‘bio-productive gardens,’ with tim johnson of native plant trust

IN A RECENT phone call, Tim Johnson used the phrase “bio-productive gardens,” and it stopped me.

“What does he mean by that?” I thought.

And then he explained: “There are ways to manage our landscapes,” he said, “so that everything that flows through them, from rainwater to birds, leaves healthier than when it arrived.”

“Tell me more,” I replied. And so that’s my topic today with Tim, the new leader of the longtime conservation organization called Native Plant Trust. We talked about the thought process he’s applying to making his own home garden, and about bigger projects at work.

In January Tim became chief executive officer at the non-profit, which was founded almost 125 years ago as the nation’s first plant conservation organization and the only one solely focused on New England’s native plants. Tim, with his extensive background in environmental horticulture and biological science, recently led the Smith College Botanic Garden.

Read along as you listen to the March 18, 2024 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify (and browse my archive of podcasts here).

(Photo of Cercis canadensis, or Eastern redbud, above, from Native Plant Trust; portrait of Tim Johnson, below, by Sam Masinter.)

‘bio-productive gardens,’ with tim johnson

Margaret Roach: So new job. Getting acclimated? You’ve been I guess since what, late January, maybe, that you’ve been in the position?

Tim Johnson: New job, Week 7. And I do keep saying though, I feel a little bit more like I changed offices than organizations. Native Plant Trust was a close partner when I was at the Botanic Garden, and it’s a team that I’ve really looked up to and been fortunate to have in my professional network for many years.

Margaret: Yeah. Well, and as I said in the introduction, Native Plant Trust, which was founded as New England Wild Flower Society almost 125 years ago, I think, is a conservation organization focused on New England plants. But for people who might not know, give us the … How do you describe it when you tell people what the sort of mission, what you’re doing there, what the emphasis is all these years later at this place that’s so historic?

Tim: Yeah, that’s a great question. Native Plant Trust is an organization that is so much more dynamic than I understood from the outside. The most important programs are conservation, horticulture, and education, and we really work at a regional scale to fulfill all three of those departmental visions and missions.

So our conservation program does a great deal of work coordinating efforts throughout a region, working with state, local, non-profit conservation professionals, as well as community members. We do a lot of work with the general public on rare-species monitoring.

Our horticulture program works at Garden in the Woods, but they’re also really influencing the way we garden and think about landscapes throughout the region. And then our education program does a mix of in-person and virtual, as well as multi-educational programs that are happening at different sites throughout New England.

Margaret: So you said that the horticulture, a lot of it’s focused at Garden in the Woods, your sort of headquarters, is that-

Tim: That’s right. Garden in the Woods is one of our properties. We also have Nasami Farm in Western Massachusetts, as well as sanctuaries throughout New England.

Margaret: Right. And it’s the cusp of spring. And for gardeners who are within reach of New England, or are going to be visiting the area or whatever, I mean, definitely a destination, both Nasami Farm and Garden in the Woods. And if you like to shop for native plants [laughter], it’s even a double destination. Not just beautiful places and places to see these glorious things, but lots of wonderful … You’re propagating native plants and selling native plants, and so there’s a lot to engage with is what I’m trying to say. Must visit. Put it on the list of must visit, right? [Plants for sale at Nasami Farm, above; photo by Jane Roy Brown for Native Plant Trust.]

Tim: Yes. And in particular, we really strive for the plants that we’re selling to come from locally adapted seed sources. And so our take even on seed sales is a little bit different because rather than cloning plants, rather than working from cuttings, we’re trying to be working from genetically-diverse populations.

Margaret: So, bio-productive gardens: You really threw me [laughter], as I said in the introduction, I just didn’t know the phrase. And so tell us what that means to you and why you sort of threw that out to me as something you wanted to have on my radar.

Tim: I have to share the credit for the idea with a colleague of mine, Dano Weisbord, who I worked with at Smith, and it came up in the landscape master-planning process that we co-chaired at Smith. And when we were trying to figure out what is the common denominator for managing our landscape, and we had all these ideas about reducing fertilizer, reducing petroleum inputs, direct and indirect, trying to really create a healthy environment, we landed on this idea of bio-productive landscapes. And the idea that, if we think about our built landscape as an extension of nature, we really should be focusing on the ecological processes that are facilitated within these landscapes that are in our urban and suburban environments.

Margaret: And so, one of the things you said to me when we talked the other day is that it’s the idea that everything that flows through them leaves healthier, whether it’s water or a bird, as I said in the introduction. So tell us a little bit about examples of that, about what you have, sort of, what’s in front of mind if you are going to be a bio-productive landscaper or a gardener? What are the elements and the organisms that you have in mind? Is it from microbes up to mammals [laughter]? What is-

Tim: Yeah, absolutely.

