Unveiling the Secrets of Rain Gardens

Episode Description

In this episode of “The Evergreen Thumb,” we delved into the fascinating world of rain gardens. Our discussion covered the fundamental concepts of rain gardens, exploring their design, purpose, and the positive impact they’ve had on local environments in Washington State. We provide insights into the plants best suited for Pacific Northwest rain gardens and share practical tips for how they can help manage water runoff, especially in urban areas.

The episode also highlighted the role of rain gardens in supporting biodiversity and promoting ecosystem health. We addressed common misconceptions and offered resources and guidelines for designing and building rain gardens at home. Our expert guest, Valorie Savisky, shared research-backed benefits and emphasized the role rain gardens can play in improving our water quality.

This episode aims to empower gardeners with the knowledge and tools to cultivate beauty while practicing sustainability through the art and science of rain gardens.

Valorie Savisky was born and raised north of Burien, WA. She graduated from Evergreen High School and received a BA in Accounting from Golden Gate University, San Francisco, and a master’s in Federal Taxation from Golden Gate University, Seattle. She was a self-employed CPA for 33 years. Val became a certified WSU Ext MG in Kitsap County, WA, in 2019, where she first learned of rain gardens. She then moved to Ocean Shores in 2020 and then to Elma, WA, in 2022. She is very active in Elma demo garden since 2020, was involved with intern training in 2022, and is very involved with the workshops in greater Grays Harbor county in 2023. Her Rain Garden was featured on the 2023 Annual Garden Tour in Elma.

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Transcript of Rain Gardens

Erin: Welcome to the Evergreen Thumb episode 15. My guest today is Valorie Savisky.

Valorie is a WSU Extension Master Gardener in Grays Harbor and Pacific Counties. She was born and raised north of Burien, Washington, and graduated from Evergreen High School. Val received a BA in Accounting at Golden State University, San Francisco, a Master’s in Federal Taxation from Golden State University, Seattle. She was a self-employed CPA for 33 years.

Val became a certified WSU Extension Master Gardener in Kitsap County, Washington in 2019, where she first learned of rain gardens. She then moved to Ocean Shores in 2020 and then to Elma, Washington in 2022.

Valorie is very active at the Elma Demonstration Garden at the Grays Harbor County Fair since 2020, and was involved with intern training in 2022. She is very involved with the workshops in the greater Grays Harbor area and her rain garden was featured in the 2023 annual garden tour in Elma. And if you haven’t guessed, Val is here today to talk to us about rain gardens.

Val, welcome to the show.

0:01:07 – Valorie Savisky Thank you, Erin, thanks for having me.

How Valorie Got Into Rain Gardens

[0:01:10] – Erin All right to start off, why don’t you tell us a bit about yourself and how you became a master gardener and got involved with rain gardens?

[0:01:17] Valorie Savisky: OK, well, I got involved with rain gardens way before I got involved with master gardeners. But I was living in Kitsap County and a friend of mine wanted to build a new house and the county came to her and said we are requiring rain gardens for all new construction in this area. So I kind of helped her with the rain garden and then she found a lot of information on the Kitsap County Conservation District website. That was fantastic.

So that led me into the Master Gardener Program in Kitsap County, where I was certified in 2019. Then after that, I went to Eugene, which is in Oregon, Lane County, and they also require rain gardens for new construction and residential and businesses. Then I moved to Grays Harbor. I’m hoping I’m settled now in my retirement. So that’s that piece.

[0:02:38] Erin: So can you tell us about the first rain garden you said you worked on that was up in Kitsap County? Can you tell us a little bit about that garden?

[0:02:47] Valorie Savisky: That was a new house that was on undisturbed land. So I was involved in the excavation, which was very complicated there because the soil is a lot different than what I have here in Elma. Specific sorts of soil were brought in for each level, so they’d start with rocks and then sand and then to make it as permeable as possible and then heavily composted in the areas where the plants would be. So that was kind of over my head back then. But then I did a lot of studying when I was in Eugene and even got to be familiar with the city regulations for rain gardens, because we had a big one where I chose to live and nobody else knew anything about it.

And then I moved up here to Ocean Shores, which is all sandy, so I built one there. I just kind of threw one together and it worked really well. And now I am in Elma where the soil is the old river bottom from the Chehalis River when it came across Elma. Now it’s a ways away, but I have a lot of that. The soil is fairly fertile, there’s tons of pea gravel in it and there’s also a lot of rocks. So that will play in as we continue into how we build a rain garden.

