Knowing where you are and the type of grass you have may help. How big of an area is it? Core aeration followed spreading compost may be an option.

tj

I'm in upstate NY. The yard is 2/3 acre, but the compacted areas are probably a fifth of that or less. It's currently just a mix of cold season grass mixes, with lots of weeds. I don't think machine aeration is a great option, because there are mature trees nearby. I've tried manual core aeration and it takes forever. I've even tried focusing on a small patch with intense core aeration and then added some grass seed, but got very little germination. Edit: I should probably also add that I am in a rural area with a hay field behind my house, so there are no HOA regulations I must follow regarding my lawn.

Six on one, half dozen on the other. Will it help? Sure, over time. The other option is to get a soil test and get it read. There's another forum that reads them, we used to do it here but don't any longer.

Compacted soils can (and often are) caused by a misbalance of calcium, magnesium, and other elements.

As you noted, mechanical aeration is...well, often not a great option for many reasons. It doesn't reach very deeply, the soil just re-compacts because the core causes aren't addressed, and so on.

Another option is...well, soap. But David has become the biggest advocate of that and will be along shortly. :-)

Biggest advocate? or are you feeling lazy today? Well I suppose I am an advocate, but only because I was so shocked that it worked so well. Even my wife, who thinks my lawn care ideas are a little scary at times, sees the benefit and carries a bottle of soap into the garden with her if she finds some hard soil. I had developed a method to soften hard soil, but it took weeks for just a small area unless you invested heavily in soaker hoses. I had been reading morph and others raving about using a specially formulated concoction of soap powders that morph came up with. The problem with that was I didn't want a lifetime supply of powders. So I tried doing it with shampoo, baby shampoo to be specific. It worked fantastically over a large area, quickly, and seemingly permanently. After spraying with the shampoo (3 ounces per 1,000 square feet), then every time it rained my soil became so soft it was difficult to walk on. It was like walking on fluffy beach sand. It firms up again as the soil dries out.

Apply like this. Use a hose end sprayer. If you have 3,000 square feet to spray, pour 9 ounces of shampoo into the sprayer. Fill it the rest of the way with water and spray it at any setting to evenly cover the entire area. It doesn't matter if you miss spot or go heavy. You can redo it any time. Morph has tried to overdo it by applying far too much of his soap and never encountered any damage from too much soap. Give it about 3 weeks and you should see a dramatic improvement. One of the guys on that other forum he mentioned had a limb fall off a tree and embed itself 24 inches deep into his soap-softened soil.

How does it work? Tons of research has been done using surfactants like Cascade Plus (not the dishwasher soap) on golf courses. Those are focusing on a slightly different aspect of the wetting issue, but it is related. My theory is that the shampoo allows water to penetrate much deeper into the soil which changes the ecosphere down there. The moisture keeps the soil at a more constant temperature and humidity. This is the perfect environment for the beneficial fungi which live in the soil. Those guys are the ones softening the soil for you. You don't have to do anything as long as you are keeping them fed (organic fertilizer) and watered.

You can find that other forum by searching for his name and mine in the same search. Find the forum where they do the soil tests and read how to get started. Logan Labsis the place to get the soil tested. Get the Standard $25 test. As morph mentioned, hard soil is often not clay but an imbalance in salts. If you treat for clay, the salt problem will keep the soil hard. If you treat for salts, and it was clay, then you haven't fixed it either. Get the soil tested and read.

You didn't mention timing for when you did what you did, so I'm going to give you a general calendar for lawn care.

NOW: apply a preemergent herbicide to take care of weeds that are about to sprout. The preemergents last about 3 months, so the benefit should take you through awakening in late March or early April. Also now, do not feel the pressure to fertilize the lawn. It will not need fertilizer until Memorial Day in late May. You'll see all the feed stores advertising fertilizer saying "NOW IS THE TIME." Now is not the time. Memorial Day is the time.

Mid April: Spot spray weeds with something like Weed-b-Gon or Weed-b-Gon Chickweed, Clover, and Oxalis Killer. Those are different products. The WBG CCO is a stronger product.

