One of the sources of green fill for my paddock holes is arborists working the area. When they have a big job they can get caught with too much woodchip. We're exactly halfway between Myrtleford and Bright, and neither waste/ "recycling" site will take more than two cubic metres of waste a day. Which sometimes includes woodchip. The arborists get stuck with it. If the job is in or near either town there is usually someone who will take a load for their garden, and realistically its not worth the arborist driving their truck out to my place. But when the job is near to me, and they are already full and have more to process, I am a quick solution.

I have my name on a few arborists' lists, and every so often I get a call to see if I will take a load of woodchip.

Last week there were multiple crews working along the Great Alpine Road, cutting back high trees to keep the powerlines clear. A device I've not seen before was a round blade, like a sawmill blade, mounted on a pole. The pole was cantilevered upwards and ran in a straight line, slicing off everything in its path. A monstrous tool, noisy and incredibly lethal looking. And following them were chipping crews, cleaning up after the pruning. It was a big job, and they had the big gear out. The truck took a load of 10 cubic metres of chip to fill it.

I was pleased to get a crew call in and ask where I wanted it dumped. I try and make it as easy as I can for them, so I went ahead opening and closing gates, and sent them to the main paddock. (Ideally it should be dumped in the far paddock, where the most damage is, but there is a slippery clay slope and a waterlogged gate to navigate, and getting their truck bogged wouldn't encourage them to come back.) There are remnants of past piles there, and its easy to see where the dump area is. I guess they thought they were being helpful, but they dumped the new chip on top of the old chip. Not ideal, as the old pile had half decomposed and could be used for other things, but still, good to have.

My granddaughter likes climbing to the top of the pile, so I sent her a pic to show the new mountain.

Then the next day, to my delight, another truck pulled in and another 10 metres went on top of the previous dump. The pile was now enormous!

The day after that my granddaughter visited, and we went out to look at the new mountain. Twenty cubic metres of chip dumped on top of an older pile. It spread, of course, but it was at least 2 and a half metres high. Amazing.

Volcanic mountain of woodchip

This pruning was mostly green, more leaves than chips. All the pruning was the upper canopy, it wasn't, say, a felled tree with metres of trunk being chipped. As a result the pile was light, fluffy, and if you stood in it your ankles sank in 20 cm and your boots filled up with chips. That and the towering height, my granddaughter wasn't keen to climb it, so we just stood around and admired it. (Then climbed a smaller, older pile nearby.)

It was a cold day, and it had rained a little bit earlier. As we were looking at the pile I could see steam coming off it, and we discussed it, how the pile would be heating up a bit. I joked that it wasn't a mountain, it was a volcano.

Later that day, after dinner, I took the dogs for a walk and we walked past the chip pile. It was really steaming. In fact, it was generating a LOT of steam that was drifting away in the breeze. I walked over to it and put my hand on the pile. Yeah, sort of warm. I climbed up the pile a bit and where some steam was oozing out of the chips, put my hand on it. Wow. That was more than warm! I scraped away the surface and the steam billowed out. I dug deeper, the chips changing colour from tan, green and brown to grey and white. Some sort of fungal decomposition was fast-tracking the pile, and generating a lot of heat. I dig in further, and almost scalded my hands. The steam was pumping out as I exposed the inside of the pile.

Its been raining, it was going to rain again, I wasn't worried about setting off a bushfire, but if the woodchip pile caught alight I'd never put it out. Its right next to The Scar, the long scrape of a hole that is, at the moment, filled to the brim with raked up autumn leaves. That would also burn for ever if it got going. I scraped off the top metre of the pile and scattered it below, and dug a few holes in the side to expose the hot centre, watched for a little while to see the steam dissipate, then went back home.

But it left me uneasy, and I came back at 10 o'clock at night. The dogs were thrilled with the extra, late-night walk. I brought a small spade. The pile had recovered its mojo and was steaming away furiously.

I worked my way round the pile digging an upward channel every half a metre. I dug down in the pile for each channel until the heat was exposed. The cold air running up the sides drew off the heat. I did actually get out of bed at 2am and look out the window. From our bedroom, in daylight, you can sort of see the pile through the house orchard. But if it had been alight I would have seen it.

Its calmed down now, the last tunneling exercise stopped it and again its been raining enough to dampen any possible fire. I do have plans for the chip. But if I get another dump in the near future, best to start a separate pile, I think!