Swale-berm plant/pigweed management - Ctrl Texas

Mid June 2024 professionally installed swales and berms in Burnet, TX - approx 1100 linear feet, on previously overgrazed dead pasture. Berm soil was calcium-rich (from limestone) in quickly-draining clay/rock/dirt. The rest of that pasture is crusted over. The berm portion measured along the curve is 15 feet deep.

Summer soil builder cover crop from greencover.com sown under dairy cow compost on 2/3 of the berms - I'll call those A berms. We ran out of compost. B berms (those without compost) were seeded but nothing grew.

Cover crop on A berms took off for about 1.5 months as did corn from the seed bank, then we had 7 months of only 3" total of rain - atypical. I let the plants just keel over in the lack of rain and I don't think anything reseeded.

Late spring 2025 when rains started coming back, I put out the same cover crop on B berms - with compost on top. Sprinkled a small amount on the other berms which had lots of dead plants shielding the soil.

Cover crops on B berms started taking off. On A berms, new plants that I had not planted started coming up. When they got bigger, turns out they were mostly Palmer amaranth/pigweed and some other types of pigweed, and they quickly took over almost everything except a welcome smattering of sunflowers which were part of the cover crop mix but came up for the first time this year, and local weeds and wildflowers which I don't mind.

On one set of A berms, the pigweed is on its way out, so super seeding time. Not great.

One small set of B berms still had flowering and maturing pigweed, and I decided to pull the small to medium-sized plants with roots attached and cut the large ones at the base on 100 linear feet. The roots looked great, and the soil looked much browner than it had been. So I thanked the pigweed for its service.

I just ordered a farmers friend silage tarp which will cover 200-feet worth of berm at a time. I was planning on laying it out black side up to have the pigweed germinate, then get smothered, without killing the soil. Of course, I can't really do the weed torch method by only leaving them covered for 1-2 weeks, like a YouTube comment said Curtis Stone did, because I dropped pigweed in place to feed the soil. I don't have enough summer left to get 6 weeks for each 200 feet, though I have no problem leaving a tarp on during winter for the last run. Also, I don't mind focusing on a section each season and nipping those seedlings in the bud in the spring manually.

Since we are not at this property more than once or twice a week for a few days total, we can't really figure out a way to get pigs on, which would be a nice, multi-purpose solution.

Anybody have any ideas on managing these berms? I want them primarily for trees (fruit, timber, shade) and shrubs in the coming years. I am patient and will wait till succession happens and all of that.

Thank you!

Have you check out Sorghum-Sudangrass?  It is drought tolerant and will improve the soil.  Buckwheat is a 2nd choice.

Since you ran out of mulch, grass clippings or leaves would work.  Grass clipping are usually abundant this time of year.

Sounds like your plan of action would work though the berm will need to be reseeded and watered to keep the pigweed from coming back.

By the way, did you know that pigweed is edible and nutritious?

https://www.bbg.org/article/weed_of_the_month_pigweed

https://permies.com/t/68756/Red-Pigweed-Palmer-Amaranth-massively

Thanks for your comments and links - I had missed that permies thread in my searches. Doesn't look like most permies stress about pigweed too much and believe, as I do, that they are there for a reason and to help the soil. I'll try the young leaves soon - I do have a few seedlings popping up again after our heavy recent rains. The gift that keeps on giving indeed!

I got an offer by someone in my GSD - Get stuff done - group to rent her pigs to me and I know she's very health conscious and doesn't do yuck stuff. Of course, before I entertain her pigs I need to figure out how to take care of them, transport, and set up systems for them - haha. At least this is a really nice option that I may or may not exercise.

I have large bags of buckwheat seeds plus the warm season cover crop mix contains Sorghum. I will definitely be seeding in the fall another soil building cover crop blend. And in the spring seeding again. Anybody know if I have to do compost again? That was a huge expense.

A local tree service can provide me with more wood chips. If we have a typical dry summer (after our tremendous amounts of July 4-8 rains - we got about 16"), I could wait till the amaranth on the remaining berms just die down. Do the silage tarp on an area or two as an experiment.

We also have access to free spent mushroom blocks which will be great once the weather is cooler.

I am thankful that the overgrazed pasture between berms is still pretty static, so I don't have to plant there for now. Though I'm interested in the basalt dust that is recommended by the Symbiosis TX permaculture aficionados.

Anyway, thank you for the info, Anne! I am feeling better already!

Wood chips, mushrooms and pigs sound great!