My grass kill experiment.

At the end of last summer I had 8 yards of yard compost brought into my property to keep the dust down while I waited for the optimal time to seed my backyard. I noticed that the areas where compost had been resting killed the grass. Not damaged the grass, or weakened the grass, but killed it. The only growth has been a little clover and some grass that creeped in from the edges of the kill zone.

So now I'm going to try to kill a bunch of grass this way, in the dead of winter, in the hope this area will be ready for mass planting my March.

I ordered 5 yards of compost at $15/yard + a $30 delivery charge. I covered half of the space today, I hope to have the rest covered by Thursday at the latest.

My hopes: I will kill all the grass, provide my soil with an abundance of nutrients and remove the biggest competition from my trees.

My fears: The compost will cool too quickly, will only kind of kill the grass, and will have me fighting it all growing season. I've made peace with this as a possibility.

Here's a pseudo-before pic. I will update when I try to plant.

I really wish you luck with this. My biggest battle is always with grass. I have much land but removing the grass and perennial native plants slows down my food gardenig.
My neighbours have offered me all the fresh or rotted cow manure I want. Until now I only thoight about the rotted. Maybe I can use fresh manure to kill a large area of grass.
I have built several raisd beds but this takes so much time. I'd rather plant in a large grass free area.

If you have it a good 8" thick it should do the trick. Looks like you have a leaf compost there.. if so know that it will dry fast so I wouldn't recommend planting directly into it but through it into good moist soil.

Well shit, I didn't quite order enough . Got most of it covered. I guess I'll have to dig out the rest, I don't really want to pay another delivery fee. That's okay though I have ideas for dirt elsewhere.

I grew up trying to keep the weeds out of the grass, now the grass is my biggest weed. WTF .

My plan is to leave it on until around the beginning of March, then thin the layer and spread it around to some other places where I plan to plant. I'll then plant directly into the (hopefully) dead grass. I am pretty sure I have 8 inches in most places, but there could be a few low spots, especially near the trees closest to the driveway where I was a little skittish about putting hot compost too close to their roots. I am no longer concerned about the compost being too hot, that ship sailed with a quick rain.

Thanks for your responses.

Here are some more pics.

you could make it thinner and sow a cover crop on top. this will smother the grass and build biomass. this way your compost covers a larger area.

I'm starting to formulate some pretty specific plans for my March plantings, wouldn't a cover crop need to be removed the same as grass would? That and I've noticed everything I've tried to plant in the temps we've been having have met a sudden and alarming demise. I'm pretty new to caring about the plants I'm growing so please correct me if I'm wrong about any of this.

If you plant an annual for cover and cut it down before it goes to seed then there will be no problem removing it. If you plant the whole yard and want to remove it quickly a lawn mower set low will make quick work of it. Or if the soil is loose enough a hoe or stiff rake could take care of it with out much work.

I'm going to stick with what I've got going for now, in part because I want to see this through as is. Changing it up midway renders this worthless as an experiment. I may do a cover crop experiment for a different section of yard, or if this experiment yields unsatisfactory results. Thank you both.

My wife convinced me to just buy more compost so we have complete coverage! Yay!

I have a few places where cover crop may be appropriate. Anyone have any pics of alfalfa or buckwheat in an urban setting? I'm having trouble visualizing because I don't have any scale to the pics I have access too. My fallback is clover and snow peas. Thanks.

Sure you can kill grass with compost, 6 in and you can plant straight into it. If you haven't got enough compost, add a layer of cardboard (above or below, above works slightly better. You don't have to turn the soil at all: check out www.charlesdowding.co.uk he's been running a market garden with this method for 30 years.

Isn't alfalfa a perennial? I don't think that would make sense as a cover crop because you. Would struggle to get rid of it later.

I'm a big fan of deep mulching - it works wonders for improving soil structure, water retention etc... Even before you factor in the nutrient benefits. I spread a layer of newspaper or cardboard down first and have never had a problem with grass coming back through, except creep at the edges.

I've done the more traditional sheet mulching method in the past, and still had minor problems with grass after. The purpose of this test, for me, is to:

1: Determine if it is possible to kill the grass in such a way that the rhizomes die quickly, even in cold weather (I think this one didn't happen, although it still might suffer a longer term kill).

2. Determine if it is possible without cardboard. When sheet mulching in the past, keeping the sheet materials out of the wind has pissed me off to no end. If I can avoid doing that in the future it would be a tremendous help to me. I much prefer moving dirt to laying out paper.

3. Provide an online record with pics that would be easy to find for permies noobs (not unlike me).

I won't be using a cover crop in this patch of grass. I have oats and peas on my list in other areas, but even they probably won't last long in their spot.

So it's been a bit, and I've mostly won the battle. There are places where individual blades of grass trying to come up, mostly near the trees where I piled it a little shallower. I'm doing my best to stay ahead of that. The dandelion leaves apparently will reach straight up in the air if they are buried. I've never seen that before so it was amusing to me. I'll pull the dandelions as I see fit. They are easier to control than the grass. I started planting this week and in the areas where we dug down to grass, the grass looked pretty dead. I know that doesn't mean much yet, but it is encouraging.

Here's a few more pics of this area as stuff starts to grow in.

Overview:



When I find grass, this is what it is looking like. Not an insurmountable problem.



I don't remember seeding any corn here (I believe one of my kids got industrious).



One thing I've been noticing is the top layer seems to dry up and harden very quickly. There is still moisture below the surface, but the compost doesn't readily accept rain after it's dried out a bit. I've gone out and broadforked a little before rains to loosen it up, but it is something to note.

Looks good!

I wonder if adding some more mulch to the top of the compost would help loosen it up and retain a bit more moisture? Even just some grass clippings or something on top might help. I get that problem with bought compost, too, and it's frustrating; I'm trying not to buy it any more, but I'm not very good at making my own either

Thanks!

I will probably leave it as is until I've mostly harvested out, to keep the experiment reasonably pure. After that I'll probably cover crop heading into winter so I have some fresh mulch for next spring. I think that should help.

I need to get stored water up to the high side of this area to help keep it moist, but the logistics of that have me putting it off in favor of other work. Hopefully I can get to that in early summer.

I think it's working.

You've got some great growth there! Are you still getting grass?

Occasionally when I go traipsing through the jungle I'll find a small clump or two, but I'm starting to think most of those are seeding from the top. They're really easy to pull up.

Charles, by any chance were you dealing with bermuda or crab grass?

I have places where some crab grass is coming up, but mostly it's been smothered in the area where I put the compost. It's so fertile there that the grass really doesn't stand a chance.

I have kind of let it go a little (a lot). I've been stupid busy lately with kids soccer and before that just kind of whiny about the heat from endless summer. I tried soooooo hard to not need to water and all things considered did OK, but it's a little ugly right now . Even so, I'm not losing the battle to crab grass, just to a few quinoa and fennel that look thirsty.

That's cool that it's working! Hopefully the start of autumn helps with all frustrations