Killing grass in newly tilled garden

[Doug Kanter]

20 years ago, I worked for two weeks removing grass from a new garden using a fork and a number of custom-made implements of sifting and destruction. I just had a 30x30 area tilled, and this time, I'm ready to try another way of killing the grass that's mixed into the soil. The guy who tilled it did a great job. He ran the tiller in various orientations until the sod was very nicely chopped up. But, you KNOW some of it'll be back in April when I want to plant lettuce.

So: I've seen a number of people mention spreading newspaper. Sheets of plastic are easy, but the newspaper idea is fascinating. But, how's it kept in place? Just toss soil on top of it? We're talking a lot of newspaper here - I'd need lots of bricks. :-) I realize this is an unbelievably simplistic question, but I have limited time this weekend. No time for experiments, and I'd rather not use plastic if I don't have to.

[paghat]

You can cover the layers of newspaper in a thin top-coating of completely composted manure. This has the physical appearance of topsoil, but is sterile so it will not encourage seedlings. Because composted steer manure is nearly black, it also heats up the ground so that even seeds that might otherwise wait several months to germinate will be cooked to death.

If the paper is not completely covered, any that is exposed to the air will dry out swiftly so that worms won't be eating it over time, but when underneath a layer of dampened inexpensive steer manure compost, the worms turn even the layers of newspaper (or cardboard) into nutrients in as little as three months, & nothing that was smothered & heated underneath it will return.

Also, if there are shrubs or tree saplings you would want to plant in the area right away, there's no reason not to cut a hole through the smothering paper & plant a couple big things right away.

-paghat the ratgirl

[David J Bockman]

10-20 layers of paper (or a single layer of corrugated cardboard) is all you need. To keep it down I usually spread compost or mulch, but you could use straw, pine needles, whatever is handy.

Dave

[Doug Kanter]

destruction. I

Does gender matter? In 20 years, I've never seen steer manure offered around here. But, there's plenty of bagged, composted cow manure. And, if it was earlier in the year, I could've gotten plenty of horse manure (from the mounted police stables) and composted it.

I'm assuming it has to be composted because the worms will turn their noses up at it otherwise. Is that correct?

[paghat]

I saw a table once that broke it down into which is best for the rather small nitrogen component. If memory hasn't failed me, in order of percentages it was dairy cow, then feedlot steer, then chicken (even though chicken manure compost three times as much, & less likely to have unwanted salts in it); but they all have the same capacity to induce the soil's microorganisms to produce nitrogen & when used as a topcoating it for the texture & appearance; a top mulch of straw or woochips is to me very ugly, but black crumbling compost looks like a rich forest loam. My recollection is that horse manure had the highest nitrogen count of all, but that's not available as a commercial product round here. I've gotten free llama poo form time to time, but not to use as a topcoating because it's still just pellets of shit when I get it.

In my county, steer manure is a standard product & by far the cheapest compost to buy, so I use it as a surface mulch, but I use a much more expensive organic compost (plus my home-made stuff) when mixing compost into soil. Chicken or dairy cow manure compost would be as good as a surface mulch, but it would cost more. The reason I don't use my own home-made compost for a surface mulch is because it is never as crumbly & easy to spread thinly as commercially prepared steer manure.

-paghat the ratgirl

[dps]

The worms will like horse manure any old way. The problem with not composting it is that, unlike cows, that digest their food fairly completely, horses are just large shredders and the stuff goes through only minimally changed. It therefore contains lots of weed seeds, which the composting process will kill (if it is done properly).

[Bob]

garden using

destruction. I

another way of

tilled it did a

sod was very

when I want

Sheets of

how's it kept

newspaper

unbelievably

time for

One alternative is to re-till it every few weeks untill seed sprouting slows.

It would have been much easier to use a sod cutter and remove the sod and accompanying seeds before tilling.

Bob

[LouiseW]

Re:

According to various places on the web and at least one of my books:

Steer manure has more salt (the animals get salt licks to encourage them to drink to bring their weight up) and more weed seeds. Cow manure, specifically pit-washed dairy manure, is supposed to be better for gardening in general.

Crayfish

[Warren]

Frequent tilling would totally destroy the soil structure, and if done to the same deapth each time would result in powder above the line, and hardpan below the line. Soil shouldn't be tilled more than twice a year. Once would be better.

Maybe. Maybe not. The resprouting is likely to be coming from the remaining roots. A well established turf may have roots going deeper than any sod cutter is going to go. Taking it out that deep may have meant hauling in soil to replace it. Also, after the sod decomposes, the soil will be more fertile than it would be if all of that was scraped-off, and hauled away.

Let me toss in my idea: Go with the multiple layers of newspaper with bovine manure holding it down, and also use it as a dumping place for leaves from the trees. By the time the leaves finish falling in my yard, I'll have built-up a good 4-6 inch layer of shredded leaves over my vegetable garden. A few weeks before planting time, I till it all in. When I started three years ago, the vegetable garden area was as hard as concrete. I almost busted a commercial-grade tiller trying to break it up. I couldn't even get a spade into it. Today, the soil is so loamy that if I walk directly on it, my shoe sinks in to the top of the toe. The tomatoes loved it!

