Last year I bought a stella sweet cherry tree from Gurneys.com and planted in my garden. I saw it leaf out in the spring and then slowly die from the top down. What I learned later was that it was really dying from the bottom up. That is, the roots rotted in the waterlogged soil. This kind of tree does not like wet soil. Enter hugelkultur. Credit goes to Paul Wheaton with his article about it on permies.com, where I was introduced to the concept, and with the ongoing discussions, experiments and successes going on at the forums, I gathered enough information to recognize it as a potential miracle. Self fertilizing, self irrigating- and it also happens to be a kind of raised bed. Thus add self aerating to the mix. Just what I needed. Hugelkultur is basically a mound of soil on top of rotting wood. The wood acts as a sponge, holding water for much longer than in a regular garden bed, and it also acts as a substrate for beneficial fungi. There is a symbiotic relationship between plant roots and fungus mycelia- a sort of nutrient exchange that goes on between them. Some relationships are species specific, but I am taking a gamble that a more general exchange also happens, or that the bed creates the ideal conditions to facilitate the evolution of symbiotic fungal-bacterial-plant root polycultures. We'll see.
Gurney's nursery promises to replace any tree as long as your garden exists. So I e-mailed them and they were as good as their word. A new one was sent this past week. It arrived Saturday, on a rainy day. It came as a bare root and needed planting that day. So I had to construct the bed in mucky soil. Not the best day for excavation. First, I used an A-frame level to make sure I placed the bed along a contour. This is so it would receive runoff evenly. I removed the sod, then a little soil beneath it. Next, I added a layer of old, rotting firewood, then returned the sod upside down, followed by the last of the excavated soil. I dug another layer of the clay subsoil on the uphill side of the bed to create a small swale, packing the clay into the side of the bed at the bottom edge. I added a layer of half finished compost to the top before planting the cherry tree and seeding the rest of the bed with oats, clover, snap peas and carrots. I will probably add a few strawberry plants as well.
Two days later it rained again and the swale filled with water. Extra water drained via the buried tile that runs under it into the pool on the far right. However, it is also full. Anyhow, the swale kept the water longer, and I am hoping it will function to recharge the buried wood in the bed during dryer times, capturing afternoon thunderstorm runoff, and reducing evaporation speed through it's simply being concentrated for a little longer in that space.
For more hugelkultur step by step photos, go here.