Raingarden Education

Raingardens & Native Landscapes

Successful Establishment & Maintenance

What is a RaingardenA raingarden is a shallow depression designed to capture and soak up stormwater runoff from hard-surface areas around your home or business. Raingardens prevent erosion and protect water quality.

Some other types of raingardens are:

• Detention basins – artificial ponds adjacent to rivers, streams, lakes and ponds to protect against flooding, erosion and hold water for short periods of time

• Infiltration basins – shallow artificial ponds used to infiltrate water and protect water quality in rivers, streams, lakes and ponds

• Infiltration swales – shallow channels adjacent to streets or residential areas, that collect and dispose stormwater runoff.

• Ephemeral ponds – natural or artificial temporary pools of water that provide habitat for some animals

• Sedge meadows – large natural or artificial wetland areas planted mostly with sedges and other native wildflowers . Sedge meadows infiltrate water and protect shorelines from erosion.

Benefits of Raingardens

• Stormwater Infiltration

• Create Natural Habitat

• Improve Aesthetics

• Easy to Maintain

• Environmental Education

Stormwater Infiltration

• What do native plants do?–Have extensive root

systems– Infiltrate water deep

into the soil– Trap pollutants–Hold soils together

Turf Grass Roots< 1 FT

Heath Aster9ft

Switchgrass 12Ft

DwarfBlazing Star

15Ft

Little Bluestem

6Ft

Compass Plant>15F

t

Native Root systems are deep and strong

Stormwater Infiltration

• How do native plants help?– Infiltration prevents run

off into lakes and streams– Prevents salt, pesticides

and chemicals being washed off into our precious water resources

– Protects integrity of the land by preventing erosion

– Creates a natural buffer for our lakes and streams

Create a Natural Habitat• Provide shelter to our pollinators

– Pollinators ensure growth of seeds, fruits and crops

– Pollinators contribute towards the food we eat

– Herbicides, insecticides etc. negatively impact native pollinators

– Native plants provide a natural, healthy habitat for pollinators to thrive

– Pollinators are dwindling due to loss of habitat

– Conservation is of highest importance

Butterflies• There are many native butterfly

species – Monarch, Karner Blue, Swallowtail, Skippers

• You can enjoy a variety of these colors in your own backyard

• Fun and education while protecting precious natural resources

• Milkweed and Liatris species are popular

• Look for the butterfly symbols and checkout Xerces society as well

Bees• Bees are our most important

pollinators• They are vital for our food crops as

well as natural ecosystem• Without bees the entire ecosystem

suffers• Bees suffer the most due to loss of

habitat and other concerns• Nationwide push to create

awareness about bees• Attracted to similar plants as

butterflies for nectar• Check out the pollinator species in

the resource guide and visit Xerces society

Birds• Birds need shelter and habitat

too• Bird habitats are a great way

to enjoy nature in your backyard

• Some species nest in grasses• Many birds feed on seed

heads of sedges and grasses• Hummingbirds are attracted

to nectar• Look for the bird symbol in

the species guide

Improve Aesthetics

• Raingardens are beautiful natural solutions that solve many landscaping challenges caused by stormwater & runoff– Prevent muddy puddles

caused by runoff pooling– Direct rain water away from

building foundation– Prevent patches of eroded soil– Enhance Landscape– Enjoy Colorful Native

wildflowers all year round

Stormwater Nightmares?

Easy to Maintain• Native plants are adapted to

local conditions• They are able to survive

changes in local climate conditions

• No need for special fertilizers, herbicides and insecticides

• Don’t need frequent watering (except during establishment)

• Can adapt to drought conditions• Thrive with basic weeding and

watering• Saves you time and $$$$$$

Environmental Education• Raingardens help educate

communities to– Protect and preserve our natural

water resources– Restore positive hyrdology cycles– Provide bird and pollinator

habitat– Learn about the importance and

function of native plants

• Raingardens are excellent teaching tools for – Classroom projects– Community gardens and

restoration projects

Steps to building a Raingarden

• Locate a potential site• Determine size of the

garden• Select Plants• Sketch a Plan• Construct the raingarden• Plant the Raingarden• Maintain

ENJOY!

Locate a potential site

• Ask yourself– Do you have any areas of

standing water?– What is the volume and

direction of runoff from impervious surfaces?

