Replacing the weeds in my lawn with grass this fall.

August 23, 2010 11:04 PM

Replacing the weeds in my lawn with grass this fall. Best way to do it?

I recently bought a house. The backyard is pretty big (and unshaded) - about 4500 square feet. The backyard is pretty much all weeds (clovers, crabgrass) which looks okay when mowed, but looks pretty bad after growing for a week.

What's the best way to replace my lawn with grass? People have suggested bags of 'seed and feed' at Home Depot - to kill off the weeds and drop in new grass seed.

I'd like to start it as soon as I can. I live in the Maryland suburbs, just a few blocks outside of DC. My soil is pretty moist and clay-y.

posted by waylaid to Home & Garden (12 answers total)

Is foregoing grass altogether an option you'd consider? I had read about clover lawns before and how they're much easier and more eco-friendly to maintain than grass/sod, but I had never actually seen one until a few years ago. It was gorgeous--interesting to look at, lush, and green, and had a secret garden type of feel to it. It was a smallish area, though, so it might not work as well for a backyard like yours. If I ever have a lawn, I intend to cover it in clover.

Here's a site all about clover lawns I just found with a google search (so I can't vouch for its content).
posted by phunniemee at 11:21 PM on August 23, 2010 [1 favorite]

I went through the same thing to my 200 sq ft backyard (I know, tiny) in Utah. I spent a couple hours pulling all the weeds that weren't tiny. Believe me, it pays to take the extra time to completely pull everything you can. Then I just applied a concentrated weed killer. Not a vegetation killer, but just a weed killer. After a few days (when the remaining weeds were browning), I raked them all up with a garden rake. That helped to corral all the rocks that were in the soil, too.
After dumping the rocky, weedy junk from my yard, I went and bought enough topsoil to cover almost 3 inches over the existing soil. The reason for this is that the best way to naturally prevent weeds from popping up (i.e., all those weeds I pulled that still had plenty of roots still in the ground because I wasn't careful about getting all the roots) is to keep your soil as healthy as possible. Some people even go so far as to sprinkle sugar or a sugar/water solution over their lawns to enrich the soil. After that I rented a cheap roller (the kind you fill with water and then push around what ever you want to compact) and compacted the soil. Then I laid the sod. That was the easiest part. After the sod was laid I rolled the entire area again. For the next three days it was important to keep the lawn soaked but not swampy. After that I did a thorough watering/soaking every other day, and after a month a moderate watering 3 times a week. I also didn't mow for a couple months.
Sure enough, my lawn is gorgeous, lush, requires little watering, and never gets weeds. Of course, my whole method would have to be scaled up quite a bit for your lawn, and I'd suggest installing a large patio or some fringe xeriscaping or a garden so that the task of sodding or seeding isn't so huge. I did mine in the mid-fall, so you should be good to go (in Utah we have harsh, early winters and my lawn survived wonderfully).
posted by Detuned Radio at 12:17 AM on August 24, 2010

Check this video and go to 1:27 where he talks about lawns.
posted by leigh1 at 4:01 AM on August 24, 2010

As with anything lawn related, I'd consult Jerry Baker's book.
posted by sanka at 4:30 AM on August 24, 2010 [1 favorite]

I suggest that you wait until spring. Nothing is going to grow over the winter, and the best time to seed is probably in March or April.
posted by valkyryn at 5:15 AM on August 24, 2010

You should go to a local garden center and ask them. They can get you a location appropriate seed mix, and give you recommendations on what to do about your existing lawn. And if you're where your profile says you are, the best time to seed your lawn is right now.
posted by electroboy at 6:28 AM on August 24, 2010

Everything I have read recommended if you are over-seeding to mow super short in august or September, then rake the yard to break up the thatch a bit. when you mow it short, bagging would help the seeding process. then seed, water, and don't mow until it gets pretty long.
posted by Amby72 at 6:30 AM on August 24, 2010

The soil around here is indeed quite laden with clay. Best advice? Give up on fixing the current mess and put sod down. By the time you eliminate the existing problems you'll likely have spent more time and money that sod would have cost. That and improper fertilization and other treatments end up as run-off only contribute to ruining the waterways (like the Chesapeake). Talk to a local sod farm about it.

