Part II - From Mud Pit to Rain Garden

By Linda Mills, River Hero Homeowner

In the photo below, it may look as if we could aerate the ground and plant grass seed in this section of the yard, right? Tried that. It washed away. Plant some perennials, soak up the water? Tried that. Rotted. Bulbs? Rotted. Shrubs? Slow sad death.

The problem was that runoff from the roof flowed into this lower area of packed clay. Enough rain and it would flow out into the street. Just a little rain and the water would stand. And stand. As you can see the weeds were happy, but I still wore rubber boots into that part of the yard.

Luckily, a rain garden was one of the projects approved by Alliance for the Chesapeake Bay based on our runoff audit. I must admit, I was a little skeptical at first. I understood the concept of a rain garden—a depression in the ground planted with native plants that didn’t mind damp feet. The plants and the depression would allow rainwater flowing from our roof over our compacted yard to be absorbed. A rain garden would also reduce runoff by allowing the water to soak into the ground as opposed to flowing into storm drains and, in our case, Reedy Creek. It was the perfect solution to our problem if it worked.

           

As soon as the Greener Landscapes team arrived with the backhoe, I knew why our attempts had failed. The first thing they did was dig a hole…a large, deep hole as you can see. 

Shortly after they finished digging that hole, it rained. The water didn’t drain much. I was a little worried, but everyone assured me that all would be well (or dry as the case may be) in the end.

The next day the Greener Landscapes team brought in a bio-retention mix. It was made up of 50 percent coarse sand, 25 percent topsoil, and 25 percent compost. Ian Johnson of Greener Landscapes says on other projects, “We have used up to 66 percent sand with 16.5 percent topsoil and 16.5 percent compost. Visually a pie chart divided into three, where two slices are sand and the last slice is divided into two, one half topsoil and the other compost.” It all depends on the situation. Our rain garden holds between seven and ten cubic yards of bio-retention soil. The dirt that was dug out originally was used to build a berm around the rain garden, as well as berms for the upcoming BayScape. Clever.

The native plants went in next. The landscaping team knew to consider that the rain garden would have various zones where different kinds of plants would thrive. For example, the center and the deepest part of the garden would support the wet-loving plants. That’s where they planted the Virginia blueflag iris. These plants have long-lasting purplish-blue flowers that attract humming birds and insects, and roots that hold the soil.

           

On the slope, the team planted Chrysogonum (common name Green and gold) and foamflower—both flowering groundcovers. Closer to the rim where it’s a little drier, the shrubs and tree went in. The American beautyberry is developing glorious purple berries right now that the birds love. The fothergilla (which I had never heard of) will produce one of the first blooms to appear in the spring. Its white fragrant blossoms will attract insects and butterflies.

Finally, the American hornbeam, or ironwood, tree was planted. These trees love wet feet and do not grow very large so it is perfect for our rain garden. Birds eat its seeds and catkins. Of course all of these plants are adapted to our climate, and once established do not need extra water or fertilizer.

So the day the plants went in, it rained. A lot. The drainage was somewhat better, but there was still lots of mud. I was encouraged, but still wearing my rubber boots.

I should have had more faith! Ian Johnson and his team at Greener Landscapes knew exactly what they were doing. Once the berms were completely sculpted and the mulch was laid down, we had a gorgeous rain garden. The best part is it works! See the visual evidence in the photos below. And I can’t wait until next year to see these plants burst forth with blooms that attract wildlife. 

Completed rain garden during torrential rain.

Completed rain garden less than 10 minutes later. No runoff! And no worries!       

Next time: Part III—From Boring to BayScape!