Gardening Through Plastic - Weed Management
A 3 mil black polyfilm plastic sheet covering your plot will eliminate weeds, conserve moisture, and warm the soil. A 20 ft. X 25 ft. roll of 3 mil polyfilm is available at Menards for $11.99 or a 10 ft. by 25 ft. roll for $5.28. The Madison west Menards is located at 430 Commerce Dr., just south of Mineral Point Road and west of the beltline.
Laying the plastic
- First, till the soil by spade or roto-tiller. No need to remove weeds or rake smooth. You can enrich your soil by spreading mulch, leaves, straw or manure on the soil before tilling.
- Unroll the plastic and shape it to your plot by folding excess underneath or cutting with a scissors. (Best to do this on a quiet day with no wind.) Anchor the corners with a stone, log or shovel of dirt.
- On one of the longer sides of your plot, use a shovel to dig a shallow trench, about 4 inches deep and as wide as your shovel, directly under the edge of the plastic sheet. Pile the dirt to the outside or into a cart. Place the edge of the plastic in the trench and cover with the soil you have removed, securely anchoring the plastic on one side.
- Repeat the trenching and burying of the edge of the plastic on the three other sides. Try to avoid slack in the plastic sheet.
- After burying the entire sheet, eliminate large bulges or ripples by placing stones or logs on top of the plastic.
- If you must use more than one sheet of plastic the two sheets should overlap by at least one foot. Place a line of stones, logs or soil on the overlap. Any wind that gets under the plastic will lift the entire sheet.
Planting through plastic
- Started plants can be transplanted thru plastic by cutting a small "X" about 4 inches by 4 inches. For very small or tender plants place a few small stones on the plastic to prevent the flaps from whipping in the breeze. Spacing of plants should be the same as with open planting. On sunny spring days you will be amazed at how warm the soil under the plastic will be.
- Seeds such as squash or cucumbers can be planted by cutting a 10 inch hole in the plastic.
Watering through plastic
- After the first rainfall following installation simply look for the puddles on top of the plastic sheet and using a hoe chop a small slit at the deepest point.
- Water will slowly seep into the soil and spread to adjacent areas. Because the plastic prevents evaporation you seldom need additional water. But if you do sprinkle, the water will disperse just as the rainfall does.
Removing the plastic
- 3 mil plastic will deteriorate after one season so all plastic must be removed and placed in the large dumper bins at the entrance to the gardens at the end of the season.
- After a few hard frosts (generally late October) stems and vines can be removed and the plastic can be pulled up in large pieces.