Question
I do not live in the USA I am in Canada on the West Coast of British Columbia. I have had nothing but trouble with my back yard with weeds. So I finally gave up on it and decided to start over.  I rented a sod cutter and lifted all the weeds and some sod off the entire yard and am going to till the soil and level it with some good top soil. I know the seeds from the weeds will still be in the soil but is there some other else I can do prior to applying turf? Some other treatment to the soil.  I haven't checked the pH of the soil yet.  

Thanks in advance!!

John

Answer
I've said it before and I'll say it again: You CANNOT grow a great Lawn without great Seed.  And you can't grow great Grass without great Soil.  It all begins with your Soil.

What I'm saying is, You think you have a Weed problem.  But what you had was a Soil problem.  Great Grass does not give Weeds room to roam.  Great Grass gets mowed at a height calculated to boost the Grass and bust the Weeds.  Great Grass grows ONLY in great Soil.

So, if you have not ordered your Good Topsoil yet, my friend, CANCEL THE ORDER.

And make Lemonade out of last year's Lemons.

Topdress your Soil with Organic Matter, Humus, Compost, Aged Manure.  Even a little Peat Moss.  No 'Good Topsoil' in the world is going to be as good as the rich, home-made Earth you create yourself.

Think about this: 'Manure' as an amendment is one of the richest sources of organic matter you can put on the table -- slow-release N-P-K, micronutrients, soil structure enhancements and other components of great Soil.  I would be very, very surprised if anyone sold you a 'Topsoil' that included supplemental Manure of any sort.

Just like that old gardener's saying goes, If you want to do something right, you've got to do it yourself.

Now what?

Surely you don't want to put Grass seed down in ... July?

Grass planted now is doomed.  The roots have no chance to develop in blazing Summer heat.  Half the Grass hormones will be yelling 'Hit the Floor!' trying to go dormant to endure temperatures Grass was not born to bear.  The other half of the Grass hormones will be screaming, 'Going Up!'  It won't be mature enough to go dormant.  It won't be strong enough to stay un-dormant.  It will fizzle, it will weaken, and at the end of the day it will kick the bucket.

Much better to sprinkle Clover Seeds across that blank Soil canvas.  Clover is a cover crop.  You keep out Weeds that way.  Plus each Clover plant pours Nitrogen into your Soil, making it exceedingly healthy for Nitrogen-hungry Grass Roots when your Grass next year is done with its Summer nap and enters its final growth spurt before the long Winter sleep.  Clover is worth its weight in gold.

(By the way, I hope you saved that sod layer and composted it for future use.  Nothing like a pile of homemade Nitrogen to feed your Lawn.  Unless you had patches of Quackgrass.  If so, please advise.)

For now, start with a little light Rototilling.  Not too much.  Just enough to break up your Soil.  I repeat: NOT TOO MUCH.  You do not want Soil particles so tiny you can create your own Talcum Powder.

You see, sir, we have heavy Clay Soil here on Long Island (what DO you have over there on the left side of North America?).  Over-working it creates fine, microscopic particles of Silt so fine it qualifies as dust.

You don't want that.

You want to keep as much of your Soil intact as possible, protect the tilth you have.  Tilth is a beautiful thing.  It dictates Soil Structure, it attracts Earthworms, it is the basic property of great Soil.

Shovel in a VERY generous amount of organic matter.  Manure, Compost, Humus, Leafmould, whatever.  Remove debris and rocks.  Rake smooth.

Since we're a few months away from Autumn, you still have time before it's Grass-Growing Season.  Which means you have that time to build up your Soil.  Time to get rid of Weeds.  Time to have your Soil tested (how far are you from Washington State?).  Plus you have time to pick out and order your favorite Grass Seed.

Since we're on the topic of great Soil, it really is important to make your Earthworms happy.  They quickly transform the banal into the beautiful.  Earthworms are widely viewed as indicators of good Soil quality.  But they need a THRIVING population of microbes, not to mention truckloads of organic matter.