– How will you direct water to the raingarden?

– What is the most visually appealing location?

Locate a Potential Site• Where not to plant

– Within 10 ft of the foundation– Over septic systems

• Other considerations– Avoid locations under a tree.

Full sun to partial shade is most ideal

– Construction is easier on flatter surfaces than on steep slopes

– Ponding water may not always be an ideal spot. Site may need amendments or choose a spot with better infiltration.

Determine the size

• Points to consider– How much area is

available?• How big is the yard• Existing trees and dripline• Existing landscaping

– What activities are common in the area• Children or pets playing

– What size will optimize infiltration

Determine the size

Depth of garden• Typically raingardens are 4-

6” deep.• Guidelines for depth

– Less than 4% slope: 3-5” deep– 5% to 7% slope: 6-7” deep– 8% to 10% slope: 8” deep

Area of Garden• Estimate Roof Area then

estimate the amount collected from downspout (e.g roof area = 2500 SF and downspout collects 25%. Then 2500 x .25 = 625 SF downspout drainage area)

• A typical raingarden is 10% to 30% of downspout drainage area depending on depth and soil type

• So for 625 SF Downspout drainage area the raingarden would be 63 SF to 188 SF

Determine the Size

• Resources to help with calculating size– UW Publications:

Raingardens A how-to manual for homowners http://learningstore.uwex.edu/Rain-Gardens-A-How-to-Manual-for-Homeowners-P372.aspx

– Johnson County Soil & Water Conservation District http://www.jcswcd.org/Default.aspx?blockId=2&pageId=1114074

Determine the size• Be creative, these are

guidelines not rules– Raingardens maybe as large or

as small as you wish– Consider complementing

raingardens with rainbarrels– Divert excess flow from

rainbarrels to raingardens– Build few small raingardens

over time instead of one large raingarden

– Raingarden plants maybe used individually within landscapes as well

Select Plants• Color

– Create splashes of your favorite colors

– Think of patterns using colors– Grasses like Little Bluestem have

spectacular fall colors• Bloom Time

– Try to create year round color– Prairie Smoke and Columbine bloom

very early– Asters can provide late fall colors

• Sun/Shade requirements– Choose appropriately for your site

conditions– Look for these symbols in the GMF

species guide

Select Plants• Soil Moisture

– Choose wet adaptive plants for the bottom of the raingarden and the wet areas

– Choose dry adaptive plants for the berm and really well drained areas

• Height– Tall stature plants have a majestic,

rustic, and natural appearance – but may block views

– Short stature plants are popular for small urban landscapes but may limit selection

• What kind of wildlife do you want to attract– Remember the bird & butterfly icons

• GMF species guide provides all the information required to make selections

Sketch a Plan• Your raingarden design should be

based on– Size and location of raingarden– How you plan to divert water to the

garden

• Draw a rough sketch of your property with home and existing landscape

• Sketch out the area where you plan to install the raingarden

• Sketch out the path of waterflow– Downspout close to or feeds into

raingarden– Any downspout extensions or

channels you will construct to divert water

– Placement of rainbarrels and diversion of overflow if you plan to use rainbarrells

Sketch a Plan• Design the raingarden

– Raingardens can be of any shape but crescent, kidney & teardrop shapes are most popular

– UW Raingarden manual and several online resources provide designs and guidelines for your raingarden

– Many landscape professionals are also offering native raingarden design and installation services

– Be creative and design your own• Create patterns with color

arrangements• Play with textures mixing up plants

of varying heights or create patterns of heights

• Add wildflowers in a matrix of grasses and sedges

• Make sure to consider the sun/shade and soil moisture when creating your own design

Construct the Garden

ALWAYS CALL DIGGERS HOTLINE!!!!

• Strip Sod or Remove existing vegetation– Smother with black tarp– Smother with layers of

cardboard and newspaper– Use herbicide like roundup– Combination

• Rototill

Construct the Garden

• Level and Shape– Create raingarden base and

berm– Keep the base flat– Refer to Homeowners manual

for detailed instructions

• If necessary work soil amendments like sand, gypsum or peat into the base to improve infiltration– Useful for heavy clay or low

infiltration soils

PermaMatrix• Soil amendment option for poor depleted soils• Restores biological function to soils through

combination of carbon-based fiber, superior organics, micro-organisms, beneficial fungi, biochar, and water holding materials.

