Buttercup wisdom

I'm dealing with a large plot of land in western WA that has lots of big earth mounds on it, which are completely covered in buttercup and reed canary grass, and we would like to clear it of these things to make room for herbs, trees and food in the spring/summer.
I'd like to start doing something to dramatically reduce the population of them ASAP but want to make sure I'm not totally ignoring something..

I'm thinking of doing a combination of a few things, just to see what actually works, since there does not seem to be any one way to do it best that I can gather:
1. mowing/weed-whacking it very short and thickly sowing in some cover crops that might be able to out compete it in the spring, which can then be used as chop and drop
2. letting loose some chickens on the affected areas over the next few months, and hoping they can make way for a cover crop OR
3. trying to manually dig some out by the roots, as much as possible
Unfortunately I think it's getting pretty late for me to be seeding cover crops though, especially if I have to wait until I get the roots all out of there, or wait for the chickens to do their thing, but it sounds like the alternative of smothering with sheet mulch or fabric won't do me much good with these plants (which is probably good for me considering the large area and steep slopes).

The only other thing I want to be sure of is that whatever I put there to try and out compete my troublemakers is addressing the problem that the plants are trying to tell me I have: compaction, wet clay, poor drainage. Also, given that the little hilly areas being affected are so sloped, I'll probably need to be thinking about erosion control...who knows what influence the rhizomatic grass roots have had in ensuring the integrity of the hillsides.. so I guess that is my main question. If I sow in some cover crops or other plants to try to out compete these weeds, are there any in particular that might address the compaction, poor drainage, and erosion issues? Maybe a mix of some vigorous growers and daikon? I have tons of comfrey near the area, which has a good taproot also, but I am not trying to encourage its spreading too much more since we have other plants we want here. Does anyone have recommendations for other erosion control plants/techniques and/or plants that improve drainage & reduce compaction? Anyone had success with eradicating buttercup, or better ideas than those I'm thinking of trying? (Also, I'm assuming that whatever can conquer creeping buttercup can handle reed canary grass too, as tenacious as it is. Correct me if I'm wrong.)

Crimson clover seems to work well west of the Cascades as a winter over cover crop.
It should fix some nitrogen, and can be weed whacked in the spring before it goes to seed.
The chop-and-drop should provide some good nitrogen rich mulch.

Because of your slopes, I would stay away from buckwheat. Buckwheat has a very shallow and light root system, and can therefore encourage erosion. It is OK to use it in a mix, as long as it comprises less than about 25%.

creeping buttercup, ranunculus repens, indicates acidic soil. I think that's a really good thing. I've had a lot more trouble when the soil isn't acidic enough.

Everything looks healthy in your pictures. Just because there's a lot buttercups, doesn't mean it's a bad thing. What kind of beneficial insects are coming to the flowers? It looks like everything grows well with it as it is, so they are not inhibiting the growth of what you already have in place. You may not want to get rid of all of it if it is good for insects. But if you want to back some of it off and plant other things, mow it (it's easier before it flowers), and then mulch it with a minimum of 6" of mowed weed mulch, mulch you've walked on so no light gets through. When it shrinks in a week or two, add more mulch to keep it at 6".

If you want to test for clay soil that doesn't drain well, just shovel out a small hole, fill it with water, and see how long it takes to empty. If it takes more than a few minutes, it's clay. But that isn't a bad thing either. Clay has lots of minerals. It just shouldn't be exposed to the sun. It should be covered with a minimum of 3" of mowed weed mulch, and it will be easy to plant in. It takes a little longer to absorb water, but it holds water in place for plant roots, and you don't have to water as much, especially if you keep it mulched.

That looks like a good location for blueberries.

for erosion control, do you want to plant food, like a food forest, or just landscape plants? You could just do an easy terracing across the hilly part with a rambling S shaped path, as if a snake was working its way up to the top, rather than terracing that is more formal, unless you want a more evenly spaced terraced hillside. An S path would give you 5-6 foot planting beds in between and still keep the water from rushing straight down. Bark chips on the paths would slow any water and still keep it walkable.

There are rock wall terraces that look good with plants spilling over. Even just a foot or 18 inches tall would stabliize the soil and create more structure, maybe with a stone patio up on top?

creeping buttercup indicates not only acid soil, but wet, fertile, acid soil. that's exactly the soil i have and so it's my #1 weed. it's not that hard to deal with. chickens eat it, yes. mulching will kill it within a few months. you can trowel it out by hand - it won't grow back from the white roots but it will grow back if you leave the little flat 'seat' from which the stems grow - you'll see what i mean.

