Using or eliminating stiltgrass?

I was amazed to find that using the search feature, there are only two posts on permies about Japanese stiltgrass, since according to plant range maps it exists in most of the eastern US, and it's probably one of the hardest to weeds around to eliminate.

It can be respread into an area by animals since it's a reseeding annual, stay dormant up to 7 years before germination, plus deer and other animals dislike it unless presented with no other option since it has little feed value. With those three go the possibilities of elimination by grazing or mowing, using preemergents, or finding any permanent solution to the problem.

So in the spirit of permaculture, I'm okay with just finding an alternate use for it. It's a grass, and although it's considered a broadleaf, it grows so thickly it's not as easy to deal with as other invasives. Give me a perennial variety any day. So far, the only use I've found is as a bedding in spring when it dies off. But the roots also carry some of the topsoil with it, stripping that layer. This plant also has the ability to send flowers up even if cut down short at it's first attempt at blooming.

I've tried cover-cropping on it, but the grass forms such a thick mat that they don't reach the soil in time before they're already crowded out. Seedballs would be useless in this area. And I don't have a seed drill, not that it would work on this terrain.

To make any sort of garden here, I've had to solarize the area for two years before they become sparse enough to be manageable, or put several inches of mulch on top of it. This isn't feasible on a large scale. So anyone else deal with it successfully? Find new ways to use it? This has been a huge ongoing challenge. Thanks.

hi Guerric,

been musing on your question as we also have a huge stiltgrass infestation.

i've been raking back the dead growth and sowing some perennial clover into the bare soil with some camelina since both germinate quickly. not sure how successful this is going to be. stiltgrass has a really shallow root system, so yes i'm pulling some topsoil but not much at all.

in our area, stiltgrass dies back early in fall, so i was thinking that that technique might work best then, as it would give the clover more of a head start. if i remember correctly though, raking back the dead stiltgrass at that time caused more topsoil loss.

what cover crops have you tried and when did you sow them?

p.s. i'm also wondering if mulching with it is contributing to the problem due to seed spreading. might it be better to bury the dead stiltgrass deep in a hugel/pit/raised bed?

Glad I'm not the only one constantly fighting it. Thank you for replying.

I tried white clover, birds foot trefoil, alfalfa, and mixes that involve oats and barley too. And tried winter sowing some of them on snow, and also with the grass raked back in spring. They all grow nicely at first, but they don't grow tall or close enough together to stop the stiltgrass from growing, at least in my experiments. It just germinates in any place the light reaches, and crowds everything out once it gets tall.

If things don't work out this summer I'll try to get the cover crop germinated very thickly in autumn, like you did, then hope it survives the winter and gets a good start in spring. I was hesitant to try this before due to the topsoil loss too. From other examples, I also know stiltgrass will out-grow established crabgrass, fescue(lawn grass), and even pampas grass. Their stalks form a mat on top of the other grasses and prevent them from sprouting properly the next spring. I'm sure it has to have some sort of natural competitor, but don't think I have any on my property.

I don't know how much mulching with it spreads the seed, we already have so much! But most of the seeds have fallen off the plant by spring, so they're pretty good for use by then. I also have chickens and use it for bedding in their coop. Afterwards, it's composted and that heat kills any seeds left over. As long as you don't till it up to the surface again, burying it in hugelculture or raised bed would work. They can't sprout with several inches of soil on top of them.

or you're not the only one, trust me. i had an "organic lawn care" guy come out and visit us who urged me to spray herbicide because my property was contributing to the area seed bank and causing his crews headaches

as far as "exotic invasives" go, i actually don't mind it in certain places, it looks like miniature bamboo and makes a ton of biomass in short order. supposedly, it changes soil chemistry in the forest inhibiting tree regeneration, but there is a recent study out saying that is tree species dependent. the real problem in tree regeneration is the deer.

http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12356/abstract

chicken bedding is great idea, thanks.

this year, i'm going to try to mow it down just before it goes to seed, so at least the seeds produced eventually won't be so vigorous. and keep sowing perennial ground covers. one thing i realized about "invasives" is that it's a long long long battle if you wish to eradicate them. reading sun tzu in this case is helpful.

Most of what i've read have advised getting rid (mowing, pulling)  of it in August to prevent new seed set. I also found a thick layer (3 inches ish) of pine straw has kept the seed bank from germinating in some places where i weeded out the stiltgrass in the late summer the previous year. I've also buried it in my clay for biomass at the bottom of a too deep potato trench. I didn't notice any residue when digging the potatoes this summer, although i certainly had stiltgrass weeds from seed drop when distributing the "straw."

I find the native witch grass/rosette grass (Dichanthelium sp) does not seem as invaded by stilt grass as other grasses. The species i have has rosettes that are green all winter and set seed in the spring. I'm encouraging that grass as my turf.

I've found crownbeard (Verbesina occidentalis) to have seedlings  that out-compete stiltgrass (excellent plant for pollinators, perennial, sprouts each year from a root crown) as do the established plants. Similarly with bearsfoot (Smallanthus uvedalius), another perennial sunflower that attracts polinators and sprouts from roots each year. Bearsfoot is in the same species as the Andean crop Yacón, so that crop might out compete stiltgrass grown thickly.   I'm suspecting that sunchoke (Helianthus tuberosus) will also out compete. Unfortunately, what i need is a competitor for deeper shade.

I tried planting a number of things in the woods to see if they might also compete. I suspect sedges may, and have tried yellow nutsedge or chufa (Cyperus esculentus) which USDA's plants profile has as both native and introduced in my region. I understand wild turkeys in particular make use of the "nuts". I've not gotten back into the woods to see how the plants did. The one i planted in the garden is thriving in a bed where it can fight things out with a mint.  Ground nut (Apios americana) sounded like it might spread thickly enough to threaten the stilt grass, but the test plants at the edge of the woods haven't grown well at all, much less gotten to where they could compete with anything.

It's one of my nemeses, and so i have sympathy for neighbors resenting others keeping the stuff around. Not sure poisoning the stuff is the right track, though.

I am now (Aug 31) pulling flowering/seeding stiltgrass to prevent seeding. The pullings I am packing into black plastic bags and setting in the sun for several days. Is this sufficient to ensure that seeds are nonviable?

Thanks for the thread. I noticed the stilt weed after exhausting or current supply of pine needles for bedding. Chickens seem to like it. Keeps the smell down.