 Let's get started and learn about ornamental grasses for rain gardens and here to teach us is Dr. Esther McGannis. Esther is an NDSU Extension Horticulturist. She's the Director of the NDSU Extension Master Gardener Program and she's an Associate Professor in the Department of Plant Sciences. Esther and her team of graduate students, they evaluate ornamental and native plants for pollinator attraction, rain garden environments, and for commercial flower production. Esther welcome to the forums. Thank you, Tom. I'm really happy to be here and it's actually quite relevant because here we've got, it's actually raining and we're going to talk about rain gardens tonight and our evaluation of ornamental grasses. And this very much is a team project. I work with Erin Day. Erin Day is our soil scientist in the soil science department and we co-advise Randy Nelson. Tonight I am going to be sharing with you Randy's research. So instead I'm presenting for him tonight and we're going to talk about rain gardens and a rain garden is a bio retention basin, a basin in the landscape to collect storm water runoff. And the reason we do this is we want to keep the water on the property. We want, we don't want to overload the storm water system. And in addition, we want to keep the pollutants in place. Now as you can imagine when we have a rain event, you know, you have water falling on impervious surfaces such as buildings, you have them falling on sidewalks, driveways, streets, and parking lots. And this all goes into the storm water system instead of infiltrating into the ground. We want it to infiltrate and we want to keep the pollutants in place instead of sending them to our lakes into our rivers. So pollutants would include like de-icing salts that you would find on your driveway and sidewalk. They would also include petroleum products, you know, as you can imagine your truck sitting on your driveway and you've got oil leaking. So we don't want that going into the storm water system. If we can, we'd like that to go into a bio retention basin such as pictured here. Now this is a residential rain garden, most likely in Maplewood, Minnesota. And as you can see, there is no curb anymore. And this was specifically designed to have the storm water collect in these rain gardens. But there's all different kinds of rain gardens, including parking lots. And here we have the rain water would flow from the parking lot into this area in between the rows and would collect right there and keep those de-icing salts and the petroleum products in place. We can even have downspout gardens. And with our downspout gardens, it's all about keeping the water in place to allow it to stay there. Now the problem is that we've got all these governmental entities recommending the building of rain gardens and they're recommending all sorts of plants. But there's no scientific research on which to base those recommendations. The recommendations are based merely on how well they do in a wetland status. But we really don't have scientific studies on this. And there's also the fact that we have different climates. In Minnesota, it's quite a bit wetter than it normally is in North Dakota. In North Dakota, our rain gardens may have a really good thunderstorm, but then stay dry for weeks. So our plants would experience cyclical saturation followed by maybe long periods of drought. We wanted to study plants to see how well they would take that double whammy of flooding and then alternating periods of drought. For Randy's project, we first worked on native sedges and ignore the scientific name. So we worked on different sedges. And we looked at their wetland status. So we worked with porcupine sedge and palm sedge. And these are obligate wetland plants. And these plants, you would always find in a wetland situation. And then we have at the bottom of the table, we've got Pennsylvania sedge, which you would never find in a wetland. It would only occur in an upland situation. And in between, you have plants that are an intermediate status, like faculty of wetland, they're more likely to occur in a wetland, but you'll still find them in in drier soils. And then faculty of means you're equally likely to find a plant in a saturated wetland condition versus a dry upland situation. So we took these seven sedges, and we looked at alternating periods of flooding and drought. And these, these were really punishing, punishing experiments. Plants are subjected to either two days flooding or seven day flooding. And then we had three different droughts that they drought set points. There was either mild drought at 15% volumetric water content. We had moderate drought at 10% and severe drought at 5%. And, you know, going through several cycles, a minimum of four cycles for all of them. So in some sense, we were trying to, we were trying to take the plants to the limit. Now, if we had been doing animal studies, they would have called PETA on us. But fortunately, we were just working with plants. And what we found is that the obligate wetland plants did not do as well. Instead, it was the intermediate plants. The faculty of wetland and the faculty of plants that were in those intermediate categories that could take a more adaptable situation. Now, here's palm sedge palm sedge, very much a wetland plant. And you can see on the left, we've got just a control plant, which did not go through flooding and drought. And then we have the remaining three plants. They went through alternating periods of two-day flood and mild drought is number two, moderate drought is number three, and severe drought is number four. And you look at number three, number three and four, they are really, really stressed and they are showing a lot of dead tissue. So obligate wetland plants were not necessarily the key here. And compare that to a faculty of wetland plant. This is Plains oval sedge went through two days of flooding. And then if we look at it, you can see that the plants really, really did well under mild and moderate drought set points. Once we got to the 5% volumetric water content, the plant