Margaret: Is it both living organisms and resources, so to speak, like rainwater?

Tim: Yeah, it is a holistic look about the abiotic and the biotic. And so an interesting thing, at least in my head as a gardener, happened when I started to think about, “Well, can I garden in a way that’s bio-productive?” is I started to question the use of some traditional practices. So for example, would I be willing to use insecticides for problems? Sometimes we face really, really difficult problems as gardeners. And I became less and less willing to do that because I didn’t like what it was going to do for the micro-communities; I didn’t like what it was going to do for water. I became concerned about incidental damage, for example, to honeybees and solitary bees visiting my garden. And so I stopped doing that.

The other thing that I’ve really come to embrace with this methodology, with this … maybe it’s more of a philosophy, is to really work with what I have in my space. I am on a very, very sandy lot, it does not want to be a lawn. And if I try to keep it as a lawn, I’m going to have to put in a lot of water. I’m going to have to put in a lot of fertilizer and it’s going to be a lot of lawn mowing as well to manage it. But if I start to think about what would like to be here in this very sandy soil, I can start to work with the environment. And if I want to actually change it over the longer term, I can bring in nitrogen-fixing plants, I can start to slowly enrich the quality of the soil. And there again, it’s enhancing rather than consuming the landscape that I’m gardening within.

Margaret: Right. So really then every step of the process—the plant palette, any other inputs, whether it’s, like you were just saying, an insecticide or something like that, the use of any material that you’d be sort of bringing in or any natural resource—you’re really sort of figuring how to do it in the most beneficial and conservation-minded way. Is that-

Tim: That’s right. I think one of the principles I’ve really come to embrace comes from restoration ecology, where if we kind of look at what is dysfunctional in a habitat, we might be able to actually address that and then have a much more autogenic garden. So again, if I have very, very sandy soil and I’m putting in plants that really do not want … If I were to try to plant an apple orchard with my soil [laughter], it’s going to be quite challenging. I’m going to have to constantly fertilize it. Not to mention we have problems with fire blight and things like that.

Amelanchier grows really well here, actually; it’s very happy. And so that’s also an edible fruit. And so thinking much more dynamically. And even thinking about the tools that we’re using. And so at the garden, moving to electric chainsaws, making sure that when we’re putting chain oil onto the saw, we can actually use cooking oil. We don’t have to use petroleum-based oils on that. And embracing kind of this much more of a cradle-to-grave approach of thinking about how we’re doing good with the garden.

For me, I think about people moving through my landscape and wanting them to feel perfectly comfortable and know that they can eat food afterwards, or they don’t have to worry about their kids walking on the lawn or touching the plants, because they can trust that they’ll be healthier when they step through it as well. [Above: Amelanchier bartramiana; below, the blooms of A. canadensis. Both by Liza Green for Native Plant Trust.]

Margaret: Right. Now, you have a sandy soil you said, and so the shadbush you were just talking about, or what do they all call it also, serviceberry or juneberry?

Tim: Yup, serviceberry. Yup.

Margaret: Has so many different names, I think, right [laughter]?

Tim: Right.

Margaret: So that would work for you better than some of the larger fruits. And that’s a native plant, than an apple tree, an apple orchard or something like that. And so you’re doing research on plants that are willing to grow, that are adapted to a sandy soil and so forth. And so that’s one part of it.

I sort of think, and I’ve had a couple of conversations recently with experts in whatever we want to call ecological landscaping, or there’s so many different people use different language to describe it, and I call it sort of “habitat-style gardening.” Are you visualizing for this yard of yours? Are you visualizing a habitat that you’re … Do you know what I mean? Are you mimicking anything in nature in your sort of master plan or is it more you’re looking for individual plants that will work? What’s the sort of bigger picture, or?

Tim: Yeah, that’s a great question. For me, my backyard is a very sandy area. And so when I look at my landscape, increasingly I’m trying to think about how I can create an aesthetic and functional facsimile of this native habitat. I kind of have this idea that eventually my house gets plunked into this sandy prairie, sandy grassland, that even those spaces where we traditionally think about hardscaping, that it would be a softer version of hardscaping. And so if I wanted a patio, it should still be done in a way where water can infiltrate, and maybe even we’re thinking about water catchment, for example, to be reused in the environment.

