Roger: 0:02

Talking Trees with Lillian Jadd. Welcome to Talking Trees. Today we review the CU Structural Soil Guide from Cornell University, which outlines the use of this patented soil in urban settings. The guide details its composition, installation, maintenance and case studies, highlighting its role in supporting healthy tree and turf growth under paved surfaces and its benefits for stormwater management.

Jad: 0:32

All right, let's talk trees. I know you're dealing with the unique challenges of keeping trees healthy in urban environments.

Lilly: 0:39

For sure.

Jad: 0:40

And today we're going to explore a tool that's becoming increasingly essential in our work CU structural soil Right, or CU soil as it's commonly known. Yep, it's likely popping up more on your projects, definitely, so let's break down what makes it so special, okay.

Lilly: 0:56

It's definitely a game changer, and what's impressive is that it's not just some trendy landscaping gimmick. Cu soil comes from Cornell's Urban Horticulture Institute.

Jad: 1:06

Okay.

Lilly: 1:07

A group that's deeply invested in understanding the science behind urban tree care.

Jad: 1:12

Yeah.

Lilly: 1:13

They've developed this technology specifically to address the stresses our trees face in these challenging settings.

Jad: 1:19

And when we talk about urban tree stresses.

Lilly: 1:22

Yeah.

Jad: 1:22

We can't ignore the elephant in the room.

Lilly: 1:24

Oh.

Jad: 1:25

Soil compassion. We can choose the toughest tree species, but if their roots are trapped in compacted soil, it's like trying to breathe in a tiny airless box Exactly. It's often the silent killer that drastically reduces a tree's lifespan. In the city, it's a sobering thought, but urban trees often live only 20 to 30 years. Wow, a fraction of what they could achieve in a natural environment.

Lilly: 1:49

That's heartbreaking.

Jad: 1:50

It is.

Lilly: 1:50

Especially when you consider the time and resources we invest in planting and nurturing these trees, and it all comes down to that fundamental need for adequate soil volume. Yes, that rule of thumb two cubic feet of soil per square foot of canopy really hits home when you picture a mature tree crammed into a tiny tree pit.

Jad: 2:10

It highlights the problem perfectly.

Lilly: 2:12

Right.

Jad: 2:12

Think about it A tree with a 20-foot canopy ideally needs around 600 cubic feet of soil. Wow, those standard tree pits are simply not giving trees what they need to thrive.

Lilly: 2:24

Which brings us to CU soil. Okay, so walk us through this. What exactly are we dealing with here?

Jad: 2:29

Picture a carefully engineered system designed to provide both structural support and a healthy root environment. Okay, there are two key components. First, you have a load-bearing lattice made of angular crushed stone.

Lilly: 2:41

Okay, angular crushed stone.

Jad: 2:42

Okay, the specific size range of the stone 34 inch to 112 inches and the angular shape are crucial for creating interlocking voids that provide that structural integrity.

Lilly: 2:52

So it's not just a random pile of gravel.

Jad: 2:54

No, it's very specific. Okay, and here's a detail that often gets overlooked no fine materials allowed. This ensures the structure stays open and doesn't get clogged, which is vital for root growth.

Lilly: 3:06

But where does the soil part come in?

Jad: 3:08

That's where the second part gets exciting. Okay, those voids within the stern lattice are filled with uncompacted high clay soil at least 20% clay content, to be exact.

Lilly: 3:20

Hold on. A lot of arborists might hear high clay content and think that's a recipe for even more compaction Right? Help us understand why that's not the case with CU soil.

Jad: 3:30

You're right, that's a common concern.

Lilly: 3:31

Yeah.

Jad: 3:32

But here's the key difference Within the CU soil structure, the clay remains uncompacted.

Lilly: 3:38

This is critical because it provides excellent water and nutrient retention.

Jad: 3:42

Gotcha.

Lilly: 3:43

That clay content also contributes to good concation exchange capacity which, as you know, is essential for making nutrients available to the tree roots.