Late May: fertilize with your choice. My choice is organics from the feed store. I like alfalfa pellets (rabbit chow) or corn meal. In your area you'll find soybean meal much cheaper than I can get it here. Soybean meal is a better fertilizer, so get that in a 50-pound bag. Apply at a rate of 15 pounds per 1,000 square feet. You cannot over apply soybean meal either. If you accidentally double it - fine. If you spill the bag on the ground, use a rake to spread it out or a leaf blower to keep from smothering the grass. No harm done, though. That spot would become the greenest spot in the yard in about 3 weeks.

Mid August: Overseed the grasses of your choice. I would stick with normal lawn grasses like turf type tall fescue, rye, and/or Kentucky bluegrass.

Labor Day: fertilize again

Mid September: Spot spray the weeds only if you feel the need.

Thanksgiving (or there abouts): Winterize the lawn after it stops growing but before you get a hard frost. The roots will still be working underground to absorb the nitrogen and hold it for spring 2022 when the grass awakens. Use a high N like 45-0-0 fast release. Basically urea.

Also what is your watering schedule. All I've said here sort of depends on regular watering. If you don't water and rely on rain to water the grass, then you can just forget all this and accept the weeds as a result.

Lazy. Remember, we just got 30" of snow with another 4-8" coming tonight into tomorrow. I'm painting snow scenes. With the dried blood coming from my blisters.

I didn't realize that soil chemistry was a factor in compaction. I did a home test kit in part of the yard last year and it was in the "normal" ranges. But, my soil characteristics (including compaction) seem pretty patchy so it would probably make sense to test other areas, and to perhaps send some off to the pros. I hadn't considered soap for this purpose - though I've certainly heard of other things it can do for yard and gardens! I guess the thing that attracted me to trying cereal rye is that it seems to require minimal effort from me (yep, laziness) and if it worked, could reach deeper than my little manual core aerator. Maybe I can combine it with some of these other approaches.

Soil chem plays an amazing part in soil compaction...if it plays any role at all. It's kind of one or the other. If calcium is low but magnesium normal, it's an extreme role. If calcium is normal and magnesium low or normal, practically nothing. If magnesium is high, quite a lot again.

Home tests are...well, I'm sure you did it according to the package, it's the tests that are terrible. I'd trust the worst soil lab before I'd trust any home test (and I don't even trust the average soil lab).

Soap is amazing stuff (I include detergents and other surfactants here as they'll all work the same in this instance and some others). I adore soap. I make soap. I fully recommend its use here.

Adding the rye grain will break up soils--indirectly--by encouraging fungal development, bacterial growth, and worms, all of which will definitely work to break the soils. It does take time, on the order of years, but it's a good long-term solution once the chemistry is balanced.

And your lawn will love the feeding from the rye grain as well. :-)

We can help you to a low hassle lawn that looks great. It will require regular (not daily) watering when it is not raining, a chemical herbicide used only on the weeds, and regular or organic fertilizer. Morph and I both use only organic fertilizers and can get you going there. Our approach is low hassle, because it is hard to make a mistake with the organic fertilizer or the soap softening mix. Oh you will also have to mow at your mower's highest setting every week or so.

Annual rye grass works much better than cereal rye grass for breaking through layers of compacted soil. Annual rye is also in many seed mixes and also does better in denser clay soil. No I didn't know this until now after reading this article.

annual vs cereal rye grass

If the compacted soil goes down more then 3 or 4 inches Core aeration won't help you and what you're dealing with is hardpan soil and can go down a foot or more. If you don't want to wait years trying to get a rye to breakup this hardpan you can do it with a chisel plow or subsoiler.

If you have access to a larger size garden tractor with a 3 point or a smaller tractor a chisel plow will get down and breakup that hardpan soil. I made a subsoiler to use on my 3 point to get down 16" in my gardens and works great.

Thanks, Kevin! But we're actually talking about using the grain applied to the soil of an existing lawn here.

But yes, I'd agree that if you were going to till it in, use the annual rye! It's cheaper, not likely to come back, and works great as an organic addition to the soil.