The Summer grace period you have before seeding offers another opportunity: Cover crops.

As you know, Nature abhors a vacuum.  Cover crops are what you grow to take up space so Weeds have nowhere to move in.  They also enrich Soil while they're at it.

Why not read 'Improving Soil Structure' at the Arizona Cooperative Extension website to expand your options:

www.ag.arizona.edu/pubs/garden/mg/soils/improving.html

'Any fast growing annual plant that is easily killed will make a good Green Manure crop... Cover cropping provides additional organic matter, holds nutrients that might have been lost over the Winter, and helps reduce erosion and loss of topsoil.  Legume cover crops can increase the amount of Nitrogen in the Soil and reduce fertilizer needs.'

And if you are dealing with compacted soil, they point out, 'A deep-rooted cover crop allowed to grow for a season in problem Soil can help break up a hardpan and greatly improve tilth.'

A cover crop like Alfalfa enriches your Soil and breaks down Clay, if you have that.  Alfalfa roots are so effective for this it's scary.  They pour Nitrogen into the soil, and they penetrate the Clay with a strength and intensity you could never do manually without wrecking Soil structure.

I can understand that you would be concerned you will get more Weeds when this exercise is over.  Since getting rid of the Weeds is the point, you want to make sure you get rid of every last one.  Right?

Well, let's talk about that.

First, a thick Lawn (the kind you grow with great Soil and great Seed) is very good at repelling most Weeds.  With nowhere to go, they can't make contact with the Soil, which means the Weeds can't grow.  Period.

But of course some Weeds are very good at this anyway.  Some Weeds go through blacktop and concrete.  Some Weeds can be vaporized with those little walkaround flamethrowers people use to barbecue renegade Weeds around the yard.  Some Weeds (the really ugly, scariest ones) ENJOY being barbecued; it actually stimulates growth.  So we have to know what Weeds we are talking about here.  If you have i.d.'d any, let me know.  I'd venture a guess that Annual Bluegrass is one of them.

However, there are some interesting things that scientists have learned about Weeds.  And one of those things is that Weeds can be weakened and eventually destroyed JUST BY MOWING THE GRASS AT A CERTAIN HEIGHT:

www.helium.com/items/981092-the-correct-height-to-cut-your-lawn

University of Illinois did a test to find this out.  Their plot was planted with Tall Fescue, which is a cool season Grass.  They discovered that Weeds did best when Grass was mowed at 1 or 2 inches.  'Crabgrass populations increased as mowing height decreased...'

www.turf.uiuc.edu/research/summaries/1994/94_3.1.pdf#search='university%20test%20mowing%20height'

Got that?

Weeds are low on the ground.  They need light like everybody else.  But with thick, tall Grass all over the place, they get less of it.  And the thick, tall Grass gets more.

The Better Lawn and Grass Institute points out: 'Proper mowing, watering, and fertilizing practices develop a lawn that needs less chemicals to control Weed, insect, and disease problems.'  Here's their URL:

www.turfgrasssod.org/lawninstitute/guide.html

Almost seems to easy to believe.  But it's true.  Mow right and you mow those Weeds into the ground.  Mowing WAKES UP your Grass.  Lawns that are strong.  Stronger even than Weeds.

Now, get a sample of your Soil and have it tested.  I'll do my best to find out where that would be, but you have GOT to get up close and personal with this Soil so that you can tackle these Weeds and build up that Grass.  Know thy enemy.

A Soil test will give you all a list of the things that your Soil HAS... plus all the things it is MISSING.  Look at it this way:  You'll save money with a Soil test, because you won't be buying things your Soil does not need.  No one needs to throw money out that window.

Scientists take their lab equipment and analyze your Soil.  Then they tell you whether or not you need MORE of that Manure, and precisely how much more, if any.  Soil tests are not expensive -- one test will cost you less than a tank of gas.

Ready?  Busy week for you.  Thanks for writing.  Keep in touch.

THE LONG ISLAND GARDENER