Jad: 3:53

So it's like this carefully orchestrated balance Right, the stone provides the structure, yep, the clay provides the life support.

Lilly: 3:59

Exactly.

Jad: 4:00

And together they create this ideal underground habitat for trees. Yes, but what about that Gelscape Taka fire I keep hearing about? Yeah, is that just a fancy glue.

Lilly: 4:10

It's actually pretty clever.

Jad: 4:12

Okay.

Lilly: 4:12

The Taka fire is a temporary binder that prevents the stone and soil from separating during transport and installation. It ensures that when the CU soil arrives on site, it's ready to go and performs as intended. Got it and don't worry, it's completely non-toxic and breaks down naturally, so it won't harm the tree roots.

Jad: 4:29

So we've got this blend of stone soil and a touch of temporary magic, but how does it actually work in practice and why is it so much better than conventional soil, especially in the urban jungle?

Lilly: 4:39

Imagine this You're compacting the CU soil during installation, which counterintuitively actually strengthens the load-bearing base. The compaction force is transferred through the angular stone, creating a really stable foundation for pavements or whatever you're building on top.

Roger: 4:55

Okay.

Lilly: 4:56

But here's the brilliant part While it's becoming super strong under compaction, it's simultaneously maintaining those crucial open spaces between the stones.

Roger: 5:05

Wow.

Lilly: 5:05

So you get the structural support you need for urban infrastructure while preserving that essential root space.

Jad: 5:11

That's what I'm talking about.

Lilly: 5:12

Yeah.

Jad: 5:12

Innovation that works on multiple levels, for sure, but we're visual people.

Lilly: 5:16

Right.

Jad: 5:16

Are there actual examples of how root growth differs in CU soil compared to, say, a typical compacted clay pit?

Lilly: 5:24

Absolutely, absolutely.

Jad: 5:25

Okay.

Lilly: 5:25

There are some striking images that show this difference. Yeah, In CU soil you see these robust, expansive root systems.

Jad: 5:31

Okay.

Lilly: 5:31

While in compacted soil, roots are often stunted and circling.

Jad: 5:35

Wow, desperately searching for space.

Lilly: 5:37

It makes you wonder how any trees survive in those conditions at all.

Jad: 5:40

I know.

Lilly: 5:41

So it seems like the ratio of stone to soil is critical. Yeah, too much soil and you lose that structural support Right. Too little soil and the priest suffers.

Jad: 5:51

Exactly. Yeah, it's not just about throwing some gravel and dirt together, right? It's a carefully engineered system and that's why it's patented and licensed. Okay, you want to ensure you're getting the real deal from licensed producers, because that quality control is essential for consistent performance.

Lilly: 6:07

That's a great point.

Jad: 6:08

Yeah.

Lilly: 6:08

Especially for us arborists who are specifying these materials For sure. Now let's get down to the nitty gritty.

Jad: 6:14

Okay.

Lilly: 6:14

I know a lot of arborists have questions about how to actually work with CU soil in the field, uh-huh. What are some of the key things we need to consider?

Jad: 6:23

Let's start with volume All right. Remember that two to one rule we mentioned earlier. Yeah, two cubic feet of CU soil for every square foot of canopy Right.

Lilly: 6:31

To put that into perspective for a 20 foot canopy tree.

Jad: 6:35

Okay.

Lilly: 6:35

That's about 600 cubic feet of CU soil.

Jad: 6:38

Wow, that really emphasizes why those tiny tree pits are doing our trees a disservice.

Lilly: 6:43

Yeah, they're really rough.

Jad: 6:44

What about depth? Yeah, how deep do?

Lilly: 6:47

we need to go with this. A minimum of 24 inches is generally recommended.

Jad: 6:50

Okay.

Lilly: 6:50

But ideally you're aiming for 36 inches. This is where the long-term benefits really shine.

Roger: 6:56

Yeah.

