The document provides instructions for designing and building a rain garden. It outlines 7 key steps: 1) evaluating storm water runoff on the property, 2) determining a suitable location for the garden, 3) sizing the garden based on roof or surface area and average annual rainfall, 4) shaping the garden with a bowl or flat bottom, 5) preparing the site and installing the garden, 6) selecting suitable plants for different moisture zones, and 7) maintaining the garden during establishment. The garden is designed to capture and filter storm water runoff on the property.

1. Lecture Notes
How to Design and Build Your Rain Garden
1. Storm Water Run Off Evaluation
o Sketch the property
o Wait for rain
 not at the beginning of a storm
 not during the first storm after a dry spell
o Walk the property
 record run off observations
 note high and low spots
 downspouts, impervious surfaces, steep terrain, etc.
2. Determine a location
o What do you want to do?
 roof run off
 lawn run off
 driveway, walkway or patio run off
o Do you wan the garden in a different location?
 underground pipes
 swales
o Other factors to consider
 10 feet down hill of the building
 beyond the drip line of a tree
 away from septic systems and utilities
 avoid steep slopes
 avoid areas that don’t drain
 soil type‐ sand, silt, clay
o The garden MUST drain.
o Infiltration test
 test hole 6‐12 inches wide and 12 inches deep
 add water
 refill if dry season
 look for complete drainage in 24‐48 hours
 amending the soil
 add organic matter such as compost, humus, well rotted
manure
 sand‐ use only coarse builders’ sand not fine play sand
3. Size the garden
o Storm water calculation
 1 inch of rain on a 1000 square foot roof yields 623 gallons of
water
 multiply the footprint of your roof by .623 to find run off in
gallons for a 1 inch rain storm
 calculate average annual run off by multiplying the above
number by 42 which is the average yearly rainfall in this region
o Size must make sense in your landscape!

2.
4. Shape the garden
o Bowl shaped bottom
o Flat bottom
5. Site preparation and garden installation
o Pennsylvania One Call System 8‐1‐1 or 1‐800‐242‐1776
 It’s free and quick
o Mark your design
o Remove the turf
o Dig out the garden
o Amend the soil if necessary
o Create the berm using the removed soil
o Berm will be higher on the down slope side of the garden
o Cover the berm to prevent erosion
o Lay out the plants
o Plant
o Water the plants
o Apply 2‐3 inches of mulch
o Line any swales with rocks or stones
6. Plant selection
o Multiple zones
 wet zone‐ deepest, wettest area
 middle zone‐ holds water but drains sooner
 transition zone‐ upper zone, closest to rest of yard
 berm‐ dry
o Refer to PennState Extension plant list at
http://extension.psu.edu/gardening/maescapes/rain‐
gardens/plants‐rain‐gardens
o Match cultural requirements
 sun/shade
 moisture
 size at maturity
o Four season interest such as berries, fruits, pods, etc.
o Use native plants
 beauty
 ease of maintenance
 wildlife habitat and food source
 deep root zones
7. Maintenance
o Moisture to help establish the garden
o 1, 3, 5 Rule until the garden is established
o Check the berm for stabilization
o Check the mulch for flotation movement
o Weed as necessary