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.

Do I really need to rake?

fall landscape

November means fall is in full swing. The leaves of our trees begin to turn color and then fall to the ground making the ground colorful and giving it that characteristic “crunch” when you walk on the lawn. Why do some trees take so long to drop their leaves in the fall? And why do some hold onto the leaves throughout the entire winter? Finally, what do you do with the leaves when they fall to the ground?

Leaves fall to the ground in the fall to remove living material for the winter months. During the winter evergreen trees continue to transpire which can sometimes cause winter desiccation and browning on the needles if they lose more water than they take in. Deciduous trees lose their leaves to reduce the amount of living material necessary to support during the winter months and to reduce winter desiccation.

Each tree differs on how fast they lose their leaves. This is dependent on both the genetics of the tree and the environmental conditions they have faced this year. Two trees of the same species can lose their leaves at different times of the year based on the environment that is specifically surrounding that tree, or the microclimate. The environmental factors that affect when trees lose their leaves include prolonged drought, disease and insect pests, sunlight exposure, day length, colder air temperatures, frost timing, winds, soil, and water differences, according to Ted Griess, UNL Extension Horticulture Assistant. On years with extraordinarily hot and dry summers, the leaves tend to turn to fall color and drop off the tree much earlier than years of normal or cooler and wetter conditions throughout the summer.

Some trees, especially pin oak trees, hold onto their dead leaves throughout the entire winter and don’t lose the leaves produced this year until new leaves begin next spring. There is nothing wrong with this, it is a natural occurrence for some tree species.

Shagbark hickory, flickr, Nicholas A. Tonelli
Photo of Shagbark Hickory courtesy of Nicholas A. Tonelli, via Flickr creative commons license

Now that the leaves are falling, what do we do with them? It is not good for the lawn to leave the fallen leaves on the turf for the winter months. The leaves that fall can become matted on the grass and suffocate the lawn underneath. So, it is important to remove leaves from the lawn in the fall. This can be done with a rake or with a lawnmower. You can use the lawnmower to break up the leaves so that they go down into the turf and won’t suffocate it. You can also use the lawn mower to bag up all of the leaves as they fall. Mulching the leaves into the lawn will not add a thatch layer to your lawn. The leaves break down quickly and will not be a problem. Either way you do it, with a rake or a lawnmower, make sure that you get the leaves off of the lawn before winter.

After you have finished mowing the last time for the season, and have mowed up all your tree leaves, you should prepare your lawn mower for winter. Clean up the lawn mower and be sure to get all the grass off the blades and off of the underside of the deck. It may also be a good idea to sharpen the blades before you put it away for the winter so you don’t have to do that in the spring before you get started mowing.

Spring Lawncare

Spring Lawncare, blog post

April is finally here, which means spring should be bringing in warmer weather. April is a good time to get out and start working in the lawn and garden to prepare our yards. To help ensure that you have the best lawn on the block, here are few tips to improve your lawn this spring.

April is a great time to overseed your lawn. If you had some spots that were flooded out last spring, now is a great time to get some new seed planted. The beginning part of April is best for seeding lawns, but it can be done until the end of the month. Frequent, light irrigation is necessary to keep newly seeded lawns moist. It may be necessary to water twice a day to keep it from drying out and dying. Straw mulch can be applied to keep the seedbed moist, but it is not necessary and can bring problems with weed seed that is often a contaminant of straw. Do not apply any pesticides to newly seeded lawn until you have completed 2-3 mowings. Also, do not try to overseed right before or right after applying crabgrass preventer as this chemical will prevent the germination of your desired grasses as well.

We often face difficulties with weeds in our lawns. The key to weed management is to keep your lawn healthy to avoid weed infestations and to identify the weed before chemical controls are used. Many of our herbicides are specific to either a grass weed or a broadleaf weed and won’t work on the other weed type. Also, you need to know the weed to know the lifecycle for when the best time is to manage that weed with a chemical. As I stated in my previous news column, henbit is a winter annual and should only be chemically controlled in the lawn in the fall, the spring is too late.

crabgrass, Joseph Berger, Bugwood
Crabgrass Photo By: Joseph Berger, Bugwood.org

Crabgrass pre-emergent herbicides need to be applied before crabgrass germinates, which is when the soil temperature is 55-60 degrees Fahrenheit. This typically occurs toward the end of April. Applying this chemical too soon may cause the chemical to stop working earlier in the season when crabgrass may still be germinating. In this case an additional application may be necessary later in the spring, so it is best to wait until the correct time to only have to apply this one time per season. Broadleaf weeds, such as dandelions, clover, and ground ivy should be controlled in the fall for best control but can be managed in the spring with 2,4-D products.