What is a Rain Garden Exactly?

[0:04:51] Erin: OK, so let’s back up, and I guess we probably should tell our listeners exactly what a rain garden is.

[0:04:57] Valorie Savisky: A rain garden is, very simply put, a water filtration system, and so, as our land has, if you’ve ever hiked in the Cascades or in the Olympics, many of the trails really have just lush soil and are very bouncy, and so I’ve learned a lot as a Master Gardener about healthy soil principles. So before we started developing, the stormwater was filtered and purified and slowly filtered through all of that undisturbed organic matter in the forest before it hit the waterways.

Now, with extensive construction, stormwater runoff is one of the major pollutants, and what goes with that runoff is our chemicals and pesticides and pollutants of a lot of different sources from a lot of different sources. So what the rainwater, the rain garden, does is it slows down the flow of stormwater. The plants and the heavily composted soil in the rain garden filters the water, which adds back to the groundwater, and it also slows the runoff into our rivers and larger waterways which are close to the ocean.

We have the Chehalis River here, we have the Satsop River, we have tons of creeks, and this isn’t as highly developed as, say, for instance, King County or Thurston County or Kitsap County. But there is a place in every community for residential rain gardens. They’re not required here yet in Grace Harbor County, but they are in King County and specific parts of Kitsap County.

[0:07:32] Erin: You said you just constructed a rain garden at your home in Elma, and it was featured on the 2023 annual garden tour hosted by the Grace Harbor Pacific County Master Gardeners.

[0:07:47] Valorie Savisky: Correct.

[0:07:49] Erin: But it was still a very young garden at that time.

[0:07:59] Valorie Savisky: I was asked by our garden tour, We have a person in our Master Gardener Program here in Grays Harbor in Pacific Counties, and I think she said it jokingly at first, “Would you have any interest in being on the tour?”, or “you need to be on the garden tour”. And I said are you kidding? When I moved in this house in November of 2022, it was a flat lot, which I liked. It was almost a triple city-wide lot, so it’s large, but all it had on it was weeds, grass, and tons of dandelions.

So, as a Master Gardener, I’ve been very interested in getting rid of grass, which, in essence, is a dead ecosystem and we usually use a lot of pesticides and fertilizers on it, so they’re pollutant factors. There really are. There are a few insects, but it’s not a biodiverse ecosystem in the least. So my immediate thought was I’m going to get rid of all the lawn. I’m going to build a rain garden. My yard is separated into three distinct parts.

This house was built in 1900, and it’s still the original. I think they call it pier and plank. It does not have a foundation. So my main intent was to get the water away from the foundation, to keep that moisture as much as I could away from getting underneath the house. So that played right into my plan. I really wanted to build a rain garden.

So I moved in November of 2022 and the home and garden show for the garden tour for 2023 was in the following: what was it? July, I think like the third week of July. So I thought, oh, I don’t know, I’m going to get this done. I hired an excavator to scrape off the sod and weeds and dug the initial hole. So that’s how it got started. But then I did all the other pieces of the building, which we’ll talk about.

Planning a Rain Garden

[0:10:49] Erin: So let’s start with planning the planning process for a rain garden. How, what was the process that you went through to decide? Did you know how big it was, or did you know how much space you needed, or what plants you needed?

[0:11:03] Valorie Savisky: At this point, I’m going to plug the WSU Extension publication called the Rain Garden Handbook for Western Washington. So that was done in conjunction with the Department of Ecology and the Kitsap County Conservation District and actually the extension the program coordinator for Master Gardeners in Kitsap County headed up the project in conjunction with these other departments. So it’s just a very awesome handbook. It covers the four main things: planning, construction, building, planting and maintenance. And it also includes an amazing appendix for native plants and their other resources, their other appendixes for county resources. So every county has a conservation district and so we’ll talk more about that later. But so that’s where I started.

The first step is planning. So the very first thing to do in this the perfect time of year to do it is test the drainage of your soil, and the handbook gives explicit is that right? It gives extensive instructions explicitly, that’s the word of how to do that. So, very simply, you measure the areas and square footage of whatever you want to drain into that, into your rain garden, and mine is just a little bit of sidewalk, mostly rough, so I’ve connected all of my downspouts to pipes that run into the, into the rain garden. I discovered that my drainage when I dug so you dig a hole of certain dimensions and see how quickly it drains, and my soil happens to drain, mine is off the charts, fast. So the handbook also contains areas, all the areas from the entire West Coast of Washington, as to their rainfall percent or the inches of rainfall, and so there’s charts that tie in the rainfall with your drainage rate and that’s how you determine how big your rain garden is.

