Hugel
ever looked into hugelculture
Actually, yes and I have been doing it (before I knew what it was) since 2005 in a lot of the erosion ditches on my property. Learning about it has encouraged me to refine my processes and selectivity a little.
Pine/conifer species don't work well for hügelkultur as a general rule. Hügelkultur needs coarse grain wood species with low tannins and non-aromatic/non-volatile resins that will easily absorb water and rot. Pine/Cedar will tend to repel the very things (bacteria/insects) you want in that pile to break down the solids. It's OK to put a well-rotted pine log in a hügelkultur, as long as there's no 'seasoned' wood in the center that's waterproofed with solidified resins. Save that stuff to make pine kindling for starting campfires. Chip your cedar and seasoned pine into stuff you want to use for flower bed covering. It'll keep some of the unwanted critters off your flowers, but may also detract from favorable dirt dwellers, too. But it won't rot as fast as hardwood mulch. DO NOT use any untreated chips for mulch near your house. Not unless you want to turn your home into a buffet for termites. Anything 50 feet or more away gets the stuff from my clearing activities. Those beds tend to have the better flowers.
It's best to avoid denser grained woods like cherry and black walnut, too. Denser grained woods are typically not well suited to hügelkultur because they don't absorb water fast enough. They chip pretty darn good, though, which helps break up the grain and fiber, and promotes water absorption. Dried cherry can be a little hazardous because it shatters and flies apart. Use that kinda stuff mixed with other softer species for the filler between the logs before you cover with mulched leaves, then soil. If you're doing this on a sloped and eroded lot like mine, the soil will cover it nicely as the leading edges decay, and it will hold water in very well. Some of mine seep water for weeks after a good rain. This also tends to make them self-leveling and encourages grass growth in the sandy run-off soil.
Anything that's chipped up will decay faster than large solid pieces. Large solid pieces have the advantage of filling the holes quicker and decaying slower, but they will leave voids that will encourage burrowing rodents and pests, even larger critters like fox. Dunno if yellow jackets have a presence in Germany, but a hügelkultur is a haven for them because it's easy for them to burrow in the very same soil that promotes good growth. Keep that in mind. I do not encourage yellow jackets to do anything but die. I usually take out at least 3 nests every year.
Damaged knives are almost a foregone conclusion with a
chipper. A very small quartzite rock (river rock) can do a ton of damage. For that reason, I try not to put anything that's been in the soil in my
chipper. I never chip stumps or roots, and NEVER put raked up matter in my
chipper. I have a flail shredder/
chipper for that stuff if I don't decide to just rake it in on top of any logs that I haven't covered yet.. The shredder has a small chopper blade in the center that looks like an edger blade, but it's only for hacking bits off larger chunks. If it's too big for that, it gets laid in with the log bits.
Just start with the big stuff, and work your way down to grass clippings (if you don't treat your yard with pesticides). Clippings/leaves from a treated yard will likely be counterproductive in a hügelkultur.