Lilly: 6:56

Deeper installations allow for those deep root systems that are less likely to cause heaving issues with sidewalks and pavement.

Jad: 7:04

Yeah, I've seen that.

Lilly: 7:04

It's a win-win for the tree and the surrounding infrastructure.

Jad: 7:07

Speaking of long-term, how does CU soil hold up over time? Is there a concern about breakdown or settling that could impact its performance?

Lilly: 7:18

Oh, that's a question I hear a lot and the research actually puts those concerns to rest. There was an excavation of a seven-year-old CU soil installation and they found virtually no soil migration, because the voids between the stones are mostly filled with soil.

Jad: 7:34

There's very little space for shifting and settling.

Lilly: 7:37

So it's a system that's designed for the long haul.

Jad: 7:39

Exactly.

Lilly: 7:39

That's a strong selling point, both for us and for our clients, who want to see a return on their investment.

Jad: 7:45

For sure.

Lilly: 7:46

Now let's talk about a question that often comes up on job sites.

Jad: 7:48

Okay.

Lilly: 7:49

Can we mix regular soil with CU soil, especially when dealing with existing soil conditions?

Jad: 7:57

That's where it gets a bit tricky.

Lilly: 7:58

Okay.

Jad: 7:59

Generally, mixing regular soil with CU soil is not recommended.

Lilly: 8:03

Gotcha.

Jad: 8:04

Because it can alter those carefully calibrated ratios.

Lilly: 8:06

Yeah.

Jad: 8:07

And potentially compromise the structural integrity.

Lilly: 8:09

But let's be real.

Jad: 8:10

Right.

Lilly: 8:11

In the field, we don't always have ideal conditions.

Jad: 8:13

Yeah, that's true.

Lilly: 8:14

What advice would you give for those situations where some mixing might be unavoidable?

Jad: 8:20

If you're dealing with a larger pit, say eight feet by eight feet or more, you might be able to use some uncompacted sandy loam soil around the root ball, with CU soil extending beneath the pavement.

Lilly: 8:34

But it's crucial to consult with the CU soil supplier and engineer to assess those site-specific conditions and get their recommendations.

Jad: 8:42

Sound advice.

Lilly: 8:43

Yeah.

Jad: 8:43

Consultation is key when you're dealing with a system this specialized, for sure. Now let's talk about irrigation and drainage. Okay, does working with CU soil change our approach to watering newly planted trees?

Lilly: 8:56

Like any newly planted tree, those in CU soil need regular watering to get established. However, the long-term needs will depend on factors like climate, tree species and the permeability of the subgrade. If the subgrade is impermeable, you'll need to consider drainage to prevent water logging.

Jad: 9:14

So it's about understanding the interplay of all those elements.

Lilly: 9:17

Right.

Jad: 9:17

Just like with any tree planting project, exactly. But what's exciting is that CU Soil seems to offer solutions for a whole range of urban planting scenarios.

Lilly: 9:26

Yeah, for sure.

Jad: 9:27

We've been focusing on sidewalks and tree pits, uh-huh, but where else can this technology be applied?

Lilly: 9:31

That's what's so innovative about CU Soil.

Jad: 9:33

Yeah.

Lilly: 9:34

It's not limited to sidewalks. It can be used in streetscapes, plazas, parking lots and even to revitalize existing trees.

Jad: 9:42

Revitalize existing trees.

Lilly: 9:44

Yes.

Jad: 9:44

Tell me more about that. Sure, I'm always looking for ways to give those mature trees a fighting chance.

Lilly: 9:49

Imagine a scenario where you have a mature tree struggling in a compacted tree pit. With careful air excavation, you can actually expand the root space and backfill with CU soil. It's like giving that tree a breath of fresh air and a new lease on life. Wow, you can even use CU soil to create channels, called breakout zones, that connect tree pits to adjacent green spaces.

Jad: 10:12

Okay.

Lilly: 10:13

Giving roots access to even more soil volume Got it.

