TRUE BLUE Gardening

Plant Rain Gardens Near Driveways

Why do we need rain gardens?

Rain Gardens prevent toxins from polluting Torch Lake and entering our drinking water.

Over the past 60 years, the Torch Lake Watershed has changed from natural vegetation to residential development. Now, there are more than 4600 parcels in the watershed, 1600 parcels along the shoreline and more than 25 subdivisions on the ridge overlooking Torch Lake.

The amount of stormwater going directly into the lake is estimated to have doubled due to the increased number of paved driveways and the increased number of lawns growing to the water’s edge.

As hard surfaces (homes, paved driveways, field stone patios, etc.) increase in the watershed, less rainwater percolates through the soil and more polluted stormwater run-off flows directly into the streams and Torch Lake.

Torch Lake’s water quality is a reflection of these changes in the watershed.

With over 40 streams flowing into Torch Lake, development along the stream corridors has also increased. Studies show that stream corridors with more than 10% impervious surfaces can’t support trout or aquatic life.

Photo: Trish Narwold

Image: Maryland Department of Natural Resources

What is a Rain Garden?

A rain garden is a vegetated depression that traps polluted run-off from driveways and other hard surfaces.

Rain gardens have native plants with long roots, which stop toxic chemicals such as oil and gas from cars, coal-tar driveway sealants and heavy metals from entering the lake.

What are the benefits to you and our water?

  • Keeps toxins out of Torch Lake so they won’t harm fish and aquatic creatures
  • Keeps nutrients out of Torch Lake so algae don’t grow and change its turquoise color to green
  • Keeps sediment out of Torch Lake so it won’t harm fish and aquatic creatures
  • Increases rain water infiltration and groundwater recharging our drinking water
  • Keeps drinking water safe from toxins
  • Provides habitat for more native plants and wildlife. 

Image: The Nature Conservancy

What can you do?

Protect Torch Lake’s high water quality, one Rain Garden at a time.

Step 1. Determine the best location for your Rain Garden.

Draw a sketch of your property marking the perimeter drain and downspouts.

  • Situate it down slope from the perimeter drain outflow or downspouts
  • Keep a minimum 10 feet away from your home to protect your foundation
  • Don’t put it over a septic field
  • Locate in full or partial sun

Step 2. Determine Rain Garden size.

  • Calculate the area of the driveway
  • Multiply by a number related to the type of soil in the garden

20% for sandy soil
30-35% for loam
45-60% for clay

  • Use this area to estimate the Rain Garden size

These numbers are inflated to ensure the garden can hold as much water as needed.

Step 3. Create a Rain Garden design.

  • Often Rain Gardens are longer than they are wide and positioned perpendicular to the slope of yard
  • Lay out a hose to set the perimeter of your Rain Garden
  • Group plants in odd numbers

If your Rain Garden will be located with 50 feet of a stream or the lake, then you’ll need a permit from the Antrim County Soil Erosion Office in Bellaire.

Stop by the Antrim Conservation District office on Stover Road due east of Bellaire. Or call (231)  533-8363.

Step 4. Pick your plants based on the garden conditions.

  • Sunny or Shady
  • Dry or Damp Soil

Select Native Plants from this list.

Step 5. Make sure the area for the rain garden is safe for digging.

  • Call Miss Dig at 811 or 1-800-482-7171 to determine locations of underground gas lines, electrical lines, internet cables or sprinkler lines

Step 6. Remove turf grass and dig 4-8 inches deep.

  • Use soil to build berms

Step 7. Line with a layer of 2-4 inches of loose, small or pea gravel to speed up rainwater infiltration time.

Step 8. Add a mixture of sand, compost and peat moss to your soil.

  • Mix well and cover the gravel
  • A good soil mix for rain gardens is 50-60% sandy loam, 50-40% compost

Do not use topsoil. This is important to prevent compaction of soil.

Fill the prepared garden area with water to make sure it drains in the directions you want it and soaks into the soil within 24 hours.

Step 9. Install plants.

Step 10. Mulch to keep in moisture in and keep out weeds.

  • Use shredded bark, like red pine bark rather than wood chips
  • Apply the mulch about 2-3 inches deep

Care for Your Perennial Rain Garden

First Season:

  • Water daily first 4 weeks
  • Remove weeds
  • Replenish mulch
  • No need to fertilize or use herbicides or pesticides
  • Plants should push out weeds as they mature.

Seasonal Care: Spring

  • Keep the edges defined for a well-kept natural appearance
  • Prune and remove dead material
  • Remove any invasive species that have taken hold
  • Add another layer of mulch

Photo: Washtenaw County, Michigan

Find more Caring for Water ideas in TRUE BLUE Gardening

Don't just wish that Torch Lake will stay blue.
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