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cle63
09-03-2006, 05:13 PM
Hi. Similar to the superrman77 post, my lawn is a mess. Lots of crab grass and other weeds, and so I'm thinking that I should just till everything and seed a new lawn. I'm hoping to do this this fall and am assuming that late September is the time. I live in central Ohio. It's crossed my mind that I should just Round-Up what's there now and wait for that to die, but I'm concerned that this will hinder growth of the seeds that I plant. Any suggestions? Does the chemical in Round-UP dissipate, and if so, how long should I wait to till and then seed? An added wrinkle is that every spring we start to get snowbells and a similar plant with blue flowers (bluebells?) that take over the yard for a couple weeks. Any help is appreciated.
T

lawnmaniac883
09-03-2006, 09:48 PM
Spray RoundUp at the recommended rate of 6oz/gallon of water and wait one week. Go back over the area and spot treat with more round up the areas that are not completely dead.

Two or Three weeks later, till the soil to atleast 6 inches and then go over and grade the area with a rake. Let the soil sit for 1 week to allow it to settle then either have someone hydroseed / renovate the area or try and spread seed/rake in.

jeffinsgf
09-04-2006, 06:17 PM
If your grade is good, don't till just to till. You will only bring more weed seeds to the surface. Glysophate (RoundUp) only kills green, growing plants that it touches while wet. I think the package says to wait a week, but theoretically, even that is not necessary. I would kill, core aerate and then use a slice seeder, if the grade is already where you want it. If you want to regrade, then kill, till, grade, roll, rake, seed, roll and water, water, water.

LarryF
09-05-2006, 08:09 AM
I would kill, core aerate and then use a slice seeder, if the grade is already where you want it. If you want to regrade, then kill, till, grade, roll, rake, seed, roll and water, water, water.

What about the billions of seeds that had been dropped by the weeds you've now killed with the Roundup? Don't you also have to do something to get rid of them? If not, won't they germinate along with the newly applied grass seed, and you'll have to do this all over again in a year or two?

jeffinsgf
09-05-2006, 01:33 PM
What about the billions of seeds that had been dropped by the weeds you've now killed with the Roundup? Don't you also have to do something to get rid of them? If not, won't they germinate along with the newly applied grass seed, and you'll have to do this all over again in a year or two?


That assumes that the weeds are in a ripe seed head stage. Also, many of the weeds that you would be dealing with are not as likely to grow well in the fall, while cool season grasses will. There's no panacea. It is likely that getting the weeds out will be a multi year project, but tilling won't change that and might make it worse. Unless you are adding large amounts of soil amendment (compost and/or sand) or changing the grade, tilling seems like a lot of work for little gain to me.

LarryF
09-05-2006, 02:47 PM
That assumes that the weeds are in a ripe seed head stage. Also, many of the weeds that you would be dealing with are not as likely to grow well in the fall, while cool season grasses will. There's no panacea. It is likely that getting the weeds out will be a multi year project, but tilling won't change that and might make it worse. Unless you are adding large amounts of soil amendment (compost and/or sand) or changing the grade, tilling seems like a lot of work for little gain to me.

Thanks for responding Jeff. I wasn't thinking of tilling the ground, but I do wonder about using a preemergence herbicide such as Lesco's Snapshot 2.5TG for annual weeds. That stuff is expensive and I'd rather not, but it seems to me that the weed seed could stay in the soil until next summer and start to germinate then. I admit that I don't really have much of a feeling for the "ripe seed head stage" that you refer to, but it seems to me they'll get to that stage evenutally unless something is done to prevent it from happening. I also don't know if the herbicide I mentioned would impact the grass seed I would be planting should I use it after killing the weeds with Roundup. In my case, my weeds are mostly crabgrass, veronic and I think carpetweed. And if it could impact the new grass seed, how long should I wait before seeding the grass?

