other chemicals. I used terpenes in this case because it was very easy. In tomatoes, you can talk about lycopene. It doesn’t matter.

We are at the beginning of understanding these differences. It is super exciting in our world to make better food by getting into these conditions. We have learned a lot through this cannabis world because there, the value was immediate. It is now trickling down. It’s a trickle-down effect that I like that it goes into food production. It is going to the lettuce, tomatoes, strawberries, and everywhere. This is a super exciting time for work in controlled environmental agriculture. It’s amazing.

This is a super exciting time for work in controlled environmental agriculture. Click To Tweet

What you’re revealing to me is that growing, when you take it indoors, whether it be aquaponics, a vertical farm, a standard greenhouse, or what we’re doing with Örlö Nutrition, technologies, and growing algae in these photobioreactors indoors, a lot of it is engineering problems. You’re talking about input versus output. No wonder this gets your creative juices flowing because essentially, you have to feed nitrates, phosphorus, and things like that in order for the plant to grow and in different balances for different plants, but to understand that natural ultraviolet light impacts the flavor profile of tomato, leaf of spinach, and whatever the plant is.

I immediately went to arugula as an example. People who consume arugula may know that if you pick it early in the growing season when the leaves are newer, it’s not as spicy. If you let it grow super tall and bush out, it can be spicy. It’s hard to eat. That’s the terpenes because I’m thinking about the chemical compounds in these things too. Some of them can trend bitter and a little bit more spicy. Trying to harvest the fruit and the food at its peak of nutrition is hard to do in math-scale farming because even within a single plot, the conditions from one edge of the property to another can vary so much.

I’m thinking about something like this greenhouse growing and saying, “This is a smaller scale but still scalable. You can grow foods like lettuce and tomato, probably broccoli, and some of the other crucifers.” They don’t take up an incredible amount of space to grow, but there seems to be much science going into this that we’re in the early phase and we’re learning more.

I don’t know if you recognize it. Do you know where the idea of organic farming came from or how old that is? Generally, when you look this up, there was a guy called Albert Howard. He was British. He worked in India in 1909. He described Indian farming practices and was generally looked at as somewhat of a first stage of the organic movement, but the person who pushed this was Rudolf Steiner, who was the Founder of the Waldorf school system.

He gave a presentation in 1924 with 111 participants in to talk about the first bio-dynamic concept. It was shortly before his death and he changed farming with that forever. He talked about soil biota already then. From there, it happened that one of his students was an uncle of mine, Dr. Hans Müller, who I met very well in Switzerland. He started the first bio label called BIoland in Switzerland. That step happened in the ‘50s. We have been learning about food and the quality of food for hundreds of years in written documents. Not only in generations since humans started farming but scientifically since hundreds of years.

CMBB 164 | Greenhouse
Greenhouse: We have been learning about food quality for hundreds of years in written documents. Not only in generations since humans started farming, but scientifically since hundreds of years.


I start on greenhouses. I thought, “How long can this take? It cannot be that difficult. Let’s say, 1 or 2 years, and I know everything that needs to be known about greenhouses.” The reality is once you start doing this, some of my list of research projects will change the world in terms of food quality and as well as energy efficiency using solar thermal to heat greenhouses. Those questions are big and relevant to us.

If we had enough funding to do it all, I would, but this is more than 30 projects that we know will change. I can’t get rid of them as quickly as I add new ones to it as a company. What we need to think about is it is not the individuals’ contribution. It’s not Rudolf Steiner, my uncle, or you and I. You do an awesome job by spreading these ideas. This is where I want to go as an organization for Ceres. I must make sure that we train the young people to feel that they are confident, they have power, and they can change the world instead of sitting back and saying, “This is too big. I can’t do it.”

It’s like, “You can and you must. You have an iPhone 14 or more. You are privileged.” If you are privileged, you have a responsibility to society to make this better. This is what we do as an organization. We still run organizations mostly in older structures. I learned at the core that there is a different way to look at this. There’s now something we’re running. It’s called holacracy. It is a completely different way of organizing a company that encourages people not in this traditional hierarchical system but in a way, you don’t have static job descriptions. They change.

