How to create a North Fork rain garden

Credit: Monique Singh-Roy

The rain garden outside the Cornell Cooperative Extension of Suffolk County office in Riverhead. (Credit:Cornell Cooperative Extension courtesy photo)

How many of us have gone outside after a rain shower to check on our garden? Did it get enough water? Does it need extra watering after several days without rain? Is it a lost cause without a little help from Miracle-Gro?

The desire for a beautiful garden is widespread, but these days more people are choosing to garden with a conscience, a task that involves less fertilizers and pesticides and more native plants.

That’s according to Robin Simmen, a community horticulture specialist at Cornell Cooperative Extension of Suffolk County in Riverhead.

“That’s the kind of gardening that people want to do,” she said. “More and more we’re seeing nationally that people have had a rise in consciousness about what they’re doing out there in the garden and want to be part of the solution, not part of the pollution.”

Simmen believes one way to help the environment is by building a rain garden. A basic rain garden can be described as a shallow depression that has been designated to collect rainwater when it falls, quickly absorb it into the ground and support a plant community.

In other words, it’s a low-maintenance garden that pretty much cares for itself and doesn’t harm the environment.

Simmen is such an advocate of rain gardens that she regularly gives lectures on the topic. One Friday night workshop drew about two dozen people to the Peconic Lane Community Center in Peconic.

Participants expressed worry over the way their properties are affect the environment, particularly in light of the recent mass fish kills, which have been attributed to excess nitrogen levels in our waterways from excess fertilizer.

“I have too much lawn,” said Anne Surchin of Southold. “I’m very concerned about planting the sort of things that are good for the environment and I’m very concerned with what’s happening on the East End and the nitrogen running into the bays.”

Simmen believes rain gardens are perfect for Long Island’s maritime climate. First, they don’t require watering because they contain native plants that can handle too much or too little rain.

“They’ve evolved for the exact amount of precipitation that falls in that area,” she said.

And a rain garden doesn’t need fertilizers or pesticides.

“If you think of a natural landscape, those places are not getting fertilized,” said Simmen. “They are absorbing the breakdown of plants around them that contribute to the organic matter in the soil that provides all the nutrients the plants need.”

The rain garden at Downs Farm preserve in Cutchogue. (Credit: Monique Singh-Roy)

The rain garden at Downs Farm preserve in Cutchogue. (Credit: Monique Singh-Roy)

They also clean the water before it enters our water system.

“It’s completely natural and cleans the water that moves through it, so it actually removes pollutants from the water before trickling down into our aquifers,” she said.

To see a local public rain garden, head to Downs Farm Preserve in Cutchogue, where Group for the East End built one last year.

“Once the area was turned over, the entire process took just a couple of hours,” said environmental educator Missy Weiss. “The plants were planted by myself and several Girl Scouts. The native plants were purchased from a local wholesale nursery and cost about $300. The mulch was another $50.”

Weiss urges local homeowners to consider installing a rain garden.

“They assist in reducing flooding and also provide critical habitats for birds, butterflies and beneficial insects,” she said. “If a resident has the appropriate landscape to plant a rain garden on their property, there are so many benefits not only for the homeowner, but also the larger community.”

Native plants, no fertilizers or pesticides, cleaner water, and benefits to insects, wildlife and the community. Sounds like a win-win situation all around. So why are there still so many artificially green, landscaped lawns on the East End?

Simmen said it’s a cultural concept that will take education to overcome.

“We did not have lawns in the United States until the late 19th century,” she said. “The concept of the yard being decorative came from the popularity of big, green cemeteries like Greenwood Cemetery in Brooklyn. Those were some of the first public green areas in the country. The whole family would go to the cemetery to have a picnic while visiting a departed relative. That’s really where the popular idea of lawns in the United States comes from.”

But the only place green lawns are natural are in the British Isles, which receives an inordinate amount of annual rainfall, Simmen said. The problem likely began when people from those countries came to the U.S. and tried to recreate the environment.

“Think how challenging it is to grow lawns here,” she said. “That’s why this huge industry has grown around lawn care in the U.S., because it requires so much support in order to do it. It’s not in any way, shape or form a native form of vegetation in North America.”

Simmen would like locals, especially gardeners, to take a second look at what is and what could be growing on their properties.

“Think about all the birds and insects, think about how much we love our fruit. Understand that food depends on a healthy community of pollinators,” she said. “If we only offer a barren landscape in terms of what will support all these insect and plant communities that we need, then we’re going to pay the consequences for that.

“I would invite them to lift up their soil and take a peek underneath and see what’s going on in that soil. How healthy is it? Then I’d like to ask them if they would they want to drink a glass of water that had trickled down through the soil on their lawn.”

TIPS FOR PLANTING A RAIN GARDEN*

1.  Rain gardens need to be built where water collects. Observe the rain runoff on your property. Good spots for rain gardens are near curbs and at the base of slopes. Does rain run across your gutters and downspouts? Consider redirecting this runoff to your rain garden.

2.  After evaluating the soil, conduct a percolation test by digging a hole about eight inches deep and eight inches wide and filling it with water. If the water takes more than 24 hours to soak in, it is not a good location for a rain garden. The water should soak in at a rate of one inch per hour.

3.  Decide the dimension of your garden. Typical rain gardens range from 100 to 300 square feet.

4.  Plant native species. They are adapted to local weather, require little or no fertilizer, are excellent food sources for pollinators and provide habitat for birds and butterflies. Once established, their roots increase the water-holding capacity of the soil and prevent erosion. Recommended native pants include butterfly weed, swamp milkweed, marsh marigold, giant sunflower, turtlehead, joe-pye weed and New York aster.

*Source: Robin Simmen, Community Horticulture Specialist at Cornell Cooperative Extension of Suffolk County

The Peconic Estuary Program offers financial rewards to residents who plant rain gardens on their properties. For more information visit peconicestuary.org.

For more information on gardening courses offered by Robin Simmen and Cornell Cooperative Extension of Suffolk County, please visit ccesuffolk.org/gardening.