Keep your rain garden clean and healthy with regular maintenance, just as you do all other areas of your landscape. Plan on including these maintenance tasks:
Regular watering. Water new plants about twice a week until they are established, about a year. After that, your garden needs about 1 inch of water a week, and especially during periods of drought.
Annual mulching. Mulch is an important component of your rain garden. It protects the plants, keeps the soil moist, reduces weed growth, and improves the infiltration of rainwater into the garden. Maintain a 2- to 3-inch layer of mulch—adding new mulch in fall or spring. Make sure mulch doesn’t collect in the basin, however, as this reduces ponding and the functioning of the garden. About every three years you may need to remove and replace old mulch.
Removing accumulated sediment. Rake back mulch and remove silt, debris, and eroded soil that washes into your rain garden—otherwise it can decrease infiltration and kill your plants. Clean away any sediment that has accumulated at the inflow point. Regularly remove fallen leaves, twigs, and dead vegetation. When mowing, avoid discharging grass clippings into the rain garden.
Pruning and weeding. Follow good pruning and deadheading practices for all shrubs and perennials to maintain a neat, well-managed appearance. Weed new gardens frequently to keep weeds from competing with plant growth—avoid using herbicides. An established rain garden needs less frequent weeding.
Skip fertilizing. Fertilizers are typically unnecessary. Your garden construction, soil amendment, mulch, and selection of native plants provide a solid foundation for a healthy rain garden.
Replanting. Over time, you may need to replant areas of the garden as sun, shade, and moisture levels change. If a plant isn’t doing well in one area, don’t hesitate to move it to a different location where it might have a better chance of thriving. Divide perennials when they overgrow their allotted space.
For addition information, see previous blogs in this series, Rain Gardens—Parts I, II, and III, for resources on building and planting.
Article written by Beth Leonard, Extension Master GardenerSM Volunteer.