We have wage transparency, but we also now instituted an unlimited vacation policy. There are ways to not just look at food, but look at our society and everything in it to make this. I didn’t want it to be just to talk about food only and greenhouses. All of that is important. It is much more important that young people nowadays get the knowledge that we have to share and that we learn from them so that they can make the world better because that multiplying effect is the only way that we can dig ourselves out of our problems. If we hang on to the knowledge, it’s all worth nothing.

CMBB 164 | Greenhouse
Greenhouse: If we hang on to the knowledge, it’s all worth nothing.


I 100% agree with everything you shared. I feel like it connects nicely to this concept of hyper locality because if we’re taking care of our own companies, the way we organize, the way we care for employees or coworkers, the grace we give them if they need to, as Kristel De Groot who I interviewed on another show I host called Nutrition Without Compromise. She instituted what she calls Moon Days for women menstruating.

When they had a Moon Day, they could take a day off because they didn’t feel good. It’s a sick day in another way. Everyone has this experience. At first, the board and other people there are sitting there saying, “You’re giving more vacation time up to twelve or more to women.” It’s like, “No. We’re taking care of our women and ultimately, we think that this will improve their productivity because there is going to be gratitude. I don’t think it will be abused on and on.”

If we’re looking at this as a holacracy and I love that word, then we take that approach with our food and the people who help us farm and procure it. We take that approach with how we even shop, then we are going to make a bigger difference on a daily. I appreciate those closing remarks. I do want to offer you the opportunity to leave us with one more thought if you care to or if there is a question that you wish I had asked, you could ask and answer it.

I do think that what we are trying to reach is a holistic approach, not only to the greenhouses or the food that we grow and the organizations that we try to create, but how we are trying to bring people together in the way that exactly you are doing with the show. This is the part that we need to inspire others to help in this process. It is difficult at times, but it is the greatest joy that you could ever have. You are helping us get there. I am thankful that you’re doing this. This means the world to me. I’m happy that you’re pushing us all to be better.

Thank you so much. It has been an honor and privilege to host this conversation. I learned a thing or two as well. I wish I had enough space to incorporate one of your beautiful greenhouses on my property. I’m battling the squirrels and the little plot of land. I try to farm squirrels and other rodents who seem to want to eat the ripest part of every tomato I grow.

They know what’s good.

They leave it growing in the vine and eat the ripest part. Thank you so much.

Thank you so much.

What a pleasure to learn with an engineer and someone who also stays focused on helping to reach a natural balance. I wanted to share a few key takeaways that I have come through with. One is that design decisions matter. Focusing on hyper locality is one of the only ways forward and balancing the right amount of technology with natural solutions can bring us toward a more sustainable future. It can improve the success of companies and growers that are seeking to support hyper locality as well.

When we go through that and support local, regional food sources and businesses down the line, the money stays in our community and can do three times the benefit. It has three times the power. I hope that we helped you care a little bit more about where your food is coming from. That will necessarily impact the future of food, your health, and your community.

You’ll receive a special gift if you join our newsletter. It’s simply a five-step guide to help organize your efforts, inspire your activism, and live a greener life. This was the birthchild of my years in graduate school for my MBA and a gift for all of you. I hope you’ll write us a comment. Give us a thumbs up and a five-star rating. Be sure to subscribe and set that bell to notify you when we release new episodes.

Not only does all of this help us reach more people, but it will also ensure that you’re alerted when we have a next great guest come on. If you’ll do me the favor of writing us a review on Apple Podcasts, that helps us even more. Thank you, now and always, for being a part of this show and community because together, we can do so much more. We can care more, be better, and grow more nutritious food with a smaller carbon footprint and a greater connection to our communities.


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  • Marc Plinke

    Marc is an inventor-innovator who started his career as a chemical and process engineer at W.L. Gore (Gore Tex). When landed in Boulder, CO, he retrofitted his family's 1960's ranch house into a "beyond-net-zero-energy home." That experience led him into his second career in green building design. He has spent the past decade applying his engineering mindset and expertise to building better greenhouses. After helping build a state-of-the-art commercial greenhouse funded by the Colorado Department of Agriculture, Marc started Ceres Greenhouse Solutions with the intention of enabling people to grow their own food sustainably and year-round. Marc’s passion is his family and his belief in leaving the world a better place for his children.

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