Hello SigForum! I bought a new home (new construction) last summer and the backyard was a clay mud pit. I rented a tiller a few weeks ago and got a bunch of rocks, cement debris and other construction debris out of the ground. We leveled the soil as much as possible but it's thick clay.

I was going to have topsoil delivered this weekend but now I'm reading that I should kill whatever weeds may be left over. When I tilled the yard, there was a lot of weeds which we pulled as much as possible. I guess what I'm asking is what should I use to treat the base layer and how long should I wait before laying the topsoil? Should I lay the topsoil and treat with weed killer?

How long after we treat the lawn with weed killer do we wait before laying seed? Should I postpone the topsoil?

I live outside of Portland, OR.

Thanks in advance.

Tony.

First, get a soil sample to see where you are at on the Ph scale. Amend the clay and then add your top soil and test aagain as the top soil could be out of spec to grow grass.

After you are happy with the soil tests (the local Extension Service should do it for free, they do it for free in Arkansas)take a serious look at Hydroseeding the yard. I do this commercially as a retirement job and usually charge 1 1/2 cents per square foot. This includes a fertilizer, grass seed ( Rye for quick green-up and then Bermuda or other choice), a green dye mixed in and a chopped, sterilized straw product to protect the seed from birds and finally a natural glue product that holds everything in place. You can grow grass on a rock with this mixture.

Good Luck!

When I lived in the Upper Midwest, I bought my first home and it came w/o landscaping or a lawn. I decided to invest a little sweat equity and DIY.

First thing I did was to spray everything down with Glyphosphate (generic Round-up) to kill everything. Then I worked with a local nursery who did free landscape design if you bought the plants from them. They knew my Mom and Dad for decades so took my word that I'd be back to buy plants.

The sprinkler system was a real PITA as there was two gravel pits within a mile. About every 18" the rental trencher would hit a 5" diameter rock and buck like it was a bull in the rodeo. About once every 2 hours would hit a rock at least 12" in diameter. It took 2 Saturdays to trench everything, put in all of the pipe, and install the sprinklers.

The weeds started to sprout so I applied another round of Glyphosphate.

I proceeded to install all of the landscape borders, weed barrier, and countless yards of rock. Then, went back to the nursery, bought the plants, and planted everything.

I then proceeded to get the worst sunburn of my life raking the rocks out of the dirt with a landscaping rake. I threw in the towel and called the same hydroseeding guy my Dad had used a few years earlier. First words out his mouth were that neighborhood has a lot of clay and rocks so the first step would be putting on a 5' wide landscape rake on the back of his 40 horsepower Kubota. It loosened up the soil and got out a pile of rocks about the size of a Lazyboy recliner, and the best part is that it took all of 30 minutes.

His partner's truck was towing the hydroseeding trailer, and they sprayed down my bare lawn with Kentucky Blue Grass and Fescue mix in short order. Between the hydroseeding and my sprinkler system my lawn looked as good as sodded lawns by the end of the 2nd summer.

Are you going to install a sprinkler system? If you are going to have a nice decent size lawn you need one, even in Pdx imho. I would not do a bunch of treatment (weedkiller) before seeding. Preferably hydroseeding. I am not a fan of sod. I know many are. And yes amending the soil sounds like a good idea. No need to go nuts though. Good luck.

We have a local outfit around here that I used.

My ground sucks. About 70% rock and 30% dead dirt (not "soil" by any stretch). After leveling everything out with the box blade and installing a sprinkler system, I had them come in. They blew on a mix of quality soil, compost, and seed roughly 6" deep and perfectly level. The lawn came in beautifully.

Check around your area for landscaping outfits that do the same thing would be my recommendation. They are fairly spendy, but so worth it when you consider what a pain in the ass that kind of work is to do yourself.

Check with these people. I wont use any other seed or sod

https://www.jbinstantlawn.net/resources/display/seed

JB Instant Lawn, Inc
5289 Bluegrass Lane NE
Silverton OR 97381

503-581-7823

The reality of the situation is that there is no quick solution.
Anything you put down to kill weeds prior to their emergence will also kill grass seed.
You can hit roundup and then sow grass seed. Allow it to get up and growing and then hit it with a broad leaf herbicide. Reseed in the fall to fill in even better. Also hit with good nitrogen fertilizer.
Next Spring hit with a good preemergent to control weeds and crab grass.
There is no quicker way to do it other than sod.

I am by no means an expert. I've only bought one new house in my life. That was 8 years ago and we made enough "mistakes" that I was shocked. We toughed it out. The builder was no help as in leaving a terrible mix of rocks the size of cigarette packs and some lousy clay. He did the "un" favor of destroying some really good zoysia grass.