And if you go that route, be serious about keeping it properly watered. Get a timer and rig up some sprinkers. There are some really nice ones out now that are quite adjustable. Best thing I've ever done for me landscaping was to go with water timers. You don't have to go permanent in-ground either.
posted by wkearney99 at 7:27 AM on August 24, 2010

Can't find the link right now, but corn gluten us a good pet/child safe way to get rid of crabgrass. Crabgrass doesn't over-winter. It's killed off by freezing temps and doesn't regrow (it just gets reseeded from birds, the wind, seeds on the ground? etc.)

this was a particularly good year for crabgrass (if you're crabgrass). You can use corn gluten in the fall. But we've decided to let it die off and then launch our first offensive in the spring, to be followed by fall application 2011.

Of course, I live where there is winter.
posted by vitabellosi at 8:16 AM on August 24, 2010

I've tried all sorts of half-steps with my quackgrass and crabgrass. (And if the lawn is very weedy, I'm willing to bet you actually have a lot quackgrass as well, because that's the species that really invades lawns with the virulence of the black plague combined with the ferociousness of a wounded bear.) Half-measures will not work. (Also, weed n' feed mixes are banned in many jurisdictions due to the high fertilizer content which negatively affects run-off systems and the water quality in rivers and lakes.)

Utter and complete annihilation via a broad spectrum herbicide (i.e. RoundUp) or digging a foot or more into the soil and replacing it with clean soil are the only effective methods, IME. Then keep a tarp or landscape fabric over it during the winter and replace with either sod, or better yet, a drought-resistant, native grass mix like eco-lawn. (Or, if you're me, a mess paving stones (no mowing required!) over half of the lawn and a fire-pit so you can spend evenings getting in touch with your inner cave-person by roasting huge chunks of meat over an open fire. Whee!)
posted by Kurichina at 9:01 AM on August 24, 2010

I've got a patch of (former) lawn that was a pain in the ass to mow, so I dug the grass out and replaced it with low growing sedum, periwinkle, and creeping thyme. Other than pulling the occasional weed, zero maintenance. I like that.
posted by ducktape at 11:00 AM on August 24, 2010

Fall is a great time to plant. I would not use weed and feed type week killers. They typically are 2,4-D a particularly toxic brew. It kills weeds and leaves grass. If you are going for a total reseed then you can use much less toxic methods. The greenest method is to cover the current weeds and grass with newspaper or black plastic and weight that down with soil or something until everything underneath is killed. This is time consuming and will take at least a month but it requires no chemicals. Round-up is a broad spectrum herbicide which will kill everything, the weeds, the grass etc. Not so much you. It is fairly benign as these things go but you can find research linking it to some health problems. After the weeds are dead some tilling and perhaps even more topsoil will help start new seed. Water before you till so that the soil is not too hard. You can rent a tiller. That would also be a good time to install an underground sprinkler system if you want to invest the cash. When the field is ready add seed, fertilizer and something to keep it moist. Straw is cheaper but the cellulose bits sold for this work really well. For a lot your size I would go with straw. Water several times a day. If you do not go with an underground system buy a bunch of hoses, sprinklers and timers so that it will get watered even if you forget. For Maryland I would think the mid to late September would be the right time to do this but I would ask at your local garden center.

I am a big fan of a clover lawn as it reduces the need to fertilize. You can have a great lawn with an all organic program and clover helps here. One downside if you have kids, clover stains are much hard to get out of clothes than regular grass stains. Also, any application of 2, 4-D kills off the clover, but then you should avoid that stuff if possible. Maybe to spot treat a few weeds here and there, but not as a broadcast on the whole lawn.
posted by caddis at 1:48 PM on August 24, 2010