Marco Banks wrote:
If weeds and blackberries are a problem, you could you cover them with black plastic to discourage growth, and then cut through the plastic to plant vining plants like watermelon or cucumbers. Do you have access to an excavator? If so, it would be easy to sculpt the pile the way you want it. You could create mini-terraces on it, and then put down plastic on the steep sides and channel the water via small swales to water exactly what you want to get water. Can you imagine if you planted it with pumpkins? The pumpkin pile!
I'd kill for a 15 foot tall pile of decomposing stuff. I'm terribly jealous. Go crazy with it!
I once thought covering a bunch of sticks and salmonberry and blackberry with black tarp would kill the bindweed that was growing there, too. Well, it kind of worked, but what really happened was that water and snow pushed the black plastic down onto the branches...which then poked holes in the plastic, which then turned into rips, which then degraded in the sun. And now, I have tiny bits of black plastic everywhere and that's really hard to remove because it would require pulling out all the branches to get to the base of them where the plastic settled, as well as either reaching through blackberry and salmonberry to get pieces, or hacking out and removing all those canes to get to the plastic. It's a nightmare. And, it's been two years of being pregnant &/or carrying a baby and I haven't been able to remove the plastic, and it keeps becoming smaller pieces and the plants grow up and through it more.
Moral of my Story: I will never use black plastic again!
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But, I do recommend the slash pile. We made one, intending to haul the sticks to the woods but never got around to it. And, the mason bees and garter snakes have taken up residence there. And, since it's right by my fruit trees, I unintentionally made a pollinator habitat--score!
Some of my other slash piles were where blackberry grow, and they have become blackberry covered...which is actually a nice way to get some blackberries! And, after a few years of settling/decomposing, it's really not that hard to remove the sticks and blackberries if you want to (especially if you do so in the fall). If there is a lot of blackberries (especially those nasty Himalayan or evergreen blackberries), and you've got lots of dirt, a giant hugel would be great. But, the blackberry/salmonberries will grow up through feet of dirt, so if they're there, you're going to fight them one way or another.
Personally, I like to fight blackberry by encouraging competition from other yummy, less painful and slightly less vigorous can fruits. Here's the progression I take when remediating a site (on the left is things I remove first and let things to their right out compete. Once they're gone, I start working on removing the next nasty one):
Bindweed -> Evergreen blackberry -> Himalayan blackberry -> salmonberry -> trailing blackberry/thimbleberry/blackcap raspberry/domestic raspberries (these last plants are all valued by me, so I encourage them all)
So, I first keep hacking back at bindweed and pruning to encourage all other plants that are attempting to grow there. If there's no bindweed in an area, I attack Evergreen Blackberry and Himalayan blackberry (Evergreen blackberry is even pokier and seedier than Himalayan--it's thorns are long, sharp, and slightly hooked, so they're really panful and hard to evade!), while encouraging the salmonberry. Once there's mostly salmonberry growing somewhere, I start introducing & encouraging the raspberries/thimbleberries & blackberries. This is the stage I'm at in most of my property. I can't tell yet if it'll be perfectly successful, but so far, this process does seem to be working and I have less of the plants I don't like!