RAINWISE

Rain Garden Maintenance

Welcome to the rain garden maintenance page. Here you will find a detailed guide on how to maintain your rain garden. Download our Maintenance Guide in English, Spanish, Vietnamese, Traditional Chinese, or Cambodian.

 

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Rain Garden Maintenance Video

In addition to the guides, you can learn more about maintaining your rain garden with our rain garden care video. This video is also available in Spanish and  Vietnamese.

Weeding

Weeds can choke young plants and spread quickly. Pull weeds by hand or with a long- handled weed puller. Weed as necessary year-round, especially in late winter, spring, and early fall when the soil is still moist. Pull the entire weed–roots and all—so that it doesn’t immediately grow back. Never use herbicides/pesticides in your rain garden. Also, be sure to clean any sediment, debris, or trash from the inlets and outlets of your rain garden. If you need more help identifying a weed, the King County Noxious Weed page is a great resource.

a metal tool poking into the grass near a weed.

Weeds to Remove

1. Himalayan Blackberry: a light pink flower with wide green leaves. Photo caption: Vine with thorns and black summer fruit. 2. Dandelion: fluffy spherical flower or a small yellow flower with many petals. Its leaves are skinny and jagged. Photo caption: Long, deep roots. 3. Bindweed (Morning glory): Wide green lead that tapers to a point. Photo Caption: White flowers in spring to summer. 4. Buttercup: Small yellow flowers with 5 petals. Leaves with three lobes. Photo caption: Shiny yellow flowers. Spreads aggressively in moist areas. 5. English Ivy: a vine with green leaves that have 3-5 points. Photo caption: Vine with fast growth. 6. Common Vetch. Thin stemmed plant with hot pink small flowers. Photo Caption: Lots of seeds in pods after flowering. 7. Herb Robert (Stinky Bob): A vine with red stems, green leaves, and white flowers. Photo caption: Smelly weed with long, extensive roots. 8. Bittercress/Shotweed: A cluster of stems with alternating leaves going up the stem. Photo caption: Seeds pop off at slightest touch. 9. Grass: blades of green grass. Photo caption: Grass from surrounding lawn can spread into your garden and become the worst weed.

Mulching

Mulch (such as compost, leaves, and wood chips) prevents weeds, conserves water and protects roots. Check and maintain a mulch layer to a depth of 3 inches as necessary. The best mulch in a rain garden is arborist wood chips, available free from tree services. Look for any areas of exposed soil and cover them with mulch when needed. Be careful to avoid piling mulch up against plant stems.

A shovel picking up woody mulch. Photo caption: Mulch: Put mulch, such as wood chips, on the coil's surface.

Watering

Young plants need water to grow strong roots. Watering is important during the first two to three summers after your rain garden has been installed. In general, water when the weather is dry and warm, from May through September. Watering before 8am is best to reduce evaporation.

Be sure to water deeply, moistening the top 6-12 inches of soil. After watering, wait an hour, then dig down to see if the water has gone deep enough.

You can use a watering wand, oscillating sprinkler, or save time by laying out a soaker hose next to your plants and covering it with mulch. Learn more about how to water new plants and how to use a soaker hose.

A table describing the watering frequency of a garden depending on the age. Column heading 1: Age of Garden Column heading 2: Watering Frequency. Row 1: First year, every 3-4 days. Row 2: Second year, once every 2 weeks Row 3: Third year, once a month or more frequently depending on whether the leaves are showing stress (excessive wilting, browning)
a watering hose showering water on a garden. Photo caption: Water deeply.

Planting

If you need to remove dead or dying plants, replace them in the fall. This will give the plants time to grow more roots before the dry season. More extensive roots help plants fight off disease, dry summers, and cold winters.

The following are plant suggestions and plans which may be useful if you need to replace a rain garden plant:

hands holding a small plant. Photo caption: Plant: Fall is the best time to replace plants.

Download our Rain Garden Maintenance guide in English, Spanish, Vietnamese, Traditional Chinese, or Cambodian.

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