Aerating a lawn…

Lawn Aeration Blog

September is the beginning of our fall lawncare season. Overseeding or reseeding lawns can be done throughout the month and at the beginning of the month we can fertilize our lawns. Toward the end of the month, fall weed control can begin, but not until our temperatures cool off more. One of the other lawn activities that may be considered is lawn aeration.

Compacted soils can inhibit the growth of your grass. When a soil is compacted, the soil particles are packed too tightly together to allow oxygen and water to pass through the soil. This can lead to shallow roots for the grass plants and in turn, can lead to less drought tolerance. Compacted soils can also lead to more thatch build up on the soil surface.

Thatch is the accumulation of dead grass stems that don’t become decomposed. In compacted soils, earthworm activity decreases, as does the activity of other decomposing organisms. The reduction in decomposing organisms leads to the build-up of thatch which can cause problems with the growth of the lawn. Lawns with a high thatch layer can begin to die because the thatch layer repels water keeping it away from the roots of the grass plants.

One of the best ways to reduce thatch and alleviate soil compaction would be to aerate the lawn. Many people interchange the terms “power raking” and “core aerating” when it comes to lawn aeration. However, these are 2 very different activities. Power raking is a more intense form of reducing the thatch layer on the lawn. It is only recommended when a thatch layer is more than ½ inch because at that point it would be necessary to renovate a lawn rather than just to core aerate.

Aeration equipment
Core Aeration Equipment, Photo from John Fech, Nebraska Extension Educator

Core aeration is the method of aerating your lawn most recommended. This is the method where a machine is driven over the lawn while it pulls out many small, core soil samples throughout the lawn. These cores are laid over the top of the lawn but help by leaving holes in the soil surface for water and air to move in and they will fill back in. Core aeration will also sever the roots of the grass plants which stimulates the plants to grow new shoots to fill in the holes.

It is best to aerate a lawn in the spring or in the fall. This time of year is best because the plants can recover before winter or summer conditions that are sometimes difficult on our plants. It is also a good time of year to aerate due to the fact that the soil has more moisture in it than in the other dry months of the year. It is not recommended to aerate a lawn when it is too dry or too wet because it is more difficult to get the tines into the soil which can damage the plants more. It is not necessary to aerate your lawn every year, or sometimes at all. If your thatch layer starts to build up, you drive on the lawn a lot causing more compaction, or if the lawn begins to look thin, aeration can be done. At most, it would only be recommended to aerate a lawn every 3-5 years.

Fall Yard and Garden Issues

Fall will be here before we know it. Take the time to read this to help you through all of your horticulture and insect issues during the fall months.

Bare lawn in need of overseeding.
Bare lawn in need of overseeding.

For fall lawncare, September is a good month for overseeding, fertilizing, and aerating your lawn. If you have bare spots from the floods or have a thin lawn, you can overseed in the month of September, before the 15th will have better establishment before winter, Kentucky bluegrass and tall fescue are the best choices for seed in Nebraska. Remember to fertilize with the holidays, and Labor Day and Halloween are coming up for our final two applications for this year. If your lawn has a deep thatch layer, over 1 inch, you may need to aerate your lawn, fall is a good time for aeration as well.

Weeds in a lawn

Weed control is better in the fall. Many of our perennial weeds and winter annuals will get much better control if they are treated in the fall. This year has been a great growing season for many of our lawn weeds, especially clover. Perennial weeds such as Dandelions, creeping Charlie or ground ivy, and clover, are best controlled in the fall with either 2,4-D or Triclopyr products. Remember to apply these chemicals on days when the temperatures are predicted to be at or below 80 degrees for 72 hours. This is the time of the year when these weeds are taking their nutrients back into their roots for next season’s growth, so they will take the herbicide with them to get a better kill. The winter annuals such as Henbit are just beginning their growth in the fall so it is best to treat them now rather than in the spring when they are almost done with their growing season.