Jad: 10:20

It's amazing what a little strategic digging in CU soil can do for a mature tree. That opens up so many possibilities for urban forestry projects.

Lilly: 10:24

It does.

Jad: 10:24

And speaking of expanding possibilities, we can't ignore the growing popularity of porous pavement for storm water management.

Lilly: 10:31

Right.

Jad: 10:33

How does CU soil fit into that equation?

Lilly: 10:35

CU soil and porous pavement are a dream team. You're probably already familiar with the stormwater benefits of porous pavement allowing water to infiltrate, reducing runoff, improving water quality. But CU Soil brings some unique advantages to the table. First, it's compactable, which makes installation much easier and more stable compared to those loose gravel bases typically used with porous pavement. Okay, and secondly, you're getting that dual benefit stormwater management and a healthy root environment.

Jad: 11:08

That's awesome.

Lilly: 11:09

It's a win-win that clients love to hear about.

Jad: 11:12

I can see how that would be a powerful selling point. You're addressing two major concerns with one solution, exactly. Yeah, you're addressing two major concerns with one solution, exactly. But I imagine there are some specific design considerations when combining CU soil with porous pavement right, you're absolutely right. Okay.

Lilly: 11:26

The mixed specifications are critical, as is the depth of the CU soil reservoir.

Jad: 11:31

Yeah.

Lilly: 11:31

You need to factor in the size of the storm events you're trying to mitigate. Okay, and the infiltration rates of the underlying soils Got it. Drainage also needs careful consideration, along with ongoing maintenance.

Jad: 11:42

Gotcha.

Lilly: 11:43

It's definitely more complex than just slapping down some porous pavement.

Jad: 11:47

This is where our expertise as arborists comes in right.

Roger: 11:50

Yeah.

Jad: 11:51

We're trained to think about all those interconnected factors that impact tree health.

Lilly: 11:55

For sure.

Jad: 11:56

But let's push the envelope even further.

Lilly: 11:58

Okay.

Jad: 11:58

Can we actually grow turf on CU soil, because that would be a game changer for those high traffic areas that always seem to end up bare and muddy.

Lilly: 12:08

You're thinking like a true innovator. Believe it or not, turf can actually thrive on CU soil. Really, research from Cornell's Urban Horticulture Institute has shown some pretty amazing results.

Jad: 12:20

This is blowing my mind.

Lilly: 12:21

Yeah, it's pretty cool.

Jad: 12:22

So we can literally have a car park with a lawn that can withstand traffic.

Lilly: 12:25

Yeah, pretty much.

Jad: 12:27

What's the secret here?

Lilly: 12:28

It's that compaction again. Because CU soil is so well compacted, it can handle occasional vehicle traffic without the soil becoming compacted and suffocating the turf roots. Plus, it provides excellent drainage, which is essential for healthy turf.

Jad: 12:43

So which types of grass are we talking about here?

Lilly: 12:45

Okay.

Jad: 12:45

Anything special, or just your average lawn seed?

Lilly: 12:49

Research suggests that tall fescue is a great option for northern climates.

Jad: 12:53

Right.

Lilly: 12:54

While zoysia performs well in the south Gotcha. These grasses are known for their durability and traffic tolerance.

Jad: 13:00

Yeah.

Lilly: 13:01

Making them perfect for those challenging urban conditions.

Jad: 13:04

I'm starting to see a pattern here.

Lilly: 13:05

Yeah.

Jad: 13:06

CU soil is all about challenging assumptions and finding innovative solutions.

Lilly: 13:11

For sure.

Jad: 13:12

It's giving us permission to reimagine the possibilities of urban landscapes.

Lilly: 13:17

I think that's a perfect way to put it. Yeah, I agree, now that we've covered the fundamentals of urban landscapes. I think that's a perfect way to put it. Yeah, I agree Now that we've covered the fundamentals of CU soil.

Jad: 13:22

Yeah.

