Master Gardener

Bev Johnson

Stop mowing the lawn as soon as the temperatures drop below 50 and stay there. By then you should have cut it to about 2 ½ inches tall at the last 2 mowings. This will reduce the amount of leaf tissue over winter and can reduce the amount of snow mold you will need to address in the spring. 

Never leave piles of grass clippings on the lawn at any time of the year. The same goes for leaves. Get the majority off. Leaving too thick a layer of leaves blocks out sunlight and can leave you with either dead grass next spring or a really thin lawn. Leave a thin layer of chopped leaves as they will rot and disappear by spring and actually feed the grass. 

What to do with the excess leaves? Chop them up if you can and use them to cover your flower beds to at least a foot deep. This will prevent frost heave, and since it keeps the soil warmer later, will give your flowers a few more days to prepare for winter. 

In the spring, unless you really enjoy pulling weeds, leave the leaves on for mulch. It will eventually disappear into the soil due to the action of the millions of tiny critters that live in healthy soil. Save a good pile of your chopped leaves to add to the beds in July when the bare soil will start to appear due to this activity.

If you haven’t done it already, deal with broadleaved weeds now like Charlie. The best control is when the temps are above 50 but cooler than 80. Unless we get some good soaking rains, water the area before you treat it. Why the heck should I water weeds I want to kill?  Seems counterproductive, doesn’t it?  It’s because the weeds need to pull the herbicide down into the roots to be effective and they can’t do that if the soil is dry. In fact, you may injure your grass if the soil is too dry as it can become susceptible to broadleaf herbicides under very dry conditions.

If you enjoy mowing the lawn, now is the time to apply a late season of nitrogen fertilizer—after you water well. This time of year, the nitrogen is taken up into the plant and stored in the crowns, rhizomes, tills and/or stolons where it can be quickly accessed next spring. Never apply fertilizer to frozen ground. It needs 2-3 weeks of unfrozen ground for the roots to take it in for growth next spring. It will be easy to tell where the grass has had a late season taste of nitrogen as it will be the first lawn to green up in the spring.

If you still have some thin spots in the lawn, you can try dormant seeding. Wait until the ground is cold but before it is frozen. Mix the seeds with soil to protect it during the winter. The trick is to seed late enough that the seeds don’t germinate until next spring. Good luck with that. It’s impossible to predict what Ma Nature will get in her head to do any time of the year.

Keep watering, especially shrubs, trees and flowerbeds. All growing plants need an inch of moisture a week. While there may be some stored, don’t depend on it. If we get an “open” winter with little or no snow, many plants will either turn up their toes and out right die, or just barely hang on until they do get enough water to survive if not thrive.

That’s your fall chore list—water, mow, pick up leaves, mulch, kill weeds, feed grass. Get with it.