NNL&LS
09-05-2006, 09:05 PM
How large is your lawn? have you considered roundup, then sod?

jeffinsgf
09-06-2006, 07:57 AM
Thanks for responding Jeff. I wasn't thinking of tilling the ground, but I do wonder about using a preemergence herbicide such as Lesco's Snapshot 2.5TG for annual weeds. That stuff is expensive and I'd rather not, but it seems to me that the weed seed could stay in the soil until next summer and start to germinate then. I admit that I don't really have much of a feeling for the "ripe seed head stage" that you refer to, but it seems to me they'll get to that stage evenutally unless something is done to prevent it from happening. I also don't know if the herbicide I mentioned would impact the grass seed I would be planting should I use it after killing the weeds with Roundup. In my case, my weeds are mostly crabgrass, veronic and I think carpetweed. And if it could impact the new grass seed, how long should I wait before seeding the grass?


The packaging should tell you how long to wait. You might be able to get that from Lesco's website, too. Don't worry about the crabgrass you have now. It will be dead after the first frost. Seed now, get the grass established, then use preemergent in the early Spring. My yard was filled with crabgrass last year. I used a preemergent the first week of March and didn't see any crabgrass all year. The way to keep weeds from setting seed is to keep their heads cut off. That's a pain when they grow faster than the grass -- you have to mow based on the weeds instead of the grass, but that is the surest and cheapest way to kill weeds -- don't let them grow. Crabgrass can be the exception to that, because it will duck and throw a seedhead at 1-1/2 inches if it has to.

TforTexas
09-06-2006, 09:06 AM
Snapshot is not labeled for turfgrass areas. If you want to use a preemergant along with cool season seeding you can use Drive 75. I will offer pretty good pre emergant control plus post emergant on some species (Round up will have already taken care of that.) Seeding in the fall you will mostly germinate broadleaf weeds which can be taken care of once the new seed is up and mowed 4-5 times. Dimension, Barricadef or Pendimethalin in the spring will give you good control of the grassy weed. Remember starting over from scratch may cause you to have a year of "growing pains". Getting the new grass established and knocking back the new weed crop.

LarryF
09-06-2006, 11:13 AM
Snapshot is not labeled for turfgrass areas. If you want to use a preemergant along with cool season seeding you can use Drive 75. I will offer pretty good pre emergant control plus post emergant on some species (Round up will have already taken care of that.) Seeding in the fall you will mostly germinate broadleaf weeds which can be taken care of once the new seed is up and mowed 4-5 times. Dimension, Barricadef or Pendimethalin in the spring will give you good control of the grassy weed. Remember starting over from scratch may cause you to have a year of "growing pains". Getting the new grass established and knocking back the new weed crop.

Thanks T, I now realize you are absolutely right about the Snapshot, and I hope I didn't steer anyone in the wrong direction by mentioning it. I had used Roundup and then Snapshot with good success on a pretty large (~5000 sq ft) mulched area where weeds had taken over the area, so the Snapshot label was in my mind. But looking again I see that one definitely doesn't want to use it on a lawn. Nonetheless, it sound like you are in agreement with my point that just killing this year's weeds with Roundup isn't going to really solve much unless you also do something to eliminate the weed seed that has already dropped into the soil; otherwise, the weeds will be back next year. I think your advice is good and I'm pretty sure I'll be taking it.

In regard to the sod suggestion by NNL&LS, I haven't considered it and I don't think I will. I have about an acre of grass, but only about 15 percent of that has a weed problem. I think I can resolve it without resorting to having sod placed, and looking at the lawns of neighbors who have done that a couple of years back, they seem to now have lots of weeds too. I'm sure there are good reasons for using sod, but I'd skeptical that weed control is one of the predominant ones. But thanks for the suggestion, anyway.

turf_toes
09-28-2006, 01:41 PM
I've done this project now two straight years (last year in front -- this year in half the back yard).

You do NOT need to till (you'll just disturb the soil and bring more weed seeds up where they'll get sunlight and grow). Leave the dead grass in place.

In fact, the dead grass will act to help prevent the seed from washing away in the event of a storm. The roots underground will degrade naturally and provide organic material to your soil.

Here's what I did.

Kill the old lawn with roundup. Since it's getting late in the season for overseeding, you can seed one day after hitting the old lawn with roundup. I did so this year and the new seed has germinated and looks great. Roundup quickly dissapates in your soil.

Rent a slit seeder or powerseeder from Home Depot. That will cost you $80 for the day.