Lilly: 13:22

Let's see how it performs in real world scenarios. Okay, these case studies highlight the diverse ways arborists are using CU soil to address urban challenges and achieve impressive results.

Jad: 13:33

I love a good case study.

Lilly: 13:34

Yeah.

Jad: 13:35

It's one thing to understand the theory.

Roger: 13:37

Right.

Jad: 13:37

But seeing how this technology translates into tangible outcomes is what really gets me excited. So where are we headed first on our CU soil tour?

Lilly: 13:46

Let's start with a project that might seem a bit unconventional at first.

Jad: 13:50

OK.

Lilly: 13:50

A parking lot in Ithaca, New York.

Jad: 13:52

The parking lot yeah, that's not exactly the first place that comes to mind when I think of lush green spaces.

Lilly: 13:59

Right.

Jad: 13:59

Isn't that a bit of a tough sell for clients who are looking for something more aesthetically pleasing?

Lilly: 14:04

It might seem counterintuitive, but that's what's so exciting about CU Soil.

Jad: 14:08

Okay.

Lilly: 14:09

It allows us to rethink those typically barren urban spaces and integrate trees in ways we might not have thought possible before. In this case, they divided the parking lot in half. One half got a traditional impervious asphalt surface, while the other half got a porous asphalt surface.

Jad: 14:27

Ah, so they were comparing the two approaches side by side.

Lilly: 14:30

Exactly.

Jad: 14:31

I'm guessing the porous asphalt allows for better water infiltration Right, which would benefit the trees, but was that the main focus of the study?

Lilly: 14:39

The real star of the show was the CU soil.

Jad: 14:41

Okay.

Lilly: 14:42

They excavated the entire lot to a depth of two feet and used CU soil as the base course for both sides.

Jad: 14:49

So even the trees on the traditional asphalt side were planted in CU soil. Yes, that's an interesting twist. Yeah, I'm curious to know how those trees fared compared to those on the porous side.

Lilly: 14:59

That's the surprising part. Okay, the trees on both sides have actually been thriving. The CU soil has proven effective in supporting healthy tree growth, even under the traditional asphalt.

Jad: 15:10

That's pretty remarkable.

Lilly: 15:11

Yeah, it is.

Jad: 15:12

It means that, even without a complete overhaul of existing infrastructure, we can still create favorable conditions for trees using CU soil.

Lilly: 15:21

Exactly.

Jad: 15:22

This could be a game changer for convincing clients who are hesitant to invest in more extensive renovations.

Lilly: 15:27

For sure.

Jad: 15:27

Okay, cool, but let's shift gears and move on to our next destination. Okay, mccarran Park in Brooklyn, new York.

Lilly: 15:35

From parking lots to streetscapes.

Jad: 15:36

Yeah.

Lilly: 15:37

It seems like CU soil is versatile.

Jad: 15:39

Very much so.

Lilly: 15:40

What were they trying to achieve with this project? Was it a similar side-by-side comparison? Like the Ithaca parking lot, this project focused on creating optimal conditions for a row of trees along a sidewalk. They installed a continuous trench of CU soil yeah, 24 inches deep.

Jad: 15:56

Right.

Lilly: 15:57

As the base course for the entire sidewalk on one side of the street.

Jad: 16:00

Okay.

Lilly: 16:01

Then they strategically placed tree pits with removable permeable pavers along that sidewalk.

Jad: 16:06

Okay, I'm visualizing this.

Lilly: 16:07

Yeah.

Jad: 16:08

So those trees essentially have access to a continuous, uninterrupted volume of CU soil beneath the pavement Right. It's like giving their roots a highway to spread out and explore Exactly.

Lilly: 16:22

They did On the opposite side of the street. They planted trees in a standard tree lawn.

Jad: 16:27

Gotcha.

Lilly: 16:27

This allowed them to observe the long-term growth and health of trees in CU soil versus more traditional setting.

