DIY rain garden
As the world faces the challenges of climate change, it is becoming increasingly important to adopt sustainable practices that mitigate its effects. One such eco-friendly solution gaining popularity is the creation of rain gardens. These beautiful and functional gardens not only enhance the aesthetic appeal of your yard but also serve as a natural way to manage stormwater runoff. In New Jersey, late May to August is ideal to begin a rain garden. You can make a positive impact on the environment while adding value to your property!
Image from City of Durham
1. Planning and Design: (Rutgers offers an excellent manual for planning)
a. Evaluate your site: Assess the topography, soil type, and existing drainage patterns in your yard. Identify areas where rainwater tends to accumulate or flow rapidly.
b. Determine garden size: Consider the amount of rainfall in your region and the size of your property. A rain garden should ideally be one-third the size of the impervious area (e.g., roof, driveway) that drains into it.
c. Select plant species: Choose native plants suitable for your climate, ensuring they can thrive in both wet and dry conditions. Native plants require minimal maintenance and provide habitat for local wildlife. Rutgers has an excellent list of New Jersey native rain garden plants. It includes: Blueberry, Arrowwood Viburnum, Swamp Milkweed, Blue Flag Iris, Pitcher Plant, Ladies Trusses Orchid, Greys/Palm/Tussock Sedge.
d. Determine the garden shape: Opt for a shallow depression or a series of basins to capture and retain rainwater, gradually allowing it to infiltrate into the ground.
The US Environmental Protection Agency has some excellent landscaping ideas for all areas of the US. If you want to see a rain garden in person, check out Rutgers Rain Garden resources.
Image from TAPintoNJ
2. Construction:
a. Mark the garden boundaries: Use stakes and string to outline the shape of the rain garden. Ensure the slope is gentle enough to allow water to flow into the garden but not so steep that it causes erosion.
b. Excavation and grading: Dig the depression according to the size and shape planned. Maintain a depth of 6 to 8 inches for optimal water storage. Use the excavated soil to create berms or mounds around the garden edges to enhance aesthetics and prevent runoff.
c. Amend the soil: Add organic matter like compost to improve the soil structure and enhance water absorption. This aids in proper drainage and prevents waterlogging.
d. Install an overflow outlet: To prevent flooding during heavy rainfall, install an overflow outlet like a perforated pipe or a swale (open channel) to direct excess water away from your home and foundation.
Above: Digging out the rain garden bed. Image from NJ Future.
3. Planting and Mulching:
a. Arrange plants strategically: Place taller plants in the center or rear of the garden, gradually transitioning to shorter plants toward the edges. This helps create a visually appealing landscape while maximizing water absorption.
b. Planting technique: Dig holes slightly larger than the root ball of each plant, ensuring proper spacing. Backfill with soil, gently firming it around the roots.
c. Mulching: Apply a layer of mulch around the plants to suppress weeds, retain moisture, and protect the roots. Wood chips, straw, or shredded bark are excellent choices.
Above: A rain garden by a downspout from New Jersey Agricultural Experiment Station
Above: Image from CLC Landscape Design
4. Maintenance:
a. Watering: Newly planted rain gardens require regular watering until the plants are established. This can take several weeks as the plants are adapted to nursery growing conditions. After that, they should be self-sufficient, relying on rainfall to meet their needs. In times of extended drought, supplemental watering may be necessary.
b. Weeding: Remove weeds as they appear to prevent competition for nutrients and water. Regular maintenance and mulching will minimize weed growth.
c. Pruning and division: Prune plants as needed to maintain their shape and remove any dead or diseased foliage. Periodically divide overcrowded plants to promote healthy growth.
d. Soil maintenance: Add compost or organic matter annually to replenish nutrients and maintain soil structure.
e. Monitoring: Keep an eye on the water level in the rain garden during heavy rainfall to ensure it drains properly. Address any erosion or pooling issues promptly.
The Native Plant Society of New Jersey has excellent information for further research.