Get the best seed you can afford. I'm a Kentucky bluegrass fan. But even if you prefer Turf-type tall fescue, this advice still applies. Go to http://www.ntep.org to research which grass seed did best in the trials in your area.

The elite Kentucky Bluegrasses like Midnight are expensive, but worth it. Not all grass seed is alike. Read the label. If it contains more than ZERO weed seed content, do NOT buy it.

There are about 1.6 million seeds in a single pound of Kentucky Bluegrass. At the recommended rate of application of 4 pounds per thousand square feet, you are putting down approximately 6.4 million seeds per thousand square feet.

If the seed you buy contains even 0.2 percent weed seed content, you are putting down about 128,000 weed seeds in 1,000 square feet.

You can see where this is going. The seed sold at the big box stores tend to have weed seed content. Avoid it at all cost. You get what you pay for.

There are plenty of places online that will guarantee zero percent weed seed.

I purchase my seed from a place in Oregon called Roseland Agri-seed. This is the same company that used to own Turf-seed.com. They actually grow, research and sell seed to commercial suppliers like Scotts, etc. (They're the folks who originally (along with Rutgers University) developed Midnight Kentucky Bluegrass.

The seed from Roseland is guaranteed by the state of Oregon to contain zero weed seed. You may still get some weeds growing in your yard, but that will mostly be from seeds already in your soil or blown in by the wind.

After you seed with the slit seeder/power seeder, water it three times a day for about 10 minutes in each location. You need to keep the seed bed moist. If you don't do that, the percentage of seeds germinating will decrease. (You can buy hose bib timers at Home depot for $40 so you can water even while you're at work).

My kentucky bluegrass started germinating after two weeks (the lable claims it is normally 21 days to a month).

Good luck.

turf_toes
09-28-2006, 01:41 PM
I've done this project now two straight years (last year in front -- this year in half the back yard).

You do NOT need to till (you'll just disturb the soil and bring more weed seeds up where they'll get sunlight and grow). Leave the dead grass in place.

In fact, the dead grass will act to help prevent the seed from washing away in the event of a storm. The roots underground will degrade naturally and provide organic material to your soil.

Here's what I did.

Kill the old lawn with roundup. Since it's getting late in the season for overseeding, you can seed one day after hitting the old lawn with roundup. I did so this year and the new seed has germinated and looks great. Roundup quickly dissapates in your soil.

Rent a slit seeder or powerseeder from Home Depot. That will cost you $80 for the day.

Get the best seed you can afford. I'm a Kentucky bluegrass fan. But even if you prefer Turf-type tall fescue, this advice still applies. Go to http://www.ntep.org to research which grass seed did best in the trials in your area.

The elite Kentucky Bluegrasses like Midnight are expensive, but worth it. Not all grass seed is alike. Read the label. If it contains more than ZERO weed seed content, do NOT buy it.

There are about 1.6 million seeds in a single pound of Kentucky Bluegrass. At the recommended rate of application of 4 pounds per thousand square feet, you are putting down approximately 6.4 million seeds per thousand square feet.

If the seed you buy contains even 0.2 percent weed seed content, you are putting down about 128,000 weed seeds in 1,000 square feet.

You can see where this is going. The seed sold at the big box stores tend to have weed seed content. Avoid it at all cost. You get what you pay for.

There are plenty of places online that will guarantee zero percent weed seed.

I purchase my seed from a place in Oregon called Roseland Agri-seed. This is the same company that used to own Turf-seed.com. They actually grow, research and sell seed to commercial suppliers like Scotts, etc. (They're the folks who originally (along with Rutgers University) developed Midnight Kentucky Bluegrass.

The seed from Roseland is guaranteed by the state of Oregon to contain zero weed seed. You may still get some weeds growing in your yard, but that will mostly be from seeds already in your soil or blown in by the wind.

After you seed with the slit seeder/power seeder, water it three times a day for about 10 minutes in each location. You need to keep the seed bed moist. If you don't do that, the percentage of seeds germinating will decrease. (You can buy hose bib timers at Home depot for $40 so you can water even while you're at work).

My kentucky bluegrass started germinating after two weeks (the lable claims it is normally 21 days to a month).

Good luck.