is definitely more stressed. You can see it's wilting, but it's not dying like palm sedge was in a similar treatment. All right, so we took that and instead we wanted to look at ornamental grasses. So we're now going from Randy's master's project to the beginning of his PhD project. And we were looking at commonly found cultivars in the retail trade, including pixie fountain, tufted hair grass. We looked at Northwind switch grass, red October, big bluestem, perporescence, or some of you may know it as purple flame grass, blue heaven, little bluestem, blonde ambition, blue grandma grass, and Carl Forrester, feather, reed grass. Once again, we're using the wetland indicators. We did not look at obligate wetland plants because we couldn't find any ornamental grasses which normally occur in wetlands. But we were thinking that based on our previous study, pixie fountain and Northwind would do best because they were in those intermediate categories of facultative wetland and facultative. The rest of the plants were more used to much drier well-drained soils. So let's see how well we did in our hypothesis. Now these are pictures of the grasses that we used in our study. You can see they're all very, very attractive and would look very good in a residential rain garden setting. So the design for the ornamental grass project was very much very similar. You know, we had two flood durations, two day and seven day, but we did condense the drought set points into two. We had 14 percent and 7 percent. So mild drought and severe drought is what we used, and then we compared that to a well-watered control. I'm going to show you a couple of figures here. You're going to see that in our big, in our dark blue columns, we have the severe drought setting, and then in the light blue was our mild drought setting. Once again, we've got all of our grasses listed as well as the wetland status. We had four that actually did better than the controls under mild drought setting. We had the tufted hairgrass. We had Chinese silver grass, blue gramma grass, and feather weed grass. But by the time we got to the severe drought setting, we saw that the plants suffered. They produced a lot less shoot biomass. So that's the above ground leaf growth. They produced a lot less because of drought, but that's to be somewhat expected. We looked at root biomass. How much root tissue that was, and that was adversely affected by the 14 percent volumetric water content and also adversely affected by the severe drought set point. This wasn't necessarily telling us all that we wanted to see. What we found is that a picture can tell, this picture is worth a thousand words. Here's Chinese silver grass or purple flame grass, and it's grown under the mild drought condition, and you can see the plants are doing splendidly, doing really well. Now let's contrast this with our severe drought, regardless of whether it was exposed to two days of flooding or seven days of flooding. When it was followed by the 7 percent volumetric water content, we started seeing a little bit of dieback going on. They're actually quite a bit of dieback going on. This is where we really started finding our results by doing damage ratings. When we looked at the visual damage ratings, first I should explain the visual damage rating. It's from 1 to 10. 1 is no damage, and 10 is severe damage. Actually, most of the grasses did quite well. The exceptions being tufted hair grass, really did not take the drought well, and blue grama grass. The rest of our grasses that have a sea above them did quite well. They did splendidly under the mild drought, but showed more damage under the severe drought. Now some of you may be like, well, I'm not going to be doing a rain garden. I live in western North Dakota, and it seems like it never rains here. We can still take findings from our research, and it will be useful for you because we did this alternating flooding and drought. We were exposing them to really, really rigid conditions, and they really took a lot of drought, which can be applicable if you're looking to plant a zero-scape. We have purple flame grass here, and I'm going to talk about the ones that I'm going to recommend. We've got purple flame grass, which is a warm season grass, and it has these wonderful seed heads which are produced in late August and into September. This is a Zone 3 plant, and it's hardier than the other miscanthus species that we grow here in North Dakota. Of all the miscanthus species, this is the one that I recommend, and we've shown that it will take mild drought quite well, but may need a little bit of irrigation when it comes to more severe drought, but still a very reliable grass, reliable fall color, and it does have small rhizomes, but it's not invasive. The small rhizomes will expand the width of the plant as it gets older, but it's really not going to take over your garden. Red October, our big blue stem did very well. This is a Zone 4 plant, and it's beautiful in the landscape, four to six feet tall, beautiful height on it, beautiful seed heads that look like a turkey foot, very much a warm season grass that really looks its best in late summer going into fall, and the grass at that time will turn red. It'll have that beautiful red coloration. You're getting that fall color in an ornamental grass. It's a clump former. The one downside to red October is it will self seed a bit. Another one to recommend that takes drought quite well is our blue heaven, which is little blue stem. It starts off the season beautiful, beautiful blue-green coloration, and then it starts to develop anthocyanin pigments, which is that red coloration in fall, just gorgeous, gorgeous. It's not going to lodge much. It's not going to lodge. It's going to stand straight up, and it's less hardy in northern North Dakota, but it does quite well in the southern half of the state. So beautiful grass for whether you're going to put it in your rain garden or whether you're going to put it in your environment that may be a little on the drier side. Northwind switchgrass also did very well in our