I have so many projects not getting done, I wanted an easy solution. I found it in my carpet garden.

This area is a transition from sandy gravel to clay and was a mix of grass and buttercup. A neighbor had rented his house and a tenant allowed dogs to soil all the carpet so when I passed by and saw the yard full of carpet I asked for it. A carpet laying client says he gets requests from time to time for carpet to use like this and is happy to deliver it rather than pay the dump fee.

I have the carpet rolled up right now. that breaks the cycle of fall seed sprouting in it and it is the time when I cut the standing grass and flax in my field to add as mulch then I will return the carpet from december until planting time

If you can cover your mounds now by spring you wil find critters have been cultivating it all winter. You can cut slits in the carpet and transplant directly through it or roll up the carpet and rake our any rhizomes that remain.

I recall reading John Salveit talk about adding calcium to his soils to slow down buttercups growth. Here's some quotes:

john Saltveit wrote:When I added ag lime/calcium, my buttercups slowed down.

https://permies.com/forums/posts/list/40/44968?OWASP_CSRFTOKEN=VJP0-WDYG-ABGV-BQ3V-NPKB-1ECB-P3DZ-2O1U#360068

and:

john Saltveit wrote:However, and PERHAPS more importantly, buttercups are so incredibly powerful here in the PNW because they are dynamic accumulators of calcium. We tend toward low calcium soils here in the PNW due to heavy rainfall, which perhaps you've heard about. In addition, buttercups and other ranunculae are very unlikely to be in the same family as your vegetables, fruit, or mushrooms, and so biodiversify your yard, adding an entirely different set of microbes to the soil food web and assuring that a balance of soil life will not allow one powerful disease to take over your whole yard. Pulling out the leafy parts before flowering adds that organic material to your yard, which is full of calcium and improves the heavy clay (Willamette Valley) or sand (Puget Sound) so that food grows better.

After I added ag lime to my soil, buttercups weren't wiped out. They just became so much less aggressive which is fine by me. Just make sure you look closely before you eat parsley, burnet salad, or earth chestnut leaves, because you don't want to eat a poisonous buttercup by mistake.

(https://permies.com/t/50653/permaculture/buttercups-blessing)

I haven't tried adding calcium yet, due to lack of funds, but I would really like to! If you don't want to reduce the acidity of your soil, you could add a different type of calcium amendment than ag lime, such as gypsum, bone meal or shellfish fertilizer.

As for things that compete against buttercup, you can try planting a lot of wild or other vigorous strains of strawberries that send out lots of runners. My wild strawberries are almost as vigorous as the buttercup, so I can pull out buttercup and the strawberries easily fill the hole. Aaaaaand, most importantly, I get strawberries!

These are great ideas! Thanks everyone.
Maybe I will try liming some of it as well, and doing some heavy mulching...and I do have some old carpet laying around!

We shooting for a little bit of a food forest in this area, with a Chinese medicinal herb theme (so trees like Ginko, persimmon, hazelnut, with chinese licorice, mugwort, chysanthemum, etc... tons of plants). It's to have a traditional chinese garden type feel with meandering paths, rock features, moon gates and the like, so Cristo I love your idea about terracing the hilly part. Lots of terracing is probably needed in this area. The whole property is a hill with the house at the top and water just rolls away into the stream on one side and the neighbor's property in the back.

I f you contour map your hillside maybe you can get the water to meander between the humps and form ponds for the dry period from July to September. The storms this week have finally got my ponds overflowing. They are sallow and I want to try planting rice in them this spring so I filled them with the flax we have been discussing on the fiber arts thread. I will rake that out when the frog chorus starts. Then I will start experimenting at what temperature sprouted rice will continue to grow. I will go now and post that in my rice thread.

Courtney, carpet is very toxic if it is synthetic or has a synthetic backing. If you can get wool carpet with no backing, that would be okay. But, honestly, if it rains enough cardboard with thick mulch (minimum 6 inches) over the top of it, will suppress just about anything. Or just thick mulch, 10" or so that will shrink to a dense 6" does a great job. Any mowing you do, even of pathways, can be used when piled up and suppresses weeds, brings up the worms, saves on water, etc.

Buttercups are also antimicrobial and antifungal. So while you may want to reduce the population of your buttercup plants, keeping a nice sized patch for you and pollinators might serve you better.

Hi Desiree,

Welcome to Permies!