It is time for all that fun, fall lawn activity. There are so many things we can do to help our lawns in the fall. If your lawn needs help, this is the time to fertilize and overseed. On the other hand, if your lawn looks great, you can fertilize and spray weeds to maintain the good look of your lawn.
Overseeding the Lawn
If you lost patches due to the drought this year or just need to thicken your lawn, late August through early September is best for seeding turf. Plant the type of turfgrass you currently have in your lawn or go with a blend of Kentucky bluegrass and Turf type tall fescue and use blue tag certified grass seed for highest quality and least weed issues.
When overseeding, it can be helpful to aerate the lawn first so the seed can drop down into the plug hole. You can aerate annually if you choose but it isn’t necessary every year, only as the thatch layer increases. If you are just thickening up the stand or filling in bare spots, just spread the seed and then use a stiff-tined rake to get the seed down to the soil.
If you plan to kill off existing vegetation first, you can use glyphosate, or Roundup, but it needs to be done 1-2 weeks ahead of seeding. Do not use pesticides on the newly seeded areas until it has been mowed 3 times, with the exception of mesotrione, or Tenacity, which can be used at seeding. You can use a starter fertilizer when planting new grass. Always read and follow the label when using any pesticides.
Fall Broadleaf Weed Control
Perennial broadleaf weeds including dandelions, creeping Charlie or ground ivy, and clover are best controlled in the fall once the weeds have begun their preparations for winter. In the fall, these perennial weeds will move sugars that they use for energy from the above ground portions of the plant down into the roots to store them for next spring. If they are sprayed during this phase of their lifecycle, they are more likely to take that herbicide down into the roots, making pesticide applications more effective than if done in the spring. Spray weeds with a 2,4-D product 2 or 3 times from late September through the end of October. Wait to spray after temperatures consistently drop to below 80 degrees so the herbicide doesn’t volatilize in hot, humid weather and harm other plants.
Henbit can also be controlled in the fall with either a pre-emergence herbicide in early fall before it germinates or with a post-emergence herbicide later in the fall. A later October application of 2,4-D products can control later germinating winter annuals like henbit.
As for fertilizer applications, fall fertilization is the most important application for a lawn. However, fall fertilization recommendations have been adjusted over the past couple of years for best efficacy. Applying a slow-release fertilizer from Labor Day to mid-September is still recommended. Apply a granule with 50% slow-release nitrogen or less. If additional nitrogen fertilizer is required later in the fall, use a product with a quick release nitrogen in mid-October. New research shows a second application of nitrogen fertilizer may not be necessary, wait to see if the lawn maintains a medium-green hue in early October, if not a second application can be added.
*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.
If you have any further questions please contact Nicole Stoner at (402) 223-1384, firstname.lastname@example.org, visit the Gage County Extension website at www.gage.unl.edu, or like my facebook page at http://www.facebook.com/NicoleStonerHorticulture and follow me on twitter @Nikki_Stoner