So mine ended up to be because my house is especially long and I have a lot of roof area mine ended up to be 400 square feet, and so it’s approximately 10 by 40, but I’ve got it kind of shaped into an hourglass, so it’s a little more interesting than just a rectangular hole. And what I found since is that my drainage rate is so fast here, which I’m delighted about. I mean, there are good things and bad things about that. The size of the rain garden didn’t have to be 400 square feet, so in consequently, I built a much smaller one on the other side of the house to drain two downspouts into, and it’s only I think it’s like maybe the 100 square feet at most, and I never have sitting water, which is the, which is what you want to accomplish with the size and the depth of the rain garden. This is not for sitting water, because we don’t want mosquitoes to propagate, and so the water needs to drain off within 18 or 24 hours so that doesn’t happen.

[0:15:40] Erin: Okay. So once you plan the initial layout or size and depth, and then you had soil brought in as well.

[0:15:49] Valorie Savisky: I did not. The handbook suggests strongly and I do too as a Master Gardener that you need to know what your soil content is. Conservation districts do soil tests. They can tell you what the content is basically and what the pH is.

If you have clay soil, if it’s predominantly clay, then it’s not a good place to build a rain garden. Clay soil is good because it retains moisture, but it doesn’t drain very quickly. So a rain garden, you’re on a time limit for drainage, so you can, in that case, you can dig out your native clay and refill it with recommended soil types that are also listed in the handbook. For me, I was able to use my native soil and the other big component of soil in a rain garden is adding. So it’s soil, whatever the type, whether it’s native or you’ve brought in special soil 65% soil along with 35% compost. I dug out, I had the excavators pile up the native soil and I actually strained literally strained all the rocks out of most of it and then refilled the depression I made in the soil with, tried to try it as closely as I could to get it to 65, 35 combination of compost and native soil. So for me it was not costly, except for hard work.

[0:17:59] Erin: I was going to say that’s a time-intensive undertaking.

Choosing Plants for the Rain Garden

Yeah, so once you’ve finished planting the structure of the garden itself, how did you go about deciding plant choices?

[0:18:19] Valorie Savisky: Alrighty, plants. I’m a native plant enthusiast and the suggested plants in the handbook and on other college extension websites that I’ve looked at recommend native plants. Number one, they’re most adaptable to the climate in that area and also with climate change progressing. Annual rainfall is just not, it’s not easy to calculate. So native plants are used to drought, they’re used to rain, I mean in particular times of the year, not steadily one or the other.

In Eugene, I had the privilege of learning about grass-like plants used in rain gardens and they used mostly Juncus and kerricks, which are their sedges and rushes. I love the grass-like plants and they are the most hardy and the most adaptable to drought conditions and very wet conditions. So most hybrid plants don’t like wet feet. And the rain garden has three specific areas. The area one is the bottom of the rain garden, which is the most wet, and then or the most dry, depending on the season, the sides are considered area two, which are less wet and less dry, and then area three is the top ground level of the structure.

So a rain garden always consists of a depression in the ground, so you’re always going to have level one. I don’t have a lot of level two because I just didn’t have the space. But I have a lot of level three and so I have mostly grass-like sedges and rushes only in level one. I have a few native spirea in level two. In level three I have non-native pollinator attractors a couple of different types like Monarda and Lobelia, and I also have well, I have mostly natives, like right now I’m looking at my Mahonia, I have a large Mahonia, I have a fringe cup, I have, oh my gosh, I have a Pacific Ninebark, I have a mock orange, I have avens, broadleaf avens and all of these are natives.

But so for the garden tour in July, we had a heatwave in May so I did not want to put brand new baby plants and all of them were like an inch tall. I did not want to plant them in that heat wave, so I waited until June when it cooled down and started, or probably the end of May and started raining more. So there was not much showing above the ground. But the great thing about the grass-likes they have I was able to find a native plant nursery, which unfortunately is not in business any longer, here in Puget Sound up in Olympia, and they planted in containers that were only about an inch and a half to do two inches wide, but they were 10 inches long so I knew I had really healthy roots, so I wasn’t worried too much about them and the others came in various root lengths.

The great thing about planting natives is they require much less and less watering. As they get older, like within three years, they shouldn’t require a whole lot of maintenance at all. So I had to water a lot last summer and I felt guilty about it, but I knew that’s going to turn around in another two or three years, so that’s another good thing about having natives.