[Gary]

Hi Doug I have read many of the excellent suggestions made by others. I agree to some extent with some of them and others I have not decided. My first assessment (#1) will make you unhappy.

1. Grass is a determined plant. The only way to ensure it won't be in your garden next year is to dig it out. I tried rototilling it and it just came back again and again and again.
2. What you should have done is...are you ready? Remove it totally. How? Well you do it like removing sod. One foot 'squared' at a time. You take out only the top 4 inches or so. And you compost them (Put them into a big pile)...why? Cause the top layers have the most nutritious soil and that's where the worms are. After the grass has died you put it back on the garden.
3. Now what you have is a mess...a mess of grass ready to go next year.
4. I'm not sure how plastic or paper will help. I am assuming you are in the USA and unless you are in the southern states lettuce will not grow. So...
5. Pre plant your seed indoors and then transplant them when they are bigger. While they are growing (indoors) disturb any greenery you see in the garden area...that will be the grass growing again.
6. After transplanting your seedlings continue to disturb the roots of any greenery growing. Eventually they will be gone...eventually! I know. It does work.
7. Now you know as much as I do about removing sod for a garden. :) Regards, NN

[Ann]

"Bob" expounded:

There will be weed seeds anyways, you'll never get them to all sprout. As Warren said, aggressive tilling will ruin the soil structure.

By tilling in the sod you gain the benefit of the organic matter. I think the newspaper idea is the best way to get rid of the rest of the grass, especially when you have the time.

[Doug Kanter]

Yeah....I heard about the sod cutter idea, but hiring someone for that was very expensive, and nobody rents them nearby.

[Janet Baraclough..]

The message from "Doug Kanter" contains these words:

I use flattened cardboard cartons to make new beds on old lawn, or overgrown areas. Overlap them like tiles so no light gets through the gaps. To hold the card down and hide it, I cover it at least 6" deep with grass cuttings and/or seaweed.(I have endless free supplies of both, from lawn contractors and the beach). Any organic material will do. Worms take the whole lot down into the soil faster than you'd believe, leaving a rich weedless bed. You don't have to wait that long for planting;just cut an X in the card and open a space, plant through the hole and tuck the mulch back down.

Janet.

[Janet Baraclough..]

The message from "Doug Kanter" contains these words:

Often, but not where manure is concerned.

In 20 years, I've never seen steer manure offered around

Go for it.

No, they'll love it at any age, but very fresh manure heats up in the first stage of decomposition, which can damage soft stems and roots near the surface. Some fresh farm manures contain grass seeds, so I either put it in the compost heap (great activator) or if I'm using it to make a new bed, under the cardboard/lawnmowings/ seaweed, to stop the seeds germinating.

Janet.

[Janet Baraclough..]

The message from [e-mail] (LouiseW) contains these words:

The licks given to cattle are mineral salts such as magnesium, an essential part of herbivore diet, nothing to do with making them drink more. Mineral salts and liquid intake are processed by the kidneys to the bladder and eliminated in urine. Even by dairy cows.

Bovines, male or female, digest food through several stomachs; so their manure is far less likely to contain viable seeds than manure from horses, which have only one stomach.

Janet.

[paghat]

Louise erred only in her statement as to the source of the greater number of sundry mineral salts in feedlot-steer manure. The salts come from the bottom-of-the-barrel garbagy fattening feeds given to steers to maximize their weight before slaughter (for the same reason that farm-raised fish have more mercury than wild -- its from the unfit-for-consumption feeds made from all sorts of garbage). Dairy cows aren't forcefed the same kinds of low-grade feeds so don't get the sundry pollutants in their turds. The usual gardening assessment, however, is that the higher percentage of salts in composted steer manure is still such a small percentage that it wouldn't hurt even salt-sensitive plants, plus it washes through the soil after a couple of hard rains.

-paghat the ratgirl

[simy1]

I find cardboard to be more practical. The box of a large appliance will cover some 50 sq ft, so you will need less bricks. The loft of my garage is always full of cardboard, for that purpose. On the other hand, I would never cover the plot entirely with cardboard, I would use the chance to establish pathways with bricks or cinder blocks at the edges, with plastic covered with gravel in the path itself. You also want to establish a mowing strip around the garden, same method (plastic and gravel). grass is one tough garden weed and it will come back in via rhizomes if there is less than a foot and a half from lawn to garden.

Also, you don't put the cardobard down now, when nothing grows, because that will fail. Once the paths are in place, you mound manure on the beds and retire for the winter. You wait until just before you plant your garden, in April or May, so that you will be weed free for most of the season and will effectively kill all seeds that did germinate. Say you plant one bed in April with lettuce and chard (this are Michigan times), you cover it with cardboard, punch holes through, and plant the plants. In May and June you will do the same with the other beds. Sorry, but the first year garden will not accept direct seeding.