studies. Zone three, a plant standing four to five feet tall. The seed heads aren't as attractive as some of the other grasses, but what's nice about this is that it stands straight up and down like an exclamation point, nice columnar form, and you can kind of use this as a living fence. You can use this as a backdrop, but just surprise that we can use switchgrass in different settings. We can use it in the rain garden setting. We can use it in aziric or drought setting, and it does quite well. And that brings us to Carl Forrester. I have a love-hate relationship with Carl Forrester. For me, I feel like it's overused in the landscape, but it really showed its colors in our studies here, did really well in the moderate drought situation, and it seemed to do okay with flooding. I was not expecting it to take flooding the way that it did and to bounce back, but it did. So this is one of those bullet-proof grasses. It looks great in the landscape, nice clump former, four to five feet tall, and hardy to zone three. I'm going to throw in a bonus plant, butalua gracilis, blonde ambition. This did not do as well in our rain garden studies. It was less tolerant of the flooding aspect of it. However, Randy has gone on to do other studies beyond the rain garden saturation and drought study. We're also looking at salt tolerance, because as you can imagine, salts accumulate in our rain gardens from all those de-icing salts, but blonde ambition did really well under fairly high salt concentration. And look, it's absolutely gorgeous. So for those of you that are living in western North Dakota that may have saline soils and are struggling with your ornamental landscape, would really recommend butalua gracilis, because it does well in those saline soils. So here's another picture of blonde ambition, blue gramma grass, just absolutely gorgeous having those really unique horizontal seed heads that it holds up. So in conclusion, these are highly adaptable grasses, adaptable to cyclical flooding and drought. You know, five of the seven I would recommend in a rain garden setting. We did see that severe drought. I mean, we really took these plants to the limit with severe drought, did reduce their growth and their ornamental value, but that's to be expected. Most plants would then be able to take that mild to moderate drought. However, if we get into a really severe drought like we had last year in western North Dakota, at that point you may need to supplemental irrigate your rain gardens and if you have these plants in your ornamental landscape. So you're going to see more results to come. We've got a submersion study you just completed and the salt tolerance study. And right now we've got a study seeing how well these plants tolerate petroleum. So I want to acknowledge the North Dakota Specialty Crop Block Grant and I'd like you to take our survey. So anytime we receive funding from a grant agency like the Specialty Crop Block Grant, we have to show that we have shared what we've learned from our experiments with the general public. So please take the survey which will show up in your chat box and I want to thank you for listening and thank you for tolerating my technical difficulties here. I have not worked on this computer setting here in quite a while and something was totally off, but thank you for your patience. Okay, thank you Esther and we do have time for some questions. Let's start with others. Question about from Minot, are any of the grasses tolerant of partial shade? Yes. Remember that Dishompsia or that Pixie, the Pixie Grass, that one will take moist shade and it does quite well. So I would say partial shade, I wouldn't say deep shade, but partial shade, the rest of them are going to be full sun exposure. Here's a question about what length of time is one full cycle and how long is the drought portion of that cycle? All right, so it was really very much individualized based on the plant. So we allowed the plant to naturally dry down to the drought set point and that was measured using one of the monitors that we had. So some of the plants went through more cycles than others, but they all went through the same time period. So we ended the experiment for all the plants at the same time period, but some of the plants cycled through faster based on how fast they dried down and how fast they used the water. So it really varied by plant. Esther, can these ornamental grasses be split and transplant? Yes, yes. These grasses can definitely be split and transplanted. You can do that in early spring and that's a really nice time to do it before they really get going. And then make sure that you get rid of the woody parts, the parts that may be a little less vigorous than the newer growth. But yes, they can be split. How about there's a question about was the study conducted in a greenhouse or was it conducted outdoors? We conducted this in a greenhouse because we're going full blast year round with our research. And we wanted to be able to control the amount of water and drought and we could not do that outdoors. So very much a controlled environment. How about is north wind switch grass invasive? North wind is not invasive. I have not had problems with that. I've not really seen them either. I've not seen them self seed. It's very well behaved, well mannered. It just stays put. There's a question. Are you doing any seed trials on these ornamental grasses, Esther, for the public? We're not doing any seed trials because these are all cultivars and there's intellectual property there. So we're not. And plus there's also the fact that with them being cultivars, if we propagated them from seed, they would not come true to type. It would not be the same genotype as what you see here. Is prairie drop seed invasive? A prairie drop seed is a native. And we did initially include that in our studies. For us, it was so slow growing that we dropped it from our trial. So I would not consider it invasive, but it does take time to get established in the landscape. It is one of my favorites, but it's going to do better under really dry