Build Your Own Rain Garden

A Rain Garden is a shallow depression in your yard that is planted with native wetland or wet prairie wildflowers and grasses. A rain garden is designed to naturally collect water that runs off from your roof or is discharged from your sump pump. Rain Gardens are gaining in popularity because they are low-maintenance and attract birds and butterflies while making good use of stormwater runoff.  
Learn to build your own rain garden

City of St. Charles Grass and Flower Seed Mix​


Beginning spring 2017, the City of St. Charles Department of Public Works will provide residents interested in planting a rain garden with (2) seed packets, one for grasses and one for flowers. The packets contain a mix of seeds for low lying moist areas that tend to stay damp throughout the growing season. These seeds are an excellent choice for establishing native plants. The species in this mix tolerate periodic flooding for a day or two, as well as dry periods between rainstorms. Once established, these plants are an excellent way for residents to improve stormwater quality by maintaining a rain garden with native vegetation.

This mix is not recommended for dry, sandy soils that drain rapidly and do not retain moisture.  
Rain garden seed is available at any of the following locations:

Department of Public Works 
2871 Elm Point Industrial Dr. 
St. Charles, MO 63301

Department of Engineering
200 North Second Street 
2nd floor
St. Charles, MO 63301

St. Charles Parks & Recreation 
1900 W. Randolph St. 
St. Charles, MO 63301

St. Charles Senior Center
1455 Fairgrounds Rd
St. Charles, MO 63301

Planting Recommendations

When to Seed - Pros & Cons
Time Advantages Disadvantages
FALL
September 1 -  First freeze
- Seed overwinters and comes up in spring on its natural schedule when conditions are right. This breaks most seed dormancies naturally over winter.
- Flowers have increased spring germination with fall seeding.
- Recommended for droughty, sandy soils because seed germinates earlier in the season, before summer heat when moisture levels are optimal.
- Recommended for clay and wet soils. Clay and wet soils are easier to work in the fall than in spring. Fall seeding on clay and wet soils encourages earlier germination and better root development prior to the onset of summer. 
- Fall seedings do not require watering, as the seeding is dormant.
- Warm season grass seed typically exhibits reduced germination.
- There is no opportunity for early spring weed control by cultivation or herbiciding.
- Be careful on erosion prone sites. Plant erosion prone sites paired with a nurse crop of annual rye or oats to help hold the soil over the fall and winter. 
- Annual Rye is planted at a rate of 15 pounds per acre in fall (and 5 pounds per acre in spring).

EARLY SPRING March - April
- Results in better flower germination than in late spring.
- Spring rains make watering less critical. 
- Warm season grass seed has better germination than in fall.
- Best option for sandy soils if unable to plant in fall.

- Limited opportunity for early cool season weed control.
- Clay soils are too wet in the spring, and by the time they can safely be worked, the heat and drought of summer are upon us, which can reduce the success of seedling survival.
- Not recommended for heavy soils, as it is difficult to work these soils if wet in spring.

LATE SPRING May - June
- More time for good soil preparation-particularly important on heavy soils.
- More time for spring weed control prior to seeding. 
- Optimal time for ideal germination of warm season grasses.

- Increased chance for low moisture conditions or the onset of drought later in season.
- Reduced germination of some flower species.

Rain Garden Information