Jad: 16:34

A classic head-to-head matchup, yep. So, after all these years, who emerged as the winner? Did the CU soil trees show a significant advantage over the tree lawn trees.

Lilly: 16:44

The trees growing in the CU soil are comparable in size and health to those growing in the tree lawn. So what's the big deal Now, you might be thinking wait, so what's? The big deal, but here's where it gets really interesting. Okay, ground penetrating radar data shows that the roots of the CU soil trees have completely colonized the entire profile. They're taking full advantage of that expansive underground network.

Jad: 17:11

So while we might not see a dramatic difference in the canopy size above ground Right, what's happening beneath the surface is remarkable For sure. Those CU soil trees have established this robust interconnected root system that's setting them up for long-term success.

Lilly: 17:28

Precisely.

Jad: 17:29

Yeah.

Lilly: 17:30

It highlights that CU soil not only supports healthy growth, but also promotes the development of these extensive root systems that contribute to a tree's overall stability and resilience.

Jad: 17:40

This is making me rethink my whole approach to urban tree planting.

Lilly: 17:44

I can imagine.

Jad: 17:45

I'm already picturing the possibilities.

Lilly: 17:46

Yeah.

Jad: 17:46

Okay, give me another case study. I'm ready for more CU soil inspiration.

Lilly: 17:50

Let's head back to Ithaca, new York, to a project on West State Street. Okay, in 1999, they decided to retrofit several blocks of the street and saw it as a perfect opportunity to incorporate CU soil.

Jad: 18:02

Retrofit. Yeah, so this involves working with existing trees, which always adds complexity to a project. For sure what were they dealing with in this situation.

Lilly: 18:11

They had a number of mature trees growing in existing tree pits along those blocks.

Jad: 18:16

Okay.

Lilly: 18:17

And their goal was to preserve those trees during their renovation.

Jad: 18:20

Makes sense.

Lilly: 18:21

They didn't want to sacrifice those mature trees for the sake of the streetscape improvements, right. So they came up with a clever solution.

Jad: 18:28

What was it?

Lilly: 18:29

They created these block-long continuous trenches of CU soil right up to the edge of the existing tree pits.

Jad: 18:38

So they essentially expanded the usable root zone for those mature trees.

Lilly: 18:41

Yes.

Jad: 18:42

It's like giving their root systems a much-needed expansion project. I'm assuming they also added new trees along those blocks.

Lilly: 18:50

You're right. They incorporated new tree pits along the sidewalk and carefully chose species that would visually complement the existing trees.

Roger: 18:59

Nice.

Lilly: 19:00

It was a thoughtful approach to creating a cohesive and vibrant streetscape.

Jad: 19:05

I'm curious how did this retrofitting approach perform over time? Were they successful in preserving those mature trees and establishing the new ones?

Lilly: 19:15

The project has been a resounding success. That's great. After 10 years, wow. Both the mature trees and the new trees are thriving, demonstrating that CU soil can be used to revitalize existing urban landscapes and support healthy tree growth for years to come.

Jad: 19:31

That's fantastic news.

Lilly: 19:32

It is.

Jad: 19:33

It shows that with some strategic planning and the right materials, we can create urban spaces that are both beautiful and beneficial for trees. These case studies are really opening my eyes to the possibilities of this technology.

Roger: 19:45

Yeah.

Jad: 19:46

I'm especially interested in those applications that go beyond the typical sidewalk planting scenario. Right, what else have you got for us?

Lilly: 19:53

Well, let's stick with Ithaca for one more stop on our tour.

Jad: 19:55

Okay.

Lilly: 19:55

This time we're headed to Green Street Okay, one of the busiest streets in the city, wow, and home to a major bus station.

Jad: 20:02

Okay, now that's what I call an urban challenge. Okay, we're talking high traffic, lots of exhaust fumes, limited space.

Lilly: 20:09

Yep.

Jad: 20:10

Not exactly the ideal environment for trees.