I’m thinking about creating shade with trees that can really handle this sandy soil. I’m also thinking really long-term. So, again, it’s very sandy soil now, but I’m planting a number of nitrogen-fixing plants so that over the long run I’ll actually increase the fertility of that soil and I can sort of change and adapt and play with this landscape over a longer period of time. But ultimately, I do want it to fold into the surrounding environment, and also have room for people. We do need paths, we do need meeting spots. I want a fire pit. I want some of these social opportunities as well in … [Above, little bluestem, Schizachyrium scoparium, by Dan Jaffe Wilder for Native Plant Trust.]

Margaret: Right. You mentioned water and rain and a catchment area, so like an underground kind of thing, or what are you thinking about? Because one of the sort of new normal, or should we call it the new abnormal things, for those of us in the Northeast, from my observation point—I don’t know if it’s throughout the region—but it is that rain comes in dramatic events now, and sometimes it doesn’t come at all, but then it comes in inches at a time a lot of times. And with wind a lot of times, too. Obviously, it’s harder for … A soft, gentle rain [laughter] drains into the soil more easily than 3 inches in a couple of hours. And so is that part of what you’re thinking about mitigating? Now you have a fast-draining soil, a sandy soil, but are you making this … is it an underground basin, or you’re thinking of a rain garden, or what are you thinking about for that?

Tim: For me, it’s a combination. And here, Margaret, you’re really letting me dream about the future garden. I always have those big plans. One of the things I have in my backyard is this little swale; I think it’s a remnant of the construction of the subdivision that I’m in. And there I imagine that being an ephemeral stream at some point. So can I rip-rap it and sort of slowly allow water to infiltrate into that area, and give me the opportunity then in those areas where I do have drainage issues to push water into that water catchment to become a rain garden?

I’m also thinking about the future. And yes, how do I take advantage of this house that I live in, that during rain events, is a water catchment system? Because I would much rather be storing water that’s coming from rain, and using that in the garden, than using our potable water, which is what we’re reliant on at the tap, right? This is water that is really precious and it’s treated, and it takes a lot of energy in order to create safe drinking water. And it’s a little bit of an overuse in our landscapes. And so for us to be able to store it a little bit and then use it over a longer period of time is another way that we’re actually improving the quality of our water system.

Margaret: Right. I love that you said you could rip-rap that. You could rip-rap it, about that swale [laughter]. I haven’t heard that expression, rip-rap kind of … Well, I think of it as using stones to sort of line either a hillside. Or rip-rap, I don’t know, I don’t even know what the formal definition of it is, but-

Tim: You’ve got it. I am imagining-

Margaret: … lining it with stone.

Tim: Yes. I’m imagining a fake stream that might flow a little bit in the spring. It may be a water catchment from time to time, and offers a lot of hiding spots, offers a lot of habitat for my local insects and amphibians.

And we are really lucky, we have a backyard that’s already regularly visited by bobcats and by foxes, and we really cherish that as a family. And so I want those animals that are in our backyard to be able to benefit as well. So I could imagine them drinking from this little ephemeral space, as the water slowly percolates in. And migratory birds being able to use it. Or lining it even with early, or early and late-fruiting plants, so that it becomes a resting spot for them.

Margaret: I like the idea. And, again, I’m trying to make myself be more conscious about this, during the rain events, to go out and look. You don’t normally want to go out while it’s pouring and in the aftermath especially, but to really … I think one of the things, those of us who are in areas, and there are a lot of regions of the country that are experiencing these downpours and so forth, and the effects of it, one if the things is to observe.

Like you’ve observed that there’s this swale and it might have been the aftermath of construction, as you said, but maybe you could utilize it and enhance it. And I feel like that’s one of our big jobs as the climate shifts and as we have these events, these rain events, is to go and look and see what can we do to move the water in a more productive way.

And I hadn’t thought about storing some of it, as much as moving it away from areas where it causes harm or erosion or whatever damage, but I think this is … I feel like I need to do more forensic investigation, you know what I mean, of where’s the water going nowadays because it’s coming in these bigger events. So how’s it moving in my property? What can I do, if anything? And I love the idea of rip-rapping some of the … If I were to make a swale or rain garden, I love that, because I think it could also be beautiful and inviting, as you say, to various creatures.

Tim: And, Margaret, I wonder how you feel about this, and I wonder about your trajectory as a gardener as well. One of the things I’ve found is that my interest as a gardener really started with curiosity about plants and then eventually, can I keep them alive? But the more I garden, the more I become more interested in the very mundane aspects of it. I’m enamored by, in my vegetable garden, the weeding process. I really enjoy that. I think a lot more about soil than I did five or six years ago. I’m now thinking about soil on a two- and three-year trajectory, rather than just as the thing I put the plants into. And I think there’s a component of this, too, with the habitat, is starting to think in time and longer time periods within the garden. And I’m curious if that’s been your experience as a gardener too, that you’re becoming a little more focused on maybe the less-glamorous aspects of gardens.