• Together these components create a growing medium that is not only optimal for seed and plant growth but creates a permanent and healthy growing environment

• Safe for all applications including sensitive waterways and shorelines

• Typically applied hydraulically, but can be tilled into soils

• Sold in 2 cu bales (3.5 cu uncompressed). $84.99

• Each bale covers 500 SF, may cover more area depending on soil conditions

• Many landscapers and garden store offer other soil amendment products and blends. If you have heavy clay or poor soil consider adding amendments to improve infiltration and encourage healthy plant growth.

Plant the Garden• Lay out plants according to your

design• Install plants

– Best to install on cool cloudy day or early morning to minimize transplant stress

– Hole should be twice the diameter and same height as rootball

– Gently remove plant from container and brush hand over rootball to stimulate roots

– Place plant in hole, fill hole and gently pack hole to remove excess air• Make sure roots are not exposed or

leaves too low

Plant the Garden• Mulch the garden

– 1-2” thick– Do not bury crown– Use double shredded mulch that wont

blow away or float away– Straw, grass and leaf clippings work well

too

• Water the garden– Water at least twice a week until roots

are established– Roughly 1” water per week– No watering necessary once plants

established

• Tips– Install plant identification stakes next to

your plants while installing– Consider installing a sign about

raingardens or natives to educate neighbors. You may make your own or buy one

Maintain the Garden

• Weeding– Hand pull any existing

weeds– Hand hoe to work soil and

sever roots of annual weeds– Spot Spray herbicides

• Mulch– Replace mulch regularly– A good layer of mulch

minimizes weed pressure

• Cut and remove dead plant material in spring

Enjoy!

Landscaping with Natives• Similar benefits to raingardens

– Natural– Easy to maintain– Prevents erosion– Infiltrates water/traps pollutants– Provides native habitat to birds and

pollinators

• Native seed and plants can be used in small urban landscapes in many ways– Short prairie gardens– Bird & Butterfly gardens– Mailbox gardens– Lakeshore buffer gardens

• Native plants can be used to create colorful landscapes instead of horticultural species

Landscaping with Natives• GMF Provides

– Various garden kits for landscaping– A wide selection of species that can

suit a variety of landscapes– Select species, sketch plans, install and

maintain similar to raingardens

• Seed vs Plants– Seeds

• Cost effective, maximize diversity, great for large areas, more naturalized appearance, perfect for habitat restoration

• Long establishment period, risk of seed loss, difficult in sloped, erodible and wet sites, requires patience and maintenance

– Plants• Immediate establishment, great for

urban and residential landscapes, flexibility in design and installation, great for sloped, erodible or wet site

• Expensive, not cost effective for large projects, does not have naturalized appearance of prairies

What to Expect from GMF• A great selection of native

plants for raingardens and prairie gardens

• 2.5” x 2.5” x 3.5” superior quality plants with excellent top growth and root development

• Cost sharing, so you pay almost half the retail cost

• Partnerships to promote rain gardens and native plants (Plant Dane!, Waukesha and MMSD)

Photo Gallery

Examples of raingardens and prairie gardens in various settings

Parking Lot Garden

Mailbox Garden

Backyard Raingarden

Downspout feeds into raingarden

Pewaukee Library Raingarden

Channel directs water into raingarden

Backyard Raingarden

Channel for directing water

Lakeshore State Park

Millennium Park - Chicago

Highline Park - Manhattan

Median Raingarden

Cayuga Court - Middleton

University Ave - Madison

Riverside Park - Beloit

Wind Point Lighthouse

Resources• For more information

– Take an Agrecol catalog or visit www.agrecol.com

– Visit the UW Arboretum and check out their native gardens and prairies

– Lady Bird Johnson Wildflower Center (www.wildflower.org) has plenty of resources, FAQ and contacts for designers, landscapers and suppliers of natives

– Join a Native Plant Society, Wild-Ones, Friends groups or local conservation group

• Links– UW Publications: Raingardens A how-to

manual for homowners http://learningstore.uwex.edu/Rain-Gardens-A-How-to-Manual-for-Homeowners-P372.aspx

– Johnson County Soil & Water Conservation District http://www.jcswcd.org/Default.aspx?blockId=2&pageId=1114074