Be Gone, Lawn!

Research Question:

How effective is carpet in killing lawn grass and preparing a bed for planting?

Mulching is the practice of adding rough material to the garden. Sometimes this is done to add air and water holes to compacted soil. Sometimes it is done to create a layer of leaves or clippings on top of the soil to preserve heat or moisture. In this experiment, you will investigate a third use of mulch: weed control. You will help determine whether adding a layer of carpet to a lawn can kill lawn grass and get the space ready to become a garden.

The practice of adding carpet to the lawn is somewhat controversial, primarily because many carpets are not made of natural materials. They may also have pesticides on them to deter bugs. When you do this experiment, use a scrap of natural wool carpeting.

Materials:

• 2x2 offcut of natural wool carpet
• Two areas of lawn
• Notebook and pen

Experimental Procedure:

1. Get an offcut of wool carpet. This piece of carpet should be no more than 2 feet by 2 feet.
2. Choose an area of lawn that you would like to remove. This area should be at least 4 feet by 4 feet. Examine the area for grass that is dead or dying and areas of moss or other plants. Measure the area that is not healthy grass.
3. In the spring, place the piece of carpet on one side of this grassy area. The other side is your control area.
4. Keep the carpet on the grass for at least a month.
5. At the end of this time, remove the carpet. Examine the area for grass that is dead or dying and areas of moss or other plants. Measure the area that is not healthy grass.
6. Do the same examination on the control area.
7. Compare the area of healthy grass in the beginning with the area at the end of the experiment. Convert these numbers of percentages. For example, if you had 3.5 square feet of healthy grass in the carpeted area at the beginning and now you have 1 foot of healthy grass, 88% of the grass was healthy in the beginning and 25% was healthy at the end. This is a 63% reduction.
8. Compare the percentage change in each grassy area. Did the carpet cause a large change in the grass cover?

Terms/Concepts: Learn why people might want to remove lawn grass to make a garden bed; Learn what lawn grass needs to grow;  Learn how to use carpet to create a garden bed

References:

• http://www.thegardenersescape.com/Articles/Composting/DifferentTypesOfMulch.htm (The Gardener’s Escape)
• http://www.hc-sc.gc.ca/cps-spc/pubs/pest/_fact-fiche/hl-ps-start-amen/index-eng.php (Health Canada)
• http://eap.mcgill.ca/publications/eap64.htm (Ecological Agriculture Projects)