Lilly: 20:12

This is tough.

Jad: 20:14

What were they thinking when they decided to incorporate trees into this project?

Lilly: 20:17

This project, completed in 2003, was all about pushing the limits of what's possible with CU soil.

Jad: 20:23

Okay.

Lilly: 20:23

They wanted to see if they could create a thriving green space in one of the harshest urban settings imaginable. Wow, a thriving green space in one of the harshest urban settings imaginable. Wow, they installed an eight-foot-wide trench of sea soil, 24 inches deep, running the entire length of the street.

Jad: 20:37

An eight-foot-wide trench of sea soil on one of the busiest streets in Ithaca.

Lilly: 20:42

It's a big one.

Jad: 20:43

That's a bold move, yeah, but what about the trees themselves? Did they choose a super tough species to withstand those brutal conditions?

Lilly: 20:51

They definitely needed a tree that could handle the heat, so to speak.

Jad: 20:55

Yeah.

Lilly: 20:56

They went with chinkapin oak, a species known for its remarkable tolerance to alkaline soils and urban stresses.

Jad: 21:03

Interesting choice.

Lilly: 21:04

It's not a common street tree.

Jad: 21:06

No.

Lilly: 21:06

But it's proving to be a real champion in this setting.

Jad: 21:09

So how are those chinkapin oaks doing after all these years? Are they managing to hold their own amidst the hustle and bustle of Green Street?

Lilly: 21:17

They're more than just holding their own. They're thriving.

Jad: 21:20

Wow, that's great.

Lilly: 21:21

After 11 years, those trees are growing tall and strong, a testament to the power of CU soil to create resilient green spaces spaces even in the most challenging urban environments.

Jad: 21:31

I'm starting to think that CU soil is like the superhero of urban tree planting.

Lilly: 21:35

Uh-huh, I like that.

Jad: 21:36

It's overcoming obstacles left and right.

Lilly: 21:38

It really is.

Jad: 21:39

Okay, let's switch gears from busy streets to a more serene setting. You mentioned a case study earlier about a Katsura tree that was threatened by a plaza renovation. What happened there about?

Lilly: 21:50

a Katsura tree that was threatened by a plaza renovation Right. What happened there? That project at Cornell University's Mann Library is a perfect example of how CU soil can be used to protect and preserve mature trees during construction projects.

Jad: 22:00

Okay.

Lilly: 22:01

It's a scenario that many of us encounter in our work.

Jad: 22:03

Yes, for sure.

Lilly: 22:04

And it's always a challenge to find solutions that balance the needs of the project with the health of the tree.

Jad: 22:10

Absolutely.

Lilly: 22:11

Yeah.

Jad: 22:12

I know how heartbreaking it can be to lose a mature tree to construction.

Lilly: 22:15

It really is.

Jad: 22:17

So tell us how they managed to save this Katsura tree.

Lilly: 22:20

They were planning to build this new plaza adjacent to the library, and the initial excavation plan would have severely damaged the roots of this beautiful mature Katsura tree.

Jad: 22:31

It sounds like a disaster waiting to happen. It did. I've seen that play out too many times.

Lilly: 22:35

Yeah, me too.

Jad: 22:36

So how did they manage to avert this arboreal tragedy?

Lilly: 22:40

They got creative.

Jad: 22:41

Okay.

Lilly: 22:41

Instead of removing the tree or risking significant root damage, they decided to build the plaza on top of the existing root system, using CU soil as the key ingredient.

Jad: 22:51

Wait, they built on top of the roots. Yeah, I'm trying to wrap my head around this.

Lilly: 22:54

It's pretty wild.

Jad: 22:55

How is that even possible?

Lilly: 22:57

They used an air excavation tool to carefully remove the soil around the tree's root system.

Jad: 23:02

Okay.

Lilly: 23:02

Minimizing damage. Then they place a 12 to 15 inch layer of CU soil directly on top of those exposed roots and compacted it to create a stable base for the plaza.

