Slight departure from my usual political invective — more of a gardening-journal entry, if you can stand it. I try to grow vegetables in a large enclosure on the slopes of the southern Jura mountains. (The enclosure was necessitated by marauding boar, deer and hare.) The land is very mixed forest—over 30 tree species on the property—and the soil, such as it is, tends to be meager and rocky. My garden plot was wrested from a deep sea of bramble. Results have been mixed and unpredictable: corn (maize) has surprisingly been the most consistent performer, when the boar let me have any, whereas zucchini (courgettes) for example, which heretofore had been idiot-proof, last year nearly failed, for no apparent reason. So sometimes do green beans. Some years produce a bounty of basil to the point we tire of fresh pesto; other years it has ailed. Crops would frequently develop yellow leaves or chlorosis, a sign of some nutrient deficiency.
I make my own compost from leaves, twigs, grass cuttings and kitchen waste; artificial fertilizers are eschewed. But I struggle to make enough to enrich a thousand square feet of rocky clay.
Since the mountain is limestone, pebbles of which stud the soil, I figured the soil is alkaline. The question was, how alkaline? Enough to stunt crops and inflict chlorosis? Enough to explain why some crops just won’t thrive? Too much for my presumably acidic compost to buffer? Did it vary from place to place? So in preparation for the current planting season, I splurged on a decent $50 pH gauge, to test all and sundry.
Most parts of the garden have accumulated some layers of my compost over the years. I started by testing a sample from one of those spots. Result: 7.8, on the alkaline side. So, I thought, my compost is not buffering the natural alkalinity very well. Next I found a spot of native soil in a corner of the garden I’d never composted. Result: 6.1. Huh? The native soil is acidic?! Can it be my compost that’s alkaline? Sample from mature compost pile: 7.9. What the hell. Much of the leaves in my compost are oak, which should tend to add acidity. So what’s going on?
Then I remembered that I’ve always added a lot of wood ash to the compost, as we heat with the wood stove. Seems I did too much of a good thing. Ash provides useful minerals, but is also very alkaline. Turns out I should have been adding it only sparingly.
To check, I tested compost from a small pile off to the side to which I’ve never bothered to apply ash. 7.3, much closer to neutral. And then I tested some natural compost from the woods, where some previous owner had made a brush pile ages ago: 5.3, outright acidic. Could I find and sieve enough of that to restore the garden to the slightly acid range most veggies prefer?
In a parallel story, a neighbor runs a large sheep farm, lately changed to cattle. He carts the manure off and sells it commercially. Two years ago I decided to get hold of some, especially since a neighbor in the nearby hamlet had just gotten garden production that was stupendous compared to mine, despite a rocky desolate site, after getting some manure off him. The sheep farmer kindly offered to make me a gift of some sheepshit, but there ensued a drawn-out tale wherein my handyman with a truck could never quite connect with the sheep farmer, who eventually had a bout of bad health and was out of touch for a year…Suffice it to say that as spring 2024 unveiled, I was yet again shit out of luck. So the other day I went to the nearest DIY store and loaded the car with 200kg of commercial horse manure. Manure’s gotta be acidic, I figured, so I expected this would solve my compost pH problem along with the soil’s meagerness.
Or not. Before spreading it, I stuck my trusty pH gauge in: 8.5. You have got to be shitting me. But then, I found on-line advice that says manure indeed tends alkaline, but its ammonia content reacts with soil when spread and produces acids…so it tends to buffer down to at least neutral. Or something like that.
By the way, several years back, once it became clear that climate breakdown would continue to inflict 100-degree summers in these latitudes where 85° used to be a hot summer’s day, I bought a lot of irrigation hose and laid it around the whole garden. Rigged with a timer valve from a tap at the cabin, it moistened the garden all summer long. Now though it occurred to me to check the pH of the cabin’s spring-water supply. 7.6. So my brilliant automated irrigation system has only been keeping the alkalinity too high. No wonder