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Extension programs are available to all without regard to race, color, national origin, religion, sex, age, or disability.

The Green Scene

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November, 2010

Volume 8, Issue 11

Marion County Extension1445 Lake Dr. PO Box 409Knoxville, IA 50138

Phone (641)842-2014Email:xmarion@iastate.edu

Rain gardens are one of the hottest new trends in garden-ing this year. Central College has added one to its campus

and just last month Knoxvilles city and water utility crewsbegan installing one on the east edge of town (where theold Maid-Rite once stood) in preparation for turning theproperty into a small park and welcome sign area.

Why the big push for these specialized gardens? Thinkimproved water quality for our city, state, and country. Ascities and suburbs grow and replace forests and agricul-tural land, storm water runoff from parking lots, pavedroads, roof tops and other hard surfaces increases dramati-cally. The runoff not only increases flooding, but perhapsmore significantly, carries pollutants such as motor oil,chemicals, and trash into waterways such as CompetineCreek, Lake Red Rock, the Mississippi, and ultimately theGulf of Mexico. Slowing down the water and trapping itso that it must go down throughthe soil helps filter outthose pollutants, much the way terraces and tiles work toslow down and direct water in corn and bean fields.

The garden at the east end of Knoxville is a specialized

rain garden technically called a bio-retention cell. Be-cause the natural soil in the area has been altered andcompacted, a drain tile was installed in a gravel bed toensure that the water from heavy rains moves throughthe gravel and sand. When a heavy rain occurs, theoverflow of water will enter an inlet at the west end ofthe garden. This inlet is currently sticking up out of theground but it will soon be cut down to nearly groundlevel and covered with a trap to prevent trash from en-tering. It is connected to the underground tile which

runs west to east, sloping downward and ultimately connecting to the storm sewer. Water is slowly released viathe drain tile, mimicking the way groundwater releases ait moves in natural soils.

How can that really help? Wont the water from the twstreets still race to Competine? Yes, but not as muchand thats another point; every little bit helps. In addi-tion, a cut-out in the Montgomery Street curb will chan

nel storm waterfrom the street

into a secondgarden plannedbelow the first.In the spring na-tive plants will beinstalled that willfurther help re-tain the waterand cause it tofilter downthrough the soil.

No matter where you live, adding a rain garden to youryard can help manage storm water runoff and better pro-tect the water quality of our streams and lakes. Keep inmind that a rain garden is not a boggy area; rather it needto be located where the water can easily flow. It should blocated away from building foundations, utilities and sep-tic systems. For more information go towww.rainscapingiowa.org/.

Why a Rain Garden?

Inlet Pipe

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The Green Scene is a tip sheet developed by the Marion County Extension Office to inform people of horticulture events, problems, and interas. Let us know if you want to be added to our mailing list. Some issues are also available atwww.extension.iastate.edu/marion/. This m

has been prepared Karen Ackley, Agriculture Program Assistant. If you have questions, please contact the office at (641) 842-2014.Sincerely, Dale R. Miller, County Extension Education Director

November Checklist Finish planting tulips. Dig your canna and other tender bulbs. Dry them for a week or so

by putting them in a single layer on newspapers covering your garagefloor. Store them in a cool dark place for the winter.

Clean up all the diseases and insect-infested foliage and fruit from thegarden and orchard to prevent further spread next year.

Place wire netting or other protectors around young fruit trees in sec-tions where rabbits and mice abound.

There is still time to move or set out deciduous trees and shrubs. Itslate for evergreens.

Dont allow the lawn to go into winter with too much top growth.Two inches is plenty; more might be injurious by killing the rootsand being difficult to mow in the spring.

Each year Kathy Douglas of the KnoxvilleFederated Garden Club sponsors a con-test for those who maintain plots at theBessie Spaur Butterfly Garden. The gar-den, located south of the Knoxville Hos-pital & Clinics, is divided into more than40 plots. Each plot is maintained by anindividual or group throughout the grow-ing season. A committee from the Gar-den Club judges the plots periodicallythrough the season and awards out-standing care and results at the end ofsummer. This years first place winner isMarolyn Jordan. Her plot #34 (picturedhere) was deemed most attractive and well

maintained throughout the spring and summer. Other winners include Dixie Roorda (beds 2&3),and Karin Graham (beds 19, 20 & 21). Ellie Davis, the Marion County Master Gardeners, Connie

Israel, Rachel Cecil, Pam Burk, and Sherry Luedtke re-ceived Honorable Mentions. The committee awardedthe Most Improved Plot award to Carol Kozac, LetaBurke, Jessica Moon, Nancy Geer & Barb Waters, SandyRichardson, and Amy Chavez.

The butterfly garden is open to the public throughoutthe year. It has been used for picnics (such as the onepictured at left for the Master Gardeners in August),

weddings, and personal retreats. A big thank you to allthe volunteers who make it such a pleasant place to visit.

Jordan Wins 2010 BSB Garden Contest!