I hired a friend who needed some work. He did a fine job of scraping a bunch of the surface rocks and depositing them in a dumpster. I consider that a return of the favor to the builder.

Then I made the mistake of buying cheap topsoil. Not the good forest floor loam, but instead river mud. I tried to go cheap and only bought the amount needed to cover the mess by a few inches. Then we seeded that and didn't use much straw. All kinds of seed float downstream in a river. It all germinates faster than grass and with less moisture.

So what I should have done is pay my guy to haul out even more of the clay and rocks. Then we should have run from the river bottom muck. It was admittedly rich soil, but over run with junk plants. Its looking nice now. We weathered most of the last 8 years fighting it. I have no idea how we got low spots. They looked fine the first few years. I attacked it by using bags of topsoil when on sale at home despot.

It will come as no surprise that fertilizer is going to be your friend. Just keep using it in the recommended dosage. Then water is your friend, too. Water the crap out of it, or try seeding when the daily temps get down to maybe 55 degrees as the daily low.

But I'm proof that you can do most of the stuff wrong and still have a nice lawn if you're willing to fight it for years.

I have a terrible backyard and just cannot get grass to grow between the rocks, runoff, and just bad soil. This is a timely post for me as I learned a ton of new stuff and may just have to go the hydroseeding route after getting the ground tested. Thanks to all and sorry for the thread drift.

Your county extension agent is your best resource. Growing grass is very region-specific, especially if you want picture-perfect golf course fantasy turf. For example, the seed mix that is most appropriate for your area and soil will not be right even 100 miles away.

+1 on the hydroseeding, this method of application gives very reliable results.

++1 on soil improvement. Heavy clays are not what grass likes. Spend $10 on soil improvement for every $1 spent on seed, fertilizer, etc.

If you are very worried about existing weed seeds, it is possible to sterilize the soil (before improvement). A licensed contractor will tent your yard, and introduce a gas mixture under the tarp that kills everything. This leaves no significant residue. This is a drastic step, and is rarely required (also dangerous). Almost always, dealing with weeds after lawn establishment is sufficient. If your turf is healthy enough, weeds will be crowded out.

These are some of the lessons I learned in a previous life, 20 years in the non-chemical turf care industry, but what do I know, my lawn looks like shit!

Great info! We're doing this on the cheap and we're patient. I don't mind taking time to do it. We cancelled the topsoil for Saturday and will treat the existing soil with the glyphosphate.

How thick should our topsoil be? I was thinking 2" of topsoil which should allow us to smooth out the yard. Right now it's a little bumpy but the soil is too thick to break up being the time of year. It hardens too much in the summer for a tiller.

My backyard is about 30'x30'plot and slopes down about 3' to 4'in that distance.

This is who we were going to get topsoil from. We were going to use their "Landscaper's Choice Soil blend which should allow water drainage considering the slope of my yard.
http://www.bestbuyintown.biz/p...s-services/top-soil/

Also, my backyard won't get much direct sunlight throughout the year so we need a blend of grass that will stay thick in shade and can handle the amount of rain we get from October through May.

Tony.

We have a large yard - 2.5 acres and we keep it looking like a park by using the right fertilizer and right weed control.

We started by installing a multi-zone sprinkler system followed by hydro-turfing most of it when the house was new - this is a truly great product and we had a good yard in year 1.

A couple of years ago we added Rachio sprinkler controllers. These are smart controllers that I can manage though my iphone. We have 24 zones total with about 175 sprinkler heads and 6 drip zones.

Luckily we don't have any clay. I would want as much quality top soil as possible in your case.

By all means research and then spend the money to get very high quality seed. I'm talking about not only weed free and high germination, but a cultivar that performs well in drought, disease resistance, and color retention.

There is a wide gulf between contractor grade, and premium grade turf grass. If you have access to a good golf course guy, preferably a fairly recent college grad, he'll be up to date on what is top notch.

Be prepared to keep the area watered properly, that might mean seeding bite size pieces. Consider hiring someone to keep track of it, you can suffer serious setbacks if it goes 85 degrees, bright sun and 25 mph winds while you sit at work for 10 hours.

It would be better to try to treat the soil first. The sprinkler is important too!I agree on the Rachio. We have it too. I find it cool that I get to control a certain zone's sprinkler. It's just odd though that we need to separately buy an enclosure. There are a lot of details online. You should look it up yourself. Hope you'd share updates on your lawn!