Answering Your Fall Lawn Care Questions

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grassAdam Thoms of Iowa State University Extension and Outreach answered all your questions about how to tend to your lawn this fall.

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What is the best strategy for weed control as fall approaches?

A healthy lawn this the first and best strategy. Strong competition from healthy turfgrass will help more than anything against weeds. Fertilizing the yard with 0.75 to 1 lb. of nitrogen per 1,000 square feet now, and again in early November will help give the turfgrass the nutrients it needs for optimal growth and health. Also making sure bare spots in your yard have seed in them will help to fill in areas of the yard that otherwise could be open for weeds to invade. 

What are some characteristics of a good herbicide to use in the fall?

Fall herbicides should focus on broadleaf weed control. We suggest spraying for these weeds after the first frost. When selecting a broadleaf herbicide, make sure it has at least 2-3 different chemicals. The reason we want different chemicals is that some chemicals work better on certain broadleaf weeds than others, so getting 2-3 chemicals in the tank will help with better broad-spectrum control. The fall is not the time to treat for crabgrass, this is a summer annual and the frost will kill crabgrass. It will germinate again next April to May so do not worry about it until the spring.

What weather conditions should we apply herbicides in?

You want to apply herbicides when there is little to no wind, the temperatures are less than 80 degrees, and there no rainfall in the forecast for at least a day. If you are using a granular weed and feed product you will want to apply this right after it has rained or after a heavy dew. These products only work if the leaf tissue is wet, as the product has to stick to the leaf.

Is fall a good time to aerate the lawn? What is a good strategy for lawn aeration?

The fall is the best time to aerate a yard, September and October are better than November to aerate because it allows the yard some recovery time. The best aeration is to use a machine that pulls a plug, and go at least two different directions over the yard.

Can we still use grass clippings for composting and mulch even if they have been treated with fertilizer and/or herbicides?

Always read the label to see if you can use the clippings. The label will tell you if it is safe to use the clippings or not.

Can raked leaves be used for composting?

Raked leaves can be mulched up and returned to your yard as extra fertilizer, I have seen piles as high as 18 inches mulched into the turf. Make sure you chop the leaves up fine enough that they fall into the canopy and do not sit on top of the turf and smother it. This may mean mowing the yard two or three times if you have a bunch of leaves on the yard.

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