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By The Marsh Hen

The other day, while flying over Tallahassee, the Marsh Hen overhead some folks talking about creating a “rain garden.” From the sound of it, these folks were pretty sure they had stumbled on a new idea. Here were humans discussing the advantages of directing rain water from the roofs of their homes to a place on the ground which was deep enough to let the water seep into the ground over a period of days. They were excited about planting some of the same plants in their yard that they find in the swamp. They were talking about how a garden like this would solve two problems in their yards; first was how to use all the rain that runs off the roof, down the street and into the sewer. Second was how to bring some of those beautiful swamp/bog plants home to enjoy on those days when they could not get out on the water.

The Marsh Hen flew back to her lily pad home on the Wacissa River and casually typed in “rain garden” on her computer. Up jumped page after page of rain/bog garden sites. Upon closer examination, she realized they were from all over the U.S. and Canada. Gosh, this wasn’t a new idea at all.
However, it seems to be coming back in use again so she thought she’d entice other folks who might not have heard of rain gardens to try it.

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Regardless of where you live, some essentials of rain gardens remain the same: It’s best to locate the garden no more than 30 feet from the house in order to get the most benefit from the water that drains off the roof. In addition, the more sunshine that falls on the area, the better.

There were all sorts of formula to determine the square footage of the roof that will drain into the rain garden, the slope of the yard and the depth required to accommodate 100% of the rain the falls from the roof. The Marsh Hen almost gave up – until she read the fine print that said “ The rain garden may be almost any size, but the optimum size is somewhere between 100 and 300 sq. feet.”

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The most important requirement is that it’s level, which, for most of us means part of the area will be dug up and transferred to another portion of the new garden in order to create a level surface. If there is too much difference between the “top” and “bottom” of the garden, water will either run right off the land and never have time to percolate into the ground and water the garden’s plants, or it will pool and sit long enough to become a mosquito breeding ground. Even up there in Canada, mosquitoes are a problem. (In fact, the Marsh Hen and the Marsh Rider once went cross country skiing in below-zero weather in the Canadian Rockies and were impressed, but not surprised, to find large mosquitoes alive and sitting lightly in the snow on what we knew was a river bank in the summer.)

There are formulas for determining how deep the garden should be – but once again the fine print says the garden should be between 5 and 8 inches deep.

The length of the garden should be around 15 feet and the width should be in the neighborhood of 10 feet. The long side of the garden should face “uphill”.


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At this point, you are getting close to the “fun” part – laying out the shape of the garden, digging it and searching for suitable plants.

Use a garden hose to lay out the general shape of the garden. Be prepared to create a “berm” on three sides of the garden which will help keep the water inside the garden. Most, if not all of you, learned how to do this when you were younger and built small “dams” in the street gutters or in the yard to catch rain water. Then you used sticks and whatever else was handy – now you will want to use sod or a quick growing vine on the berm. Just make sure that vine is not an invasive species like old world fern or kudzu.

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When you get to this point, you may want to consider adding a small pond and/or a re-circulating water feature like a fountain.

When looking for plants in the wild, be careful about where you are and what you are bringing home. The Marsh Hen reminds her readers that Wildlife Management Areas generally have a “do not remove plants” regulation. So check before you pull.

Also, check to see if the plant is an “invasive/exotic” or native plant. Because you will keep a watchful eye over your garden, it may seem o.k. to include something like that beautiful purple loosestrife – but remember seeds get dispersed way away from the garden so do some research before selecting your plants.

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As you choose your plants, it’s also important to consider the height and texture of the plants. Put in several plants of the same variety and try to have plants which bloom in various seasons close to one another so there is always color in various parts of the garden.

The Marsh Hen has learned that plants which will sit in full or almost full sun and be on the “outside” of the rain garden or in an area which will dry quickly, should be “low growing” rather than tall. This is because the taller a plant’s stems, the more water it requires to bloom and grow.

The Marsh Hen thought the garden would be complete in time for this edition - but we have had so much rain it’s been hard to get out and dig the garden. She’ll have to show you pictures of the garden next time.
She can tell you it will have a circulating fountain and small pond for the dogs and birds and lots of marsh plants including these two.

Photo this page: White flowers are wild Queen Anne’s lace, Cycle of rain from roof and depth of garden (City of Tallahassee brochure) runoff from roof keeps this area moist, the garden being dug, photo by Marsh Hen), Passion vine flower, photo by Frank Vincentz; and swamp sunflower found in ditches, bogs, blooms all summer and fall, photo by Thomas Barnes, University of Kentucky.

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