We are into the last week of August. How does your lawn look?

By this time of the summer, your lawn may look a bit ragged. There may be bare spots, or the weeds may have managed to creep into the lawn. Now is the time to fix up those problems in your lawn. Here’s what you need to do.

Fall is a good time to control weeds in your lawn. Weedkillers work best when applied to weeds that are actively growing. Yes, the weeds are actively growing in your lawn now.

In the spring, cool soil temperatures usually mean that weeds are slow to grow in your lawn. Oftentimes, most weedkillers that you apply in the spring kind of work, but not too well, because in the spring, the soil takes a long time to warm up.

In the late summer, the weeds are preparing for winter by making lots of food and storing it in the roots. This allows the weeds to begin growing again in the spring.

When you apply a weedkiller in the late summer or early fall, the weedkiller is taken down to the roots and kills them. If the roots are dead, the weeds are not coming back in the spring. Weedkillers are applied to the weed leaf, and you should allow 24 hours without rain or irrigation. This allows the weedkiller to be absorbed by the leaf and then taken down to the roots.

You may have noticed that the crabgrass has formed its seed heads. Once the seeds mature, they drop onto the ground. Once the frost comes along, the crabgrass plants that are in your lawn will die and you will never see those plants again. However, those seeds that fall on the ground will sprout in the spring, and new crabgrass plants will grow in your lawn.

Over the years, there has been some debate over applying a crabgrass control in the fall. I know people who have done this, but they seem to have limited success. My recommendation is to apply the crabgrass control in the spring when the seeds are beginning to open.

The usual crabgrass control methods work by killing the seed just as the seed sprouts. Crabgrass seed has a hard “shell” that makes it hard for crabgrass killers to work until that seed is splitting open. To me, that is why a fall application of crabgrass control doesn’t work all that well. In the fall, the seed isn’t opening up. If it did, any crabgrass plant that sprouted would be killed by a frost.

To control the crabgrass seed, wait until the spring.

Fall is an ideal time to apply lime to your lawn. If the soil is too acidic in your lawn, the roots of the grass do not take up the lawn fertilizer you apply during the season. When you apply lime, the acidity of the soil is neutralized and the grass easily takes up the fertilizer you apply.

Depending on the type of lime that you use, it can take up to six months for the lime to really do its job. If you apply the lime in the fall, by the time spring rolls around, the lime has done its job and that first application of lawn fertilizer can really do its job of getting new blades of grass to grow.

If you haven’t fertilized your lawn in more than eight weeks, it is time to do another application. At this time of the year, you should be applying a weed-and-feed type of fertilizer, or you can apply just a regular lawn fertilizer. I would not apply a fall- or winter-type of lawn fertilizer at this point. Use the fall/winter fertilizers in October.

By applying a regular lawn fertilizer or a weed-and-feed fertilizer now, you get the grass really growing again. When the grass is really growing again, it makes the application of those late-season fertilizers more effective.

Well, that’s all for this week. I hope you have a happy Labor Day weekend. I’ll talk to you again next week.

Tim Lamprey has worked in the lawn and garden industry for 45 years. 

Recommended for you