Tuesday, November 17, 2009

Building a Rain Garden the right way!

It sounds like a bit of a rant.

Well it is. Not being mean, and trying to not be rude, but I feel that I need to do this.

I saw a post about building a rain garden. Someone used a magazine article, which actually was a good article, and they did attribute and thank the magazine for letting them use their info and picture. But they inserted their words into the article, and gave advice that was incorrect, IMHO.

I am a Certified Rain Water Harvesting Specialist in Texas, having had training that is available above and beyond normal training through the Master Gardener program. Rainwater harvesting is a big deal down here, especially with the droughts we have experienced lately.

It may well be that you can do this and this and that, and install all sorts of extra rocks, gravel, soil, and whatever else. But it certainly isn't necessary, nor even desirable. Common sense is common sense.

The purpose of a Rain Garden is to manage storm water that rushes off impervious surfaces; the roof of your house, sheds, or even the road or a sidewalk. The water rushes to the storm drains, into streams, rivers and lakes, and carries many pollutants and chemicals with it, AND our precious water is gone too! What the Rain Garden does is trap the water and allow it to seep through the soil, cleansing the water and allowing it to percolate back to the aqua systems.

The Rain Garden is NOT a treatment for the wet spot in your yard! To put it there defeats the purpose of the Rain Garden; If the area doesn't drain well, it isn't going to do a bit better just because you planted a garden there. It doesn't drain for a reason; clay soil comes to mind, or heavy equipment could have been stored or parked there for a long time. Building a rain garden is work, and there are much simpler fixes for that wet spot than putting in a rain garden. Fix that low spot, either by filling or by installing drains! A Rain Garden installed in that 'wet spot' in your yard could easily become a fantastic breeding ground for mosquitoes.

A Rain Garden is a man made depression in the ground. We have clay soil here, so this rain garden is pretty shallow. The garden is 10' wide x 52' long x 12" deep. But that size and that depth, creates a garden that handles the water off this building and drains in 24 hours. If we had sandy soil that drained faster, we would have dug it out to at least 18", but not ever much deeper.You can get a good idea of the layout of our rain garden. The garden should be at least 10' away from the building. That is important. The water comes off the building very fast, down the downspouts (2 of them), and runs the 'river'. That's what the kids call it. We didn't use anything except some landscape fabric to keep our rocks and gravel from disappearing into the soil in the river bed, and we didn't dig the river bed out. We did build embankments of a few inches and really pounded them solid, so they wouldn't wash away. Lay the fabric and the rocks and gravel. The water runs under the little bridge. We dug out under the bridge so that water would fall fast enough to not be dammed at the bridge. The garden basin is dug to 12", and the soil taken from the basin is used to build a berm on the outside edge. This berm will help to hold the water, so it can trickle through the ground below. Pile soil around the basin, and whack it with the back of a shovel, then stomp it until it is very solid. You want it really compacted.
We mulched the rain garden with hardwood mulch, and planted many of the plants that grow wild in our ditches and pastures. We planted buffalo grass on our berm, but you don't have to. You can use that area to plant flowers, ornamental grass and small shrubs and trees. We are now removing patches of grass to plant flowers; drifts of black eyed Susan, coneflowers, Blackfoot daisy, native clematis, rock rose.....

A word about mulch; Do use hardwood mulch, so it won't float away, and it won't deteriorate quickly. Don't use pine, you will just wind up with a mess.

We set out to put in a Native Plant Garden, and were confronted with this rain water, rushing from the downspouts, and eroding the ground at the building; thus the Rain Garden was incorporated. This garden has grown a LOT! Kids are always in here, they love that bridge. We have birds and butterflies galore. We had so many butterflies last year that a woman was seen 'stealing' our caterpillars! Grrrrr.....

A Rain Garden doesn't have to be this size or shape, and you don't have to plant natives in it. You can plant anything you want, just be sure that what you do plant doesn't mind having wet feet every once in awhile.

26 comments:

azplantlady said...

Hi Janie,

What wonderful information! Living in a dry climate, water is such a precious resource that we strive to conserve, usually by teaching proper irrigation techniques and schedules as well as using native plants. I hope many people are inspired to create the proper rain garden.

LeSan said...

Well there you go again, teaching me something new. I am becoming hard pressed to maintain my ignorance with posts like this. I do have a few wet spots to contend with. I haven't done anything with them yet but I had in mind what I now know is innacurate information. I think I may just go with the "fill it up" method. Thank you Janie for another great post.

Corner Gardener Sue said...

Hi Janie,
It looks like I don't have room for a rain garden. I had thought about trying one, but wasn't sure if we had a good place for one. We use rain barrels, so that may mean we couldn't have a rain garden, anyway.

Elephant's Eye said...

We have a 'rain garden'. I call them apple creek and plum creek. Glad to be reassured that they don't have to be deep. And we have rain barrels to catch some, for plants that are thirsty next week ...

Jim Groble said...

Nice path. We have started a "rain garden" where we planted swamp mallo and marsh milkweed. both of these plants are native to Ohio, are relative prolific, and the garden club called them weeds. They attract butterflies, bees and of course rabbits. The area collects water during every rain.

Tom - 7th Street Cottage said...

Great information, but who the heck steals caterpillars? I mean, come on!

I've got a gully which used to be a creek. It's lined with native stone. The runoff from the street is funneled down the gully when it rains hard. It was here when I bought the place. I've never seen it flood. Water always tends to stay within the embankments and finds its way into the ground.

The Violet Fern said...

I LOVE this garden ... I have always wanted a "dry creek bed." Since you are an authority on rain gardens, is this term synonymous with a rain garden? If not, what is the difference? I cannot believe a woman stole your caterpillars! The nerve!

janie said...

