Hi Rick,
I am wondering the best way to get rid of grass coming back into my food forest.
When I originally planted most of my food forest 3-4 years ago I laid cardboard topped with 6-12" of wood chips as mulch. Last year I noticed some grass creeping into the area and this spring it is coming in even more.
I want to get rid of the grass once and for all. The plantings are pretty close together, it would be very difficult to get any sort of sod cutter/scraper in there.
Is there any groundcover/understory plant that might outcompete the fescue grass? I am located in the northeast so it seems like the grass is exploding with growth right now.
Thanks for the advice!

Why would you want to get rid of the grass?

It will send down roots and increase the organic matter in the soil. it will shade the soil from the sun.
You could run chickens on it and they will probably eat it down a bit.

You could wait ten years until the trees are tall enough to shade the grass out--then it will get sad and die.

having said that, if I have an area with grass and I really want to kill it, I cover the grass for at least 6 months and then when I uncover it I plant desired seeds very densely.

I try to only fight battles that I need to win. I pull and fight things that produce stickers and thorns that can hurt me. Otherwise, if it is green, it probably has a purpose.

I'd say if you don't want grass best to plant something else there. Mulching it won't be sustainable. You didn't plant any guilds?

Plant something else there wouldn't that imply getting rid of grass? Simply planting something doesn't get rid of grass especially in a well established yard. My personal experience involved the very laborious task of turning the top layer over or wheelbarrow somewhere else and then layer on leaves and woodchips. Grass still comes up in spots but I'm hoping it wont be able to compete in the long run after things get established.

I think in most places we will find that grass is what is supposed to grow most anywhere that something taller or thicker isn't growing.
It has a purpose.

To try to fight it is just going to cause a lot of wasted energy.
You don't need to cut it or care for it...just let it be.

If I need to plant something that REALLY needs to have no competition--then I just throw a piece of wood or plastic or a pile of wood chips etc...on the ground 6 months ahead of time. when I pick it back up, everything has turned to mulch/worm food and the ground is ready to go. At that point whatever I plant will outpace the grass.

Marc he is trying to establish something resembling a forest. I rarely see grass as the predominant player in any forest. I think his original question implied looking for a practical, less intensive way to get rid of it. In practical terms how long do you think doing nothing would get rid of grass?

It depends what you plant.

When I plant vines, they discourage grasses very quickly because they grow on top.
My sumac is in year two and it is already 3 feet high and will probably start shading out a significant amount of grass by next year.
An apple tree will take many more years to get large enough to discourage grass growth.

But i think the real question remains. Why do we want to get rid of grass.
It is a pioneer plant. As permaculturists, we are supposed to like pioneer plants.
In ten years if you plant your forest densely enough, you may have a full canopy and your pioneer plants will die off.
But until then, the ground needs to be covered with something--preferably something that grows.
Grass serves that need very nicely.

You could kill it off, dump 8 inches of wood chips on top and let it sit.
Very quickly wild grass seeds will blow in and new grass will grow as soon as it can.
They will then send down roots, act as dynamic accumulators, increase biomass and protect the soil from solorization.
Enjoy the grass stage.

Trying to say you don't want grass in your food forest is like saying you can't stand your two year old because he cannot hold an intelligent conversation.
When he is 30 years old, he might hold an intelligent conversation, but when he is two he will run around and bump into things.
Enjoy that stage for what it is. It is preparing him for tomorrow.

Mark, I think the reason he wants the grass gone is because it inhabits the same rootzone as the apple tree, thus depriving it of nutrients, and therefore a less-hardy tree. There are quite a few other plants that can grow under trees that don't take up that same rootzone, such as shallow growers like strawberries and deep growers like dandelions. I've been told that I should go so far as to remove all plants for three feet around the tree to reduce competition, especially around young trees (http://www.permies.com/t/36743/forest-garden/Sheep-Sorrel-Apple-Tree-Seedling, http://www.permies.com/t/46814/trees/Prune-Fix-Trees).

