The thatch was thick and tough to spade. The black, sticky stuff beneath it was even harder to break up. Since it clung to the blade of the hoe, even the cultivator, in big heavy chunks, I figured it might be clay. So I headed down to my favorite garden supplier, who suggested amending with gypsum, which helps loosen clay soils, and mixing in a little black volcanic cinder for better drainage.
But I had a hunch that something else was also going on, so I rang up my favorite UH extension agent, whose family has farmed the Volcano area for generations.
Was that mud really clay? I asked.
"Organic matter," he replied. "You probably have about 6 inches of it."
Apparently, in the Volcano Village area, soil that hasn't been worked in while such as where I live has an impressive layer of organic matter built up over years, composed of composted rainforest leaf litter, ferns and other vegetation. This layer is usually rich in nutrients -- I was thrilled to see so many earthworms feasting on this rainforest "fudge." Farms in the area no longer have this layer; it has long since been broken down and used up through many planting seasons.
Under the organic layer typically is a lighter sandy and/or cindery layer, evidence of the previous volcanic activity from Kilauea volcano. The uncultivated areas of Volcano still have layers upon layers of cinder and ash intact, revealing each period of the thousands of years of volcanic activity in the area. In the Niaulani forest behind the Volcano Art Center, layers have been dated between 1400 to 1650. The undisturbed top layer of the Niaulani old-growth forest, which you walk through while on a very pleasant 1/2 mile trail, has been carbon dated to 200 to 300 years ago.
So. In my backyard I wasn't really dealing with clay per se, but primarily something akin to muck. How was I to break up that stubborn, moist sod? Would gypsum -- which I had already purchased -- help do the trick?
Well, it couldn't hurt, said the extension agent, adding that I should also throw some lime into the mix, since the layer of organic matter usually has a pH of 4 or 5. Acid rain and vog also makes growing conditions highly acidic, so liming the soil with dolomite would also help make the garden more alkaline and better for growing vegetables.
The gypsum wasn't that cheap -- $7 for 5 lbs -- and I had already purchased it, after traveling 30 miles into town to get it. But fortunately I was turning a small area, only 5 feet by 10 feet, and needed only 10 lbs (20-40 lbs per 100 square feet was the recommended application.) I sprinkled it on, came back a few hours later and voila, it did get a little easier to break up the clods. Not by much, but at least I was encouraged to continue the project.
Besides, it was a glorious, sunshiny day in Volcano -- an opportunity too rare to stay inside. While digging up the sweet 'aina I was basking in the splendor of native beauty: Listening to the gravelly call of the 'oma'o. Watching flashes of crimson as the 'apapane flitted through 'ohi'a. Sampling 'ohelo berries, and admiring the delicate half-blossoms of the naupaka kuahiwi.
At some point, work in a garden no longer seems like work, and by the end of the day there's a transformation, even in your own shadow.