Hi Kim! Nice analysis!

And you identified the source of the problem. Nice job.

I would say just "bite off what you can chew". If a large rain garden seems overwhelming, be comforted by the fact that they often over-perform. So start small, with what you feel is do-able, dig-able, and weed-able.

Then, if next year you think a bit bigger would make it function better, and stop more water from causing erosion and problems down the driveway and road, then make your rain garden bigger. Rinse and repeat until problem is solved. Then, once the problem is solved, you don't have to make it any bigger!

Is that encouraging?

Thank you, Susan! Yes, very encouraging! Smaller is probably better for me right now. So maybe only 12 feet instead of 30. :)

Off to perform a percolation test. I'm a bit behind the class right now as I was out of town 2 Fridays in a row, but am working hard this week to catch up. Will post my progress!

Percolation test result: 1 hour, 54 minutes.

Pretty quick! You are in the realm of sandy loam. You have a lot of flexibility on plants because of that infiltration rate. Also, this makes it even more hopeful that the garden will capture even more of the runoff water than anticipated.

A closer picture of my selected rain garden site. It's about 4.5 feet wide:

Here is my base plan (sorry, I'm really awful at the drawing, LOL) of my yard where the rain garden will go:

I'm a little worried that 4.5 feet is not wide enough for a rain garden?

Also, I'm making this garden less than half the size I should to handle the 840 sq. feet of runoff from the roof. I feel like 15x4.5 is about all I can deal with right now!

If you look closely, you can see up at the top of the driveway a circled area where I can build another one next year. I will probably connect them somehow, as the outlet (which I forgot to draw!) for the 2017 rain garden will be at the top of the garden. (Top being relative, as what is the top of the paper actually is east.) Overflow will probably still run down the driveway, which at this point can't be helped until next year. At least it will be *less* runoff going down the drive! Yay!

You can draw just fine! 4.5 feet wide is plenty wide enough for a rain garden, I've seen some that are just 2 feet wide. Since there will be so much water coming into the garden, I would choose some sturdy plants like blue flag iris and sedges to place at the 'bottom' of your garden (where the water comes in). Looking forward to seeing your planting design! -Catie

Thanks for your input, Catie! Much appreciated.

Some plants that I'm considering to incorporate into my rain garden design (sandy loam soil, part-shade). These may not all be available, so I'm keeping an open mind about options:

Black-Eyed Susan

Purple Coneflower

Blue Flag Iris

Blue False Indigo

Wild Geranium

Sensitive Fern

Cardinal Flower

Some kind of monarda (native)

Porcupine sedge

Design drawing coming soon. :)

OK, here is my plant plan. It took me about 3 hours to complete!

I forgot to label the blue plants in the center, which would be Blue Flag Iris.

Because this rain garden is on the small side, each square on the paper is equal to 6 inches.

I didn't really think through the placement of the Cardinal flowers and the Iris in relation to the inlet pipe. I may have to trade their spaces as I think the iris will hold up better under a deluge.

I'm ok with this looking a bit like a circus as far as color is concerned; I like circuses!

I think I did ok with the berm border. I wanted color all summer, and I wanted something shrubby near the deck (lead plant!)

This is right next to the main entrance of my home. I want it to look more happy than functional, without taking away any of the actual function.

Also, I totally forgot that I have lots of purple coneflower, which I intend to use. I'll likely cut down on the monarda and use the coneflower in it's stead.

Nice design! I think it will look like a native prairie with all those colors, and more random placement. I agree though that the iris would probably do better at the inlet. My only question is if there is a gap on the side of the rain garden adjacent to the concrete curb (at the bottom edge)? It looks like you left 6". I would recommend planting strawberry or something there so that there isn't any space for weeds to grow. I would leave it the same level it currently is so you don't expose too much of the curb or have water sitting right against it. The coneflower will be perfect!

I'm a native gardener, so yes, this is how I like to see things. :)

You are correct that I left 6". I was undecided as to how to handle that; I didn't want the berm right against the walkway. But something low there would be better (and easier!) than the grass that is currently there.

Thanks for your help! :)

Sounds like a great plan! Best of luck digging and planting! :)

And a month later, I'm back with an update and questions. :)

Finally located most of my needed plants a couple of weeks ago, and then it took almost 2 weeks to do all the digging.

Here is my husband working on the digging, with some help from my cat, lol:

Here it is leveled and ready for planting:

The inlet freshly installed, but not yet buried:

And here it is mostly planted, with some empty spaces left for the plants I have yet to acquire (and the edging for that top portion):

Which brings me to my questions. :)

1. If you look closely, you can see at the bottom of the most recent photo the edge of the concrete walk. The berm pretty much starts right at the walk, which I did not plan but it seemed like it needed to happen that way because that edge of the garden is about 3 inches lower than the top edge. (Top of the photo.) I felt like it needed that extra reinforcement, instead of leaving the 6" flat at the edge. You can see the blue eyed grass I have planted there, BUT...I think I need more? It seems like if it rained really hard right now the edge of the berm would start to erode away.

2. Take a look at this photo, I tried to take it so you could closely see the inside of the berm:

(I just noticed the photobombing golfball in there, lol...I don't even know, lol)

So the depth of the berm is about 8-9". I'm worried that the whole thing is going to erode *down into the bottom* even with the mulch on it. So my question is this: Can I mulch this with leaves instead of something more chunky, like woodchips? I'm thinking the leaves, if I water them down after placing them, will hold things in place better. Should I plant more in the sides of the berm? Thoughts?

Thank for any and all ideas. :)

Hi Kim. Nicely documented! I can see what you are talking about.

Well, you see it in person, so follow your instincts. You would be surprised at how mulch stops erosion, but it does have its limits. In that one spot, you could put a line, or a few, rocks. Whatever size you like, anything larger than fist size should do it.

I don't have an opinion on shredded wood vs leaves. I use leaves in my garden, but most people use shredded wood. They would probably both work.

Anywhere there is concentrated water, like where it comes out of the pipe, often you need a few rocks to "armour" the ground right there, so it doesn't erode. There may be other places, and you can strategically put rocks where it seems to need it.

So, do you have a few rocks around?

Hi Susan, Yes! I have TONS of rocks. I will most definitely be able to edge with large rock, and immediately. I still may put in more blue eyed grass, we'll see how it goes.

Any thoughts on the inside of the berm needing more plants? Or do you think the mulch will do the trick?

Thanks for your input! :)

A photo of the inlet (left) and outlet (right).

After 3 months of planning and hard work, my rain garden is complete!

Here are the last plants (southern blue flag iris) as they looked after I pushed aside the leaf mulch to insert them, last Friday:

I had incorporated the rain garden into the deck build off the back of the house, so the whole thing needed to be done at the same time. Thus, here we are 3 months later. :)

We had a LOT of rain today! Here it is in a still photo, filling up:

And a short video of it in action:

Thanks to Susan Bryan of Washtenaw County Water Resources Commission, and Jamie McCarthy of the Kalamazoo Valley Watershed Council. :)

Awesome Kim!!! Love the video!