To answer Dave's question, this thread has a lot of suggestions: http://www.permies.com/t/39835/trees/rid-grass-Apple-tree-guilde, such as planting comfery, rhubarb, horseradish, sweet potatoes, or lemon balm, . Or, applying a deeeep mulch, or inoculating with fungi (a nice way to do this would be to use nice leafy forest litter as the mulch.), or running sheep/chickens/geese around the trees. Another person mentioned that if you keep the grass cut short, it won't develop as much of a root structure, and so will not use up as many nutrients.

What I do--and I only have two years of experience at this!--is lay down old paper sacks, cover with forest litter or woodchips (grass clippings don't seem to work as well), and plant bush beans and peas, as well as comfery, dandelions, nasturtiums, and strawberries under the trees. I still have to pull grass by hand under most of the trees, but there's quite a bit less of it to pull, and it will hopefully soon be out competed by the other stuff.

I hope that helps answer your question!

The fact the grass is establishing is tell you that there is a niche unfilled there. You can't get rid of grass without expecting something to fill that space.

You might want to get rid of grass because it's roots are antagonistic towards those of fruit trees like apples. They share a root zone. Other plants that fill the same niche might not have competing root zones and might bring in other useful functions. I like strawberries because they run and fill gaps nicely. Also comfrey for it's chop and drop potential, rhubarb (edible, big broad leave that shade out most things once established), berry bushes like redcurrants, globe artichokes (deep tap rooted, leaves spread and shade the soil), spreading herbs like creeping thymes and mints.

So, I would flip your question round to be... what can I put in this place to fill the niche...

Contrary to most I do not mind a little grass in my forest garden. In some areas I have clumping grass that I constantly cut for organic matter and they do not seem to bother anything. On one berm I have a row of clumping grass that attracts boat loads of critters.
Those are both in dense planted areas.
In a different area I planted into Bermuda grass. It coexisted with herbs, trees, and a lot of chicken plants. The lambsquater, dock, mulberries, etc keep the grass lame, there is no reason to struggle with it at this time. By the end of last season I did not see any bermuda, because the taller plants had it blocked out and dwindling. Fight plants with other plants

Some plants that trump grass (and sometimes bindweed): perennial arugula, densely seeded clover, comfrey, creeping thyme in a well-prepared site, oregano, lemon balm (melissa). Culinary sage would probably work.

Does not trump grass: chives, borage, daffodils, lavender (although it gets close).

My experience in a pretty dry climate. YMMV if it's wetter.

ETA: All that said, I have a fairly ecumenical approach to grass in my food forest, because my observation is that it may actually help retain water better than clearing it away from the trunks. Another way to stop fighting tall grass is to seed in some low growing grass and just let it go. In my area you can buy "cabin mix" seed that grows only 12" high. Let the short grass trump the long grass and forget about it. Or get some buffalo grass. Life's too short to fight sometimes.

Thanks guys for all the tips. To give more info on my situation, I have strawberry, comfrey, rhubarb, Raspberry, elderberry, groundnut, garlic, various mint, lingonberry, currant, daffadil, beach plum, low bush blueberry, various annuals, and a bunch more things I can't remember right now growing in the understory.
Some of these plants are being overtaken by the grass which is why I asked the question in the first place. I'm not particularly against the grass I am just trying disadvantage it enough to keep it from swallowing up some of the plants I want to gain production from.

dave, encouraging the ground ivy spread also might help.
just have to watch out for any japanese siltgrass taking over in your bare spots (it's starting to sprout now).

Dave,
I've used clover and comfrey to good effect to compete away grasses in some areas. But getting rid of grass "once and for all" would be a more intensive operation and I'm glad that so many people have offered what worked for them. You will probably have to test which ones work best for you.

This might be completely unhelpful, but some plants parasitise grass. The two examples I know are yellow rattle (or hay rattle) Rhinanthus minor and eyebright Euphrasia spp. Would using a plant like this to suppress the grass give the plants you want to grow more of a chance? Or is this cheating, and the only solution is to say "why is the grass succeeding at the expense of the comfrey, how do I improve conditions so they favour comfrey" and if the only answer is "comfrey requires more shade" you will just have to wait for the trees to grow?