It is finally getting close to the time of the year when we can begin cutting back our perennial plants. Once these plants die back in the fall, when their leaves turn brown, we can cut them back for the year. Peonies and Iris are two plants that should be cut back in the fall to avoid diseases spreading from this season to next since these plants tend to get leaf spot diseases annually. When you go to remove the spent leaves, you can also divide these plants and transplant them if you need them in a different location. Avoid pruning roses and butterfly bushes until the early spring to avoid problems with moisture getting into the hollow stems of these plants. If you have a shrub that blooms early in the spring, such as lilac, forsythia, weigela, some spireas, and some hydrangeas, wait to cut those back until after bloom next spring to avoid removing flower buds that are already on the shrub for next year.

Center photo by S. Cochran, Lancaster County Extension
Center photo by S. Cochran, Lancaster County Extension

Watch for fall invading insects in your home in the fall. This is the time of year when many insects will begin to invade our homes. As it begins to get cooler outside, insects move into our homes to stay warm. Many of the insects we see in the fall inside our homes include boxelder bugs, Asian multicolored ladybeetles, stinkbugs, spiders, millipedes, centipedes, and ants. These insects are mostly just a nuisance to us when they come into our homes. The best control for these would be to seal up all cracks where they can enter our homes and to use the insect barrier sprays around the home, especially around doors and windows.

Fall Lawncare

fall landscapeAs we draw closer to fall, we can start to prepare our lawns for winter. I wanted to take time, this week, to cover all of those items on your fall lawncare “to do” list.

It is now time to reseed your lawns for the fall. This is best done in the late summer or early fall, anytime between August 15 and September 15 of the year. The rule of thumb is that that for each week grasses are seeded before Labor Day, maturation is speeded by two weeks. If you reseed after September 15 you will probably have some success, but not as much. The seed that you put out on the ground may sprout and some might even overwinter, but much of it may die from winterkill because the root systems will not be fully developed. If you are a homeowner who wants to sod an area of your lawn, you can do that until they can no longer cut it from the fields. Do remember to keep newly seeded or sodded areas watered throughout the fall and in the spring.

Bare lawn in need of overseeding.
Bare lawn in need of overseeding.

Good turfgrass choices for Southeast Nebraska include Turf-type tall fescue or Kentucky Bluegrass.   Using seed that is 100 percent of either of these or a mix of the two types would be great choices for Nebraska. You can buy mixes of turfgrass seed, but avoid mixes that contain annual ryegrass, ‘Linn’ perennial ryegrass, or ‘Kenblue’ Kentucky Bluegrass. Make sure that the grass you buy contains less than 0.3 percent weed seed and no noxious weed seeds. We can also use Buffalograss in our lawns for a warm season grass, but warm season grasses should be plugged in June and July.

As for fertilizer applications, the fall fertilization is the most important fertilizer application for a lawn. Two applications in the fall are recommended for Kentucky bluegrass and only one is recommended for tall fescue, but one application for either species is better than none. The timing for fall fertilizer applications is Labor Day and Halloween if you do two applications and Halloween if you do only one application.

The fall is the best time to control broadleaf perennial weeds such as dandelion and clover. You can add a broadleaf herbicide to your lawn fertilizer to get a two-for-one application. It is often sold in stores as a combined product. The best herbicide choices for homeowners would be anything that contains 2,4-D or a triclopyr product for clover and ground ivy or creeping Charlie.

Photo by Nic Colgrove
Photo by Nic Colgrove

If you need to aerate your lawns, now is a good time to do that. You can still aerate your lawns into November if you don’t get around to it until then. Aeration is best done in the spring or the fall of the year, but it is not necessary to do it every year, if you don’t want to. Aeration is done to break up a heavy thatch layer in the grass and to reduce the compaction of the soil. The thatch layer is the layer of dead organic matter in between the grass blades and the soil line. Leaving the clippings on the lawn does not increase the thatch layer, in fact it can actually give you enough nitrogen to replace one fertilizer treatment for the year. If your thatch layer is more than one half of an inch, you may want to aerate your lawn, if it is less than that, you may decide that it is not necessary to aerate this year.