Jad: 23:13

Wow. So the CU soil acted as both a protective barrier and a supportive foundation.

Lilly: 23:18

Exactly. That's brilliant yeah.

Jad: 23:24

What did they use for the plaza surface itself, did they?

Lilly: 23:27

have to do anything special to ensure the tree roots could still breathe and get water. They chose permeable pavers with open joints allowing water and air to reach the tree roots below.

Jad: 23:34

So it's essentially like giving the tree its own underground oasis right beneath a bustling plaza. Right, that's incredible.

Lilly: 23:41

Yeah, it's a good one.

Jad: 23:41

It's a testament to the ingenuity of the design team and the versatility of sea soil. Okay, you mentioned one more case study that I can't wait to hear about the car dealership with the turf parking lot.

Lilly: 23:52

Oh yeah.

Jad: 23:54

This sounds too good to be true, oh it's definitely real, okay.

Lilly: 23:56

This dealership in Birmingham, alabama, wanted to create a more attractive and environmentally friendly parking lot.

Jad: 24:03

Okay.

Lilly: 24:03

And they recognized the potential of sea use soil to help them achieve those goals.

Jad: 24:07

So they literally ripped up their asphalt and replaced it with a lawn.

Lilly: 24:11

Well, not the whole. Thing.

Jad: 24:12

Okay.

Lilly: 24:12

They actually focused on the median strip.

Jad: 24:15

Okay.

Lilly: 24:15

Which is a smart approach.

Jad: 24:17

Yeah.

Lilly: 24:17

They excavated that area and replaced it with CU soil Uh-huh, then laid down a beautiful lush lawn.

Jad: 24:24

And it can handle cars driving over it. Yep, that's pretty mind-blowing.

Lilly: 24:27

It is.

Jad: 24:28

What cars driving over it? Yep, that's pretty mind-blowing.

Lilly: 24:29

It is. What's the secret sauce here? It all comes back to that compaction Okay. Because CU soil is so well compacted, it can handle occasional vehicle traffic without the soil becoming compacted and harming the turf roots.

Roger: 24:40

Yeah.

Lilly: 24:40

It's also designed for excellent drainage, which helps prevent the lawn from getting waterlogged.

Jad: 24:45

So it's like a win-win-win for the dealership Right. They get this stunning green space that also functions as a parking area.

Lilly: 24:51

Uh-huh.

Jad: 24:52

And they're reaping the stormwater management benefits of a permeable surface. It's such a creative application of CU soil.

Lilly: 24:59

I agree.

Jad: 25:00

We've covered so much ground in this episode.

Lilly: 25:02

We have.

Jad: 25:03

From the science behind CU soil to its diverse applications.

Lilly: 25:06

For sure.

Jad: 25:07

It's clear that this technology has the potential to transform how we approach urban forestry and create more resilient, beautiful and functional green spaces.

Lilly: 25:16

I couldn't agree more.

Jad: 25:17

I don't know about you, but I'm feeling incredibly inspired to start incorporating CU soil into my projects.

Lilly: 25:23

Yeah, me too.

Jad: 25:24

It's like a whole new world of possibilities that's opened up. For sure For our listeners who are eager to learn more about CU soil. We've included links to resources and licensed producers in the show notes. Great, and here's a final thought to ponder what other innovative applications can you envision for CU soil? Maybe green roofs, vertical gardens? Oh the possibilities are endless.

Lilly: 25:48

Yeah, lots to think about.

Jad: 25:50

Thanks for joining us on this exploration of the fascinating world of CU structural soil.

Lilly: 25:55

It was my pleasure.

Roger: 26:00

Thank you for joining us Today. We reviewed Cornell University's CU structural soil guide, covering its composition, installation, maintenance and documented applications in urban environments. We also examined its role in supporting healthy tree and turf growth beneath paved surfaces and its benefits for stormwater management. We appreciate your attention and look forward to our next discussion. Thank you.