circumstances. There's a question. This person's looking for the purple flame grass that you talked about. But when she sees it in the catwalks, it says it's going to ship in autumn. Is that true? I don't think so. I mean, this is probably one of the most common grasses that we grow. Sometimes it's called red flame grass. You may want to search by its name, by its Latin name, which is miscanthus, and use the cult of our name, perporescence. It's all over North Dakota. I mean, if you can't find it in the catwalk, go to your garden center. I'm sure they would have it at your local garden center. How about with that blonde ambition? We have one gardener who says she just can't get it to grow. So she's frustrated by it. But another gardener says there's interest in collecting the seeds of it, but would that be a good idea? Or is that the problem that it won't, it won't resemble its parent? It won't necessarily resemble its parent. It may not have as good a characteristics as the cultivar. I mean, you're certainly welcome to experiment. We encourage people to experiment and to start seeds and such, but it's not necessarily going to be the exact same. With the cultivar, we essentially select a certain genotype and it is then propagated by tissue culture or division to maintain the genetics of it. And what hardiness zone is that blonde ambition? Oh, I'm, I'm trying to remember here zone three or four, I believe. Okay. We haven't tested it for hardiness. How about, do any of these ornamental grasses do well in planters? In planters, I like to see more of the annual grasses in planters because the problem is that a lot of individuals keep their planters outdoors. As you can imagine that freezes and then it doesn't, it's not going to be able to survive the winter. Now, at the same time, you're not going to bring a big planter into your house. So I would say stick with your annuals because it's just more problematic if you're growing them in containers. Okay. Here's some non-grass questions here. You had a beautiful Carl Forster slide and next were some pom-pom-looking flowers. Do you know what they were? Are those ornamental alliums? I can't remember. It was either alliums. I think they were probably ornamental alliums if I'm remembering correctly. Yes, I love alliums. To look and to eat. Yes. Yes. How about as for what some of your favorite non-grasses that tolerate cycles of flooding and drought? Okay. Have not tested those. What's your favorite? Come on. You gotta have some favorite. You're planting ring gardens all the time. You gotta have some. Well, if it was your backyard, what would you plant? Well, I'm trying to think here what I would plant. I've seen Joe Pie weed actually do quite well in that type of setting. Iron weed does well, and it all depends on the depth of your rain garden and such. Some of the herbaceous plants may do better, more at a higher elevation as opposed to being down towards the bottom of your rain garden, but there are a lot of different rain garden plants that would do well, but Joe Pie weed I think is one of my favorites. How about, let's see here. Getting near the end here. Do you want to make sure I don't miss any? So, there's a question about the invasiveness. Will the cattle I'll tell you about if it's invasive and does it invade both by seeds and by the underground rhizomes? There are two kinds of invasiveness when it comes to grasses. Yes, I mean there's some that self seed really prolifically, and then there's some that spread by rhizomes. There is that miscanthus sacrafluorus. That's one of, I'm trying to remember the common name for that. That's one I would consider to be invasive, and we did not include that in the study. That's the one that you see growing in old abandoned farmsteads, and it's taking over the whole ditch. Now, we don't work with those types of grasses. We only work with grasses that we would consider non-invasive because we don't want to contribute to the problem. So, nothing that I'm recommending here is invasive. Just to talk to the people who are asking questions, it seems like that's the keyword invasive that they would say in a catalog or whatever as far as worry about spreading out of control. Do you have any comments about swamp milkweed? Swamp milkweed. I love swamp milkweed because swamp milkweed does not spread out of control. Swamp milkweed will stay put. I'm less of a fan of the common milkweed in an ornamental landscape situation because of the common milkweed spreads by rhizomes and will eventually take over a large area. Now, if that's what you want, that's totally fine with that because it certainly nourishes the monarchs. But in a small urban setting, in a small garden, common milkweed in contrast is very well behaved. Okay. How about when do you cut down ornamental grasses at the crown level? With ornamental grasses, you have a couple of options. I like to keep my ornamental grasses up over the winter because they provide winter interest. I leave my coral forest or I leave my other grasses up. Usually, about end of March, beginning of April is when I cut them down to facilitate new growth. There's an easy way of doing it. I use a little rope, tie off, try and tie it off and tie off the grass so that I can just hack it off at the bottom and then I've just got that one big bunch of them. Okay. We just got a couple of questions here. Where was that first garden you showed? That was in Minnesota, you said. Was that right? That beautiful one at the hostel? Yes. That's most likely maple wood because they have a series of rain gardens in that community. And do you have a good source if you wanted to buy swamp milkweed? Swamp milkweed. Really, your local garden centers are really starting to carry these now, so I would try and see if your local garden center has it. If not, there are native plant nurseries and one of my favorites being Prairie Moon out of Winona, Minnesota. Okay. Thank you. Astrid, thank you for all that great information. Let's just hope we get lots of rain so we can have our rain gardens. That would be wonderful. Yes. Okay. Thank you.