Fertilizing turf can be done up to 4 times per growing season. Apply fertilizers at a rate of 1 pound of nitrogen per 1,000 square feet for each application. A good trick for remembering when to apply fertilizers is to fertilize with the holidays: Arbor Day, Memorial Day, Labor Day, and Halloween.

Mower Collage

We are now getting to the time of year when we will have to start mowing our lawns. Prepare your lawn mower for the season before you start mowing. Start by sharpening the blades. Dull mowing blades can cause tearing to occur on the grass blades rather than a smooth cut. These tears can lead to more insect and disease problems. Change the oil in your lawn mower, if you didn’t do that in the fall. Check your spark plugs and tire pressure. Finally, make sure you clean under the deck for any grass that may still be stuck under there from last season. You can start mowing as soon as the grass starts growing. Remember to mow at a height of 2.5-3.5 inches and only cut off 1/3 of the grass blade each time you mow.

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.

Spring Lawncare

2011-10-27 10.05.27Each year in the spring, we tend to get very excited to be able to get back outside and work in our lawns and gardens. However, this is still fairly early in the year to do much work in our yards. This article was written to prepare you for when the best time is to begin lawncare activities in the spring.

Overseeding our lawns can take place between April 1 and April 30 for the cool season turfgrasses, such as Kentucky bluegrass and turf-type tall fescue. If you are planting a new warm season lawn or are adding plugs to thicken it up, you should wait until late May through June to do that. The warm season grasses would be either Buffalograss or Zoysiagrass. These would be the four best turfgrasses to use in our lawns in Southeast Nebraska.

When purchasing grass seed, watch for the following important statements on the seed bag:

  • Purchase weed free seed, 0.3% or less weed seed in the package
  • No noxious weeds found in the seed mixture
  • Avoid purchasing lawn seed that is advertised in the Sunday newspaper, as those are not usually good seed choices and are not suited well for our area
  • Avoid purchasing lawn seed that contains annual ryegrass as that is more of a weed species

The best seed choices are either:

  • 100% of turf-type tall fescue
  • Kentucky bluegrass
  • Buffalograss
  • A mixture of tall fescue and bluegrass

Mowing your lawn should begin as your lawn begins to grow again. We should mow our lawns to a height of at least 2” for Kentucky bluegrass and 2.5-3” for tall fescue. So, you can wait until the lawn gets to at least 3 inches before beginning the mowing routine in the spring. Remember, only mow off 1/3 of the grass each time that you mow. The lawn clippings may be left on the lawn or bagged and removed from the lawn, at your own discretion. If you return the clippings back to the turf, it will add up to 1 pound of nitrogen per 1,000 square feet over the course of the growing season. This can account to one fertilizer application for your lawn over the growing season.  Below is a picture of the 3 types of lawn mowers you can purchase.

Mower Collage

As for the fertilization, this should also wait until later in the spring. It is recommended to add 1.0 pound of fertilizer per 1,000 square feet between April 20th and May 10th. This fertilization should be done with a slow release fertilizer of your choosing. Fertilization of Kentucky bluegrass can be applied 4 more times throughout the growing season. To make this easier to remember, fertilizer treatments should be done on Arbor Day, Memorial Day, Labor Day, and Halloween. As for tall fescue lawns, these only need to be fertilized two times a year, in the early spring and late fall. We should avoid fertilization during the hot summer months to avoid possibly burning the grass blades. The spring fertilization can be done in combination with a pre-emergent herbicide that will combat crabgrass, foxtail, sandburs and goosegrass. Do not use crabgrass pre-emergent herbicides if you have overseeded in the spring until you have mowed your new seedlings at least 3 times. Dandelion and other winter annual weeds can be treated in combination with the Labor Day fertilizer treatment for best control.

Fertilizer Spreader, Photo from Acreage.unl.edu