Thursday, May 16, 2013

Huhu Grubs and the Hugelkulture Influence

Wood on newspaper

I've been given a lot of rotten wood to use in my garden, as a layer in the raised beds I'm developing in the front yard. First I put down a layer of carpet or cardboard or newspaper to suppress the weeds, then I pile up rotten wood, then  dollop on home made compost followed by a layer of soil on top to plant seeds and seedling directly into, then finally mulch. I'm inspired by a permaculture technique called Hugelkulture which combines carbon sequestration with soil enrichment. It's a big project and I'm progressing slowly but steadily.

A huhu grub pokes it head out of its hole, perhaps surprised to breath fresh air?

The advantage of building up a raised bed with rotten wood is two-fold.  The wood will act as a sponge, soaking up rain during the wet winters and releasing it slowing into the soil as it dries out over summer. I shouldn't need to water these beds much, if at all, the next time there's a drought like the one we've just come out of.  Rotten wood doesn't just release moisture though, its chock full of microorganisms busy converting wood into compost which makes for a rich  fertile growing medium. I expect these beds to grow abundant, healthy, productive plants.

Another huhu grub reaches across the newly divided log, looking for its fellow grubs?

Some of the organisms doing this important work are not so micro.  Inside one log, a family of huhu grubs, each the size of my little finger, had turned the wood to mush. They seemed quite startled to have there mushy home split in half by my axe.  After photo time, I pushed the halves of the log back together to let them get back to their carbon sequestering activities.

A third huhu grub landed on the ground letting me have a good look at its pallid, plump, caterpillar-like body. 

On meeting my huhu grubs, I did consider the United Nations' recent recommendation to eat more insects as a valuable and sustainable source of protein.  But... I feel I'm pretty well supplied with more palatable sources of protein just at the moment. Frankly, the wood-composting contribution of the grubs to my future diet of home grown fruit and vegetables seems more valuable than a mouthful of "buttery chicken" flavoured larvae (according to wikipedia).

Huhu in motion

My first hugelkulture bed, half finished.  

I just  reread the hugelkulture article, and remembered there's a lot more advantages to rotten wood in your raised beds than I mentioned above.  They  are 

"loaded with organic material, nutrients, air pockets for the roots of what you plant, etc. As the years pass, the deep soil of your raised garden bed becomes incredibly rich and loaded with soil life. As the wood shrinks, it makes more tiny air pockets - so your hugelkultur becomes sort of self tilling. The first few years, the composting process will slightly warm your soil giving you a slightly longer growing season. The woody matter helps to keep nutrient excess from passing into the ground water - and then refeeding that to your garden plants later."


Unknown said...

Thank you for this post! I'll give Hugelkulture a try ...

Carol said...

Very interesting! I think I'll give it a try too. I'm enjoying these gardening posts, thanks Meliors.

Carol said...

Very interesting! I think I'll give it a try too. I'm enjoying these gardening posts, thanks Meliors.