[0:23:38] Erin: A lot of those, um the plants that you mentioned, a lot of those are pretty good size shrubs or will be pretty good size shrubs, yeah, and the Mahonia and things like that Ninebark, especially. I just did an episode on xeriscape gardens and so kind of the same thing. Once it becomes mature, you know it doesn’t have to be a boring garden. There can be lots of color and lots of variety.

[0:24:27] Valorie Savisky: Exactly. Yeah, and that’s what I’m hoping for. I’m also very aware that I’ll be transplanting a lot, because I put in as many plants as I could in the rain garden area, just so it looked like something for the rain garden. But now that I’ve seen some mature, uh, some of the flowering plants mature, I know that they’re going to be transferred to a pollinator garden that I have ready for them on the other side of the yard.

I don’t want to crowd any of these plants and I do not want to have to prune any of the natives. That is just against my whatever, and it’s a lot of work, so that’s good, Right place, right plant. Right places really will go strong once they start to mature.

[0:25:30] Erin: Well, another factor is um, with, like the needing to prune. Um, isn’t it true? You don’t necessarily want to get down into the rain garden because it’ll compact the soil and affect the infiltration.

[0:25:44] Valorie Savisky: That’s exactly right. So I am a real advocate of healthy soil principles and that’s what creates this bio-diverse ecosystem. I have a lot of um, I’ve built an environment to attract a lot of microorganisms into my soil, and compaction really destroys the soil construction and the air spaces and the places they live in, the soil. The more air and space you have, the more water it will hold in, the more in combination with the soil health and the plant roots are what take out the toxins from the runoff. So plants are key. I didn’t know this before I became a Master Gardener, so I’m so happy I don’t have to use fertilizer. I want to attract bugs and insects and birds and whatever.

So birds live on moth larvae and I really have hated that because they usually chew the plants up. But if you have enough and being an organic gardener, you have to have a tolerance for your plants being chewed on a little bit. So I you know I’ve already seen more bird, more types of birds, in my yard and I had hummingbirds right away as soon as the Mahonia uh started to blossom, and then I had Asters come in August and September, so they were the big pollinator attractors. I have done a lot of studying on what plants are the best pollinator attractors and Asters, California poppy, godetia, and um, there’s one other one I can’t quite remember, but I will definitely have all of those in my yard eventually. So I had nothing in this yard and I’m building it up to be an ecosystem.

Misconceptions About Rain Gardens

[0:28:16] Erin: Are there misconceptions about rain gardens and um?

[0:28:31] Valorie Savisky: yes.

[0:28:31] Erin: Yeah, just in general. What, what, what are some of the, what are some of the misconceptions about?

[0:28:38] Valorie Savisky: There is a main misconception that I discovered. So one of the biggest misconceptions that I discovered from a lot of visitors (and we had, what, 328 visitors to this garden) was the main question was about this depression in my ground retaining water. They, and everybody, a lot of people who were into water retention said “Why don’t you just have blue barrels, have your downspouts running into blue barrels?” I said, “That is not the purpose of a rain garden”. I got that question from many of our visitors and the other misconception was “Boy, I sure hope it doesn’t overflow when it rains a lot”, because it really rains hard in Elma during the winter.

And I knew I was not worried because I’d follow the instructions in the handbook to a T because I knew I was going to have a lot of scientifically based questions here. I followed the instructions to the letter. So that was not an issue. I don’t even have sitting water in it as much as it’s rained this winter so far and we’ve got, so that this time of year is a great time to do that, that filter, that drainage test, and then, after it dries out a little bit, you can. You can dig holes around your yard or keep digging holes to see how it drains out when it dries up a little bit. If it doesn’t drain within the prescribed amount of time, you seriously need to think about not building a rain garden in that particular area. So it’s all worked out beautifully, just as if I planned it scientifically, which I did.

[0:31:03] Erin: Yeah, I think a lot of people have this vision of the stormwater retention ponds that are in a lot of housing developments.

[0:31:13] Erin: And they may be confused with what a rain garden is or the purpose.

[0:31:18] Valorie Savisky: Yeah, Well, they do drain, but they’re, they’re not a rain garden. There’s a little bit of growth in the development. I lived in Poulsbo. We had three or four of them and those now are required by municipalities for residential construction areas that are big housing developments. So the great thing about being in a house is you can dig, you can build one of these yourself without, without much expense. You’re doing your community a favor, you’re doing the ecosystem a favor and you’re doing the water a favor. And as climate change advances, potable water is going to be I think it’s going to be an issue because a lot of our aquifers are drying up. So if we can recharge that groundwater, everybody can contribute to that.