Margaret: I definitely am. And part of it, unfortunately, is because, again, of some of these changes in what was a familiar … The soil was familiar to me, the patterns of weather were more familiar to me. And I’ve been kind of reawakened, in a rude way [laughter], by these shifts.

And for me, as far as the soil and what’s worrying me about that, and I don’t know if you have them there. Where I am and throughout a lot of … I think 38 states are affected now, parts of 38 states, I have the invasive jumping worms [above]. And they degrade the soil so substantially. So having a new version of my old soil is … It’s like having to re-acclimate. So for me, that’s a particular hot button right now, and I’m trying to feel my way through it.

Tim: Yeah. This may be one of the moments where there is a stronger way for folks who may not already be soil obsessed, where they come to understand how critical it is. I’m absolutely with you. I’m not quite sure what the solutions are, yet, for jumping worms, but the idea that our soils might be burning through their nutrients faster … We thought of these as the repositories, the things … I think about the soil as the thing that I’m investing in so that it can grow the plants that I want to grow. And as it changes, I almost feel like I’ve got a family member who’s in need of help to try and slow a disease. And I’m not quite sure what to do with that one yet.

Margaret: No, but I think just like what I was talking about with the rain, just covering our eyes, ears [laughter], and just like hear no evil, see no evil isn’t going to help. So watching and trying to draw inferences, I think that … and obviously reading the research as it’s published and so forth, I think that’s going to be important. Feeling our way through.

And I think this attitude, this mindset that you’re talking about, about being a bio-productive gardener, so in other words, thinking about every step, and thinking about every input or every action ahead of time. I think that kind of consciousness, I mean hopefully that’s going to help us to figure out these obstacles, of how to deal with some of these obstacles the best way possible, hopefully.

So anything else about bio-productive gardening? Anything else that comes to mind? I mean, I love the idea of … I hadn’t even thought of getting a non-petroleum oil for tools. I don’t use a chainsaw myself. But for tools and stuff, using a cooking oil or a vegetable oil, kind of thing. So even that extra quart that you buy can be not petroleum-based.

Tim: Yeah. I think too, for me, embracing electric also means a much more pleasant environment when I’m using those tools. It’s-

Margaret: Boy, it’s so much less loud, isn’t it?

Tim: So much less noise. You’re not generating exhaust fumes that you’re breathing in. When you start them up and shut them off, it’s much more instantaneous. You don’t have that constant revving engine. It does actually just make even the management of our landscapes a lot more enjoyable.

I think the big thing, too, is I always want to make sure that gardeners and people who are exploring new things with the best intentions, that they feel empowered to step into that space and that the goal is not to be perfect, it’s to just be better. And so there’s things that I’m doing and not doing now that five years ago felt O.K. to me. And I just have a different perspective, and it will continue to shift. And that’s actually the huge joy of gardening, is that we get to change with it, and it gets to change us.

Margaret: Anything else you want to tell us about in terms of that’s going on that you’re excited about at Native Plant Trust? I mean, I’m excited about your native seed project, and you alluded to that before. But that’s one that I’m very interested in seeing how that goes. [Above, sowing seeds at Nasami Farm; photo by Jane Roy Brown for Native Plant Trust.]

Tim: Yeah. There’s a lot to be excited about. Native Plant Trust, before I joined the organization, kind of sent me on this journey of thinking differently. I remember visiting Garden in the Woods six years ago or so, and seeing their lawn-alternative and thinking, “That is never going to catch on.” [Laughter.] And now here I am trying to figure out how to make it work in my own garden. And it was because Plant Trust was so far ahead of the curve.

I think that part of this bio-productive landscape means that the plants in our gardens should be an extension of the genetics in our communities. And so the Northeast Seed Network is an effort to establish those reliable seed supplies of locally-adapted seed for commonly grown plants. And to do it in a way that doesn’t mean we’re constantly going back to nature and taking seeds, because we don’t want to actually disrupt those natural processes either. It’s a big project. I think Nasami is a pilot actually of how this can be done. And I would love to see a Nasami in every state and every ecoregion throughout New England, but we’ll have to wait and see if we can make that happen.

Margaret: Well, Tim Johnson, from Native Plant Trust, congratulations again on the new position. And very lot of exciting stuff under way and more to come, I bet. So I hope we’ll be in touch throughout the season ahead, and thanks for making time today to talk.

Tim: I really appreciate it. Thank you, Margaret.

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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 15th year in March 2024. 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 March 18, 2024 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify (and browse my archive of podcasts here).