Well, you would have to know the caterpillar lady. She is a little different. She had our little cats on her arms, and her front, and on her neck. Kids were having a fit, telling her that it was harmful to the cats to come into contact with the oils of our skin. It was a riot!

All true, I promise.

Sue, you don't have to have a large area for a rain garden. You could put one in an area that is 4'x8'. You could add to your corner garden, include a rain garden. They are great. Google 'rain gardens', and see what you come up with. I know you will be impressed.

BTW, there are a LOT of rain gardens in Wisconsin especially. Some are just beautiful.

I remember Tom's gully. We talked about a rain garden there before.

VF, a 'dry creek bed' is closer to the 'river' in my picture. They are not the easiest part of a landscape to keep looking nice. Weeding one is not fun, as the rocks make your fingers sore. And weeds will for sure grow there!

Thanks for the nice comments, everybody!

Wendy said...

This is really nice!

Well, I must admit, I was going to plant a "rain garden" in my low area that gets swampy. Guess it wouldn't have been the right thing to do. Mind if I ask a question? If I have an area that gets flooded every time it rains (and is already planted with lots of stuff - and obviously lots of stuff has not survived), what should I do? Just add fill dirt or compost or something like you mention? Would this just get washed away? I can envision dirt just sort of floating to one area. ho hum. I'm so frustrated with this area. It's basically the entire length of my side yard.

James Missier said...

Never heard about Rain Garden. Thanks for the information - will look into it & see what I can learn from it.

janie said...

Wendy, What does the water do when that area gets flooded? Does it drain into the ground, run off slowly, or eventually just dry up? Is it there for an extended time? Does it just sit there, is what I am wondering.

Mosquitos hatch in 4 days. You don't even want them to be laying eggs, so you want something to happen so that water goes away in about 24 hours.

If the water does drain, trickles through the ground, then I would do the work to make it a proper rain garden. Do some digging, make a berm, level the floor. Then choose your plants with the idea that they will sit in water for brief periods, and will not resent that.

If the water just sits there, then I would be putting in some drains. You can visit any of the box stores, and find a whole world of PVC products to help you do this. You can put in French drains. You can visit the library or the internet to find out how to do this. It is not so much work as you might think.

Just be sure you set the drain cap below the ground a little, so water can run in there. We looked at an area that didn't drain, even after they had put in multiple drains. Looking at the caps, I could see why. Every cap was sitting above ground about 2", so the whole town would have to flood before any water could get into her drain. Plantings can/will hide your drains, so you will never know they are there, but they will help so much!

Good Luck!

janie said...

James, I never thought about it before, but what kind of soil do you have, anyway? I bet it is beautiful!

Amy said...

I enjoyed your post, Janie. Good information to know...We do have a spot where all the water goes in our yard :/ It is a mess. Thanks for your post. -Amy

Christine said...

I guess if we called it storm water runoff management, it wouldn't get that much attention! It is amazing, though how these sustainable concepts can get convoluted. Thanks for setting us straight!

Mary Delle said...

Great post!! You should write a book on this as most people don't have the slightest idea and believe the article you mentioned in the beginning of your post.

Wendy said...

Thanks Janie!! THis is really helpful. The water I have does eventually drain. Probably within 24 hours or so. The winter snow melts make a great big muddy mess though. I do have a LOT of mosquitoes, but not sure if it's because of this. I may look into a proper rain garden then! Thanks!!

Thomas said...

I'm ashamed to say that this is all new to me...Rain garden? I'll have to do my research. It seems like such a great way to conserve.

Randy Emmitt said...

Janie,
I recently read a book on rain gardening and you summed it up pretty good. They however always mentioned putting in sedges as sedges to very well and absorb up bad chemicals and such.

Tatyana@MySecretGarden said...

Great post, educative and helpful! I am working on out wet spot behind the house, and will use your information for sure!

greenlifeinsocal said...

A rain garden sounds so much more attractive than ground water recharge system, but they serve the same purpose. Very informative post. And thanks for stopping by my southern California "plot." --Lou

janie said...
This comment has been removed by the author.
janie said...

Randy, I have never seen a list of 'the preferred plants for a rain garden' or anything about planting sedges in rain gardens, but I know that nutgrass will grow very well in a rain garden. And nutgrass is a sedge.

Nutgrass is the bane of my existance! LOL

"Rain Garden" does have a kind of romantic ring to it....

Sylvana said...

I was part of a project in our area a few years ago that funded homeowners to put in rain gardens. I planned and built it myself, and I love it! Unfortunately, it is difficult to get a good picture of it I also have rain barrels to collect rain of the parts of the roof that do not drain into the rain garden.

janie said...

I have rain barrels and an old cistern to save rain water. I just think we should use what is given to us, save it and not squander our gifts. Plants love rain water. It has perfect ph!

I really don't know which I find more interesting about our project- The native plants, or the rain garden. Both are very interesting to me!

Jacqueline said...

A very interesting and insightful post. Thanks for sharing, Janie.

Jess said...

Super beautiful garden. I agree that dry creekbeds are a bit of a pain to weed, and I find it hard to not let mine disappear under debris, but I do love it. I built it last fall, near a downspout, but I didn't expect it to function as a river! I thought that because I didn't put plastic under it, the water would seep into the ground rather that flow down the river, but to my dismay, I saw that river was directing water quite efficiently right onto the sidewalk. I therefore rebuilt it and gave it a little meander in the opposite direction, so it now terminates in the soil--sort of created a bit of a rain garden without knowing what it was called, I guess. Thanks for this fascinating post, I'm bookmarking your blog. :-)