[0:32:30] Erin: So this is just a thought I had. So in an urban area where you have a lot more impermeable surfaces, that is going to necessitate a larger garden, correct?

[0:32:45] Valorie Savisky: Well, it depends on what you have in your particular yard and what you choose to drain into the rain garden.

I think the most important thing is to run downspouts from your roof or, if you have a big cemented patio, to run some sort of drainage system in that, and usually large urban areas have stormwater drains.

So just go out to your sidewalk and clear off the drain so leaves don’t plug it up. But I think as individual homeowners we can all contribute and that was one of the things that King County did, was it really encouraged their residents to build rain gardens, and they gave a lot of seminars and were very helpful in that.

So Kitsap County does the same thing. In fact, I have a Master Gardener friend in Kitsap and Kitsap Conservation District excavated the area she wanted to use and it also hauled in the proper soil because she had a lot of clay. So they dug that out and they brought to her what she had to install the proper texture of soils that needed to be in the different layers of the rain garden, and so she’s a Master Gardener and a plant expert so she knew what she wanted to plant. But they were very helpful in keeping her encouraged and helping her in this process.

Other Benefits of Successful Rain Gardens

[0:34:36] Erin: So you talked a bit about one of the functions of a rain garden being to filter impurities from the water before it gets back into the water table. So what else, as far as like water conservation and those, what other type of efforts can benefit, or can rain gardens be of benefit?

[0:35:03] Valorie Savisky: I think, the fact that it slows the flow of runoff.

So if all of my neighbors had rain gardens, we would have very few puddles on the street. We don’t have sidewalks in my neighborhood but it substantially slows the flow of the runoff as it’s filtering through all the compost and plant roots.

So I think, relative to water conservation, if you have native plants, which I highly recommend, and the guide has an extremely huge appendix for all kinds of natives, they will be more adaptive to the climate.

So hopefully there’s not as much need for watering, except the first year, year and a half, two years to get the plants established, and then after that they should be pretty self-reliant, which also, if you have flowering plants and pollinator plants and plants that attract insects, like goldenrod for instance, I’ve had them in Ocean Shores and I watched all the different sorts of flying insects that land on that plant and they come out in August or September, so they’re a late bloomer.

I mean that’s a must to me in a pollinator garden or a rain garden because that attracts all kinds of little guys and it also provides and you’re also providing habitat if you don’t cut down for a plant that dies back on the first freeze, leave it up and that will provide seeds or food or habitat protection. For example, bees need water and a lot of them live in the ground, so you don’t want to be stomping around. I mean, and that’s good for soil health because you don’t want to compact your area.

[0:38:14] Valorie Savisky: I have a couple that might give someone an idea. Even though the plants are so teensy-weensy, I think the photo is good enough so you can get an idea of at least the shape and zones. Like I said before, my zone 2 is not very well planted because I just didn’t have the space in this yard, which you’ll also see. It’s 23 feet wide, this part of my yard is, and the sidewalk goes out from the house, so I’m exactly 10 feet. The rain garden starts exactly 10 feet from what would be the foundation of my house, which is exactly that’s the minimum that one wants relative to foundation, to rain garden to get the moisture away.

[0:39:40] Valorie Savisky: Well, I also want to plug the certification program that WSU Extension offers, which is a rain garden certification and it’s online only. It’s pretty affordable and it’s all self-study, and it walks you through the handbook and they’re, you know, open book exams on each section. So that’s where I got my good information on doing a rain garden.

Final Thoughts

[0:40:32] Erin: Okay, any final thoughts about rain gardens?

[0:40:37] Valorie Savisky: I just think it’s one of the one of the big questions or the big comments that came up during the the garden tour was I think people were so excited about this project because it’s something they could do themselves and and they I talked about all the resources that are available, so there’s no guesswork, and so I got a lot of really positive reactions. Even though there was only one person that said she would have rather seen a lot of flowering plants in the garden instead of my startup. But this project was put on the tour mainly for educational purposes and I think we met all of those educational purposes, so I was just really excited to have had that opportunity.

[0:41:34] Erin: All right, I think that about wraps it up, so thanks for joining me.

[0:41:39] Valorie Savisky: Thank you, Erin, for doing this. You’re an awesome Master Gardener, and I really value your friendship, so thank you so much.