Harvest More Rain in the Landscape with Rain Gardens
A rain garden is a garden which takes advantage of rainfall and stormwater runoff in its design and plant selection. Usually, it is a small garden which is designed to withstand the extremes of moisture and concentrations of nutrients, particularly Nitrogen and Phosphorus, that are found in stormwater runoff. rain gardens are sited ideally close to the source of the runoff and serve to slow the stormwater as it travels downhill, giving the stormwater more time to infiltrate and less opportunity to gain momentum and erosive power.
With a planted depression or a hole, a rain garden takes full advantage of scarce resources with the opportunity to be absorbed, integrated, and saved.
Design Considerations for Rain Gardens
Rain Gardens are best placed near the source of runoff although with enough margin so as to not cause damage to the foundation of the structure. Here are some other tips to consider when designing your rain garden:
- Avoid damage to roots and foundations, place gardens a minimum of 10’ away from any structure or shallow-rooted trees.
- Maintain a3:1 or 2% slope until you reach the “edge” of the 8-12” basin, to allow water to pool and percolate, preventing erosion.
- Keep it away from your septic system and drain field, rights of way, and underground utilities or service lines to avoid damage and contamination.
- Place in in full or partial sun, so as to ensure evaporation in the event of excess water pooling.
Benefits of Rain Gardens
There are many benefits to the installation of a rain garden on your property, including increasing your property value. Here are a few more to consider:
- Reduce the amount of polluted stormwater reaching our rivers
- Filter pollutants such as oil, fertilizers, salt, pesticides, metals and bacteria out of runoff
- Promote infiltration and recharge of the groundwater table
- Reduce local flooding potential
- Conserve water
- Create diverse habitat for birds and butterflies
- Reduce landscape maintenance in terms of time and money
- Increase property value
Ideal Plants for Home Rain Gardens
Plants with deep fibrous roots tend to have a competitive advantage in a rain garden and provide the most cleaning and filtration benefits to the environment. Typical rain gardens are populated with natives or native cultivars because those are most well adapted to a locality. Listed below are a few great examples for our region to help you get started:
Carextumilicola- Berkely Sedge
Juncus patens –Common Rush
Muhlenbergia – Deer Grass
Stipapulchra – Purple Needle Grass (California State Grass)
Solidagospathulata- California Goldenrod
Mimulusaurantiacus – Sticky Monkeyflower
Epilobiumcanum – California Fuchsia
Lupinusalbifrons – Silver Bush Lupine
Sambucusnigra– Blue Elderberry