How to Create a Green Roof

[Music Playing] Dave: Hi! I am Dave Epstein, this is Growing Wisdom. We are ere wit Ralph Schilling at Garden in the Woods, New England Wildflower Society property and we are sitting at the base of the shed here. And up there, you got plants in the roof. This is called the green roof. Ralph: Yes, that is right. This is New England Wildflower Society’s first green roof and like you said, this is an existing shed. It has been here long time and it has been part of our nursery. Dave: My fear would be there is too much moisture on the roof. Right? So, how do you medicate that? Ralph: There has to be a moisture barrier between your green roof and your existing roof that you build it in your existing roof. So we use galvanized steels with corrugated sheeting then on top of that we put trays, each of these sets of plants were in four different trays that has a grating on the bottom, so it can drain. And then around that, we built a simple wooden frame that is seen on the outside. Dave: And did you have to use a lighter soil? Ralph: Well, we did. We tried to lighten the soil up by using a lot of pearlites, good for drainages, good for balancing the moisture and keeping it loft. Dave: What type of plants did you used up here? Ralph: This entire site is all northeastern native plants and the other site is all southeastern native plants. This is the north side that is the south side. These are all coastal plants or plants from upland ridges that are used to really dry, really exposed conditions. Dave: And you guys have a list of plants that folks can actually use. Yes, on the website, we got a list of plants. So, if you are interested, people can do that and is there any plant to stay away from? Ralph: Well, you might stay away from mostly tap rooted plants. Any plant that loves moisture is not going to work for you and ay plant that cannot stand a lot of wind is not going to work for you. Dave: And we are going to go up there and you are actually going to fill in a spot today. Ralph: Yes, I have a couple of bare spots that can use a couple of more plants. Dave: So, tell me, what are we doing here? Ralph: This is spreading aster and I am putting a couple of more to fill a couple of more spaces. Dave: And I noticed you put down the leaf mulch which is gray. You have recycled the leaves. So, we got about four inches worth as well right here in the roof. And that is enough for the plants. Ralph: Yes, it is plenty. Dave: Do we have to worry about watering this or is nature kind of do its thing? Ralph: We watered it once when we put it in and that is it. Dave: Wow! That is pretty amazing! So, not only is it creating a green roof but it is low maintenance in terms of water, as well. Ralph: Yes. Dave: Now, if you did this on a building in which you lived, would that keep the inside cooler? Ralph: Yes, a lot. It significantly reduces cooling and heating as well. Because the heat lost in the winters is blocked by this layer. Dave: Well, Ralph thanks a lot! This is really cool. I really like this. Pretty neat stuff, huh! All the way up on a roof, you can actually grow plats and you only needed four inches of soil to do it. We hope you come back every week for all of our tips, hints and helps here at growingwisdom.com. And check out all the ways you can go green at newenglandwild.org. [Music Playing]