Vetiver Rain Gardens

Rain gardens are becoming popular ways of biofiltering polluted rainfall runoff from gardens, community sites and so on. Rain gardens are especially useful where runoff ends up in streams or lakes, particularly if the lake is the source of community water supplies.  Most rain gardens use native plants. Vetiver grass should be considered for rain gardens in areas where it will grow throughout the year and survive the winter.  In the US this means California and the Gulf States. Most rain gardens comprise  plants grown in natural or man made depressions where runoff is channeled and the filtered.

Vetiver will do a far better job of cleaning up polluted run off than most other plants.  It will remove over 90% of nitrogen and phosphate from fertilizer in runoff, as well as heavy metals – remember the clean up of parking lot runoff in California?  The great thing about vetiver is that it grows well in standing water – therefore good for shallow water collectors.  Also it can be planted along the boundaries of  home lots – thus demarcating boundaries and at the same time acting as a biofilter, particular those located across the slope.  It, being a nice land scape plant,  can help hide/soften ugly fences when grown as a hedge.  It can also be used in its own right as a “green wall” to divide a garden and perhaps screen out unsightly objects such as garden sheds, compost heaps etc. You can even cut it once a year and use the leaves for mulch or compost.  The hedges provide wonderful habitat for wildlife and insects.  In drier areas it remains green and refreshing! On top of all this vetiver sequesters atmospheric carbon better than most plants and trees.

Paul Truong’s recent paper and presentation on design and modeling the vetiver requirements associated with effluent discharge should be helpful in designing your Vetiver Rain Garden.  So by developing a Vetiver Rain Garden you can significantly reduce polluted water leaving your property and benefit the planet by doing your bit in sequestering atmospheric carbon.

You will find a list of some of Vetiver grass suppliers on the TVNI website.

A Vetiver Rain Gardens could be great family project for both adults and kids! Why not try out the suggestion?

Dick Grimshaw