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Perennial Garden with Muhly Grass, Blonde Ambition Blue Grama Grass, Solidago, Agastache, and Salvia

Watershed Wise Gardening

As the American West is experiencing increasingly frequent droughts, we as individuals need to get creative on how we can manage our water use – especially in the garden. Water is the most valuable resource on our planet. And yet, many people tend to waste it, and not treat it with care. Gardening gives us a greater appreciation of water, and how we can use this precious resource more efficiently. In a watershed garden, you can make the most of the rain that does fall to grow a beautiful garden, while supporting pollinators and wildlife, as well as contributing to healthy streams, rivers, and bodies of water downstream.

What Is A Watershed?

The Environmental Protection Agency definition is “an area of land that drains to a common waterway, such as a stream, lake, estuary, wetland, aquifer, or even the ocean.” All of our homes and gardens are connected to larger bodies of water. We can all play a part in managing watersheds, which are essential to healthy ecosystems, supporting both wildlife and human life.

What Are The Benefits Of A Watershed Wise Garden?

Watershed wise gardening is an intentional way to manage the cycles of drought and precipitation. The goal of watershed wise gardening is to slow the flow of water runoff, so that we can Recapture, Retain, Filter, and Purify water.

As a result of planting a watershed garden, you can...

  • use rainfall water carefully and efficiently,
  • save water and money by irrigating less,
  • help prevent erosion and pollution,
  • preserve and improve the health of your soil,
  • support wildlife and pollinators, and
  • contribute to a healthy community.

What Is Runoff - And Why Is It A Problem?

Runoff happens when rainfall, precipitation, or snowmelt can’t be absorbed into the ground. Hard surfaces, such as roads, driveways, sidewalks, and buildings that cover more and more of the developed landscape, can’t absorb water. Excessively dry or compacted soil can become a hard surface as well: in areas where rain is rare, the soil compacts and loses elasticity, making it unable to absorb water quickly. Therefore, when rain falls or snow melts, it has to keep moving through the environment. 

Did you know that urban runoff is the number one source of water pollution?

When water moves through streets it picks up pollutants and waste, and when it moves areas that use fertilizers and pesticides, those toxins are picked up as well. Runoff can also move quickly, which then contributes to flooding and erosion, which is causing more and more damage as we see increasingly frequent and heavy storms. Unfiltered runoff can carry soil, waste, and pollution into bodies of water downstream – which can cause problems for wildlife.

Watershed Wise Gardening: Recapture, Retain, Filter & Purify

The Solution: Recapture & Retain, Filter & Purify

A 1000 square foot roof can catch over 600 gallons of water with just one inch of rainfall!

When you recapture and retain rainwater or snowmelt in your garden, you are giving it the chance to filter and purify through healthy soil, instead of picking up pollution on its way downstream. This recharges our aquifers, keeps our waterways clean, and contributes to healthy bodies of water downstream.

Recapture & Retain: Slow The Flower Of Water

To recapture and retain water, watershed wise gardens are planted in a swale, or a shallow depression about 6-8 inches deep. The goal is to create a wide, shallow area into which runoff water drains from a roof, driveway, or other hard surfaces. This will prevent runoff from flowing away too quickly. (Scroll down to see Tips For Planting A Watershed Garden In A Swale)

Filter & Purify: Build Healthy Living Soil

Healthy living soil is essential for filtering and purifying water.  It is the foundation for thriving, beautiful plants above ground, and in turn, the root systems of your plants help in the process of filtering runoff. Healthy soil can also help convert many toxins into forms that are digestible to plants. It's important to use all-natural soil builders such as Yum Yum Mix, worm castings, and organic compost to support the living organisms in your soil. Plus, healthy, humus-rich soil can hold its weight in water and retain it for longer.

Always avoid chemicals, pesticides, and herbicides, to preserve your soil health and keep your watershed clean.

We only offer soil amendments that we trust and use in our own gardens – to help establish your garden, shop our top picks for all-natural soil amendments.

Build Habitat: Choose Resilient Plants

Watershed wise gardens need a variety of resilient, deep-rooted plants that can tolerate both drought and wetter conditions, as well as salts that may accumulate in runoff. Above ground, beautiful resilient plants add curb appeal to your property, help support pollinators, and create habitat for wildlife.

Choosing the right plants is a great first step to healthy soil and an effective watershed garden.  We recommend native perennials including Asters, Milkweed (Asclepias), Goldenrod (Solidago), Coneflower, Echinacea, and native ornamental grasses. Our Watershed Wise Pre-Planned Garden is a great way to get started!

Our Watershed Wise Pre-Planned Garden

Let your enthusiasm for gardening benefit the earth. Designed for sunny sites, our Watershed Wise Garden features beautiful, easy-to-grow native perennials and grasses with deep root systems. Not only are they beautiful, but the flowers and grasses also provide food and habitat to support pollinators and wildlife. You can enjoy watching pollinators visiting flowers in bloom from early summer all the way to late fall. After flowers pass, seed heads and ornamental grasses provide visual interest through the winter season. This garden can be planted in your yard, in a median, or in a sidewalk garden.

Planted in a 6” deep swale, the large 10-foot x 10-foot pre-planned garden can retain up to 374 gallons of water!

Tips For Planting A Watershed Garden In A Swale

Good preparation before planting is an important step in building healthy soil. This will give you a head start on growing a resilient garden that effectively slows runoff and filters water. These tips are especially helpful if you have heavy clay soil or very dry, compacted soil.

  • Dig a garden bed 8 to 12 inches in depth. The size will depend on the number of plants. Our Pre-Planned Gardens include a garden map to make layout easy!
  • Be sure not to leave a vertical edge, but rather a gentle slope down to the bottom.
  • Consider the path of water as it flows from your roof, sidewalk, or driveway. You may want to use some of the soil from the swale and use it to mound up the edge to help retain water. Try not to build a mound that will block water from entering your garden swale.
  • Till or dig the bottom of the swale about 8 to 10 inches deep, to loosen the soil and make it easy for your plants roots to spread.
  • Mix in a combination of compost, Yum Yum Mix, and worm castings before planting.
    • Compost: we recommend 1/2 to 1 cubic yard of compost per 100 sq ft (typically a store-bought bag is about 1 cubic yard).
    • Yum Yum Mix: we recommend 4 lbs of Yum Yum Mike per 100 sq ft.
    • Worm Castings: mix 1 part worm castings to 2 parts soil when planting, or work 1/3 cup per plant into soil above roots in spring, early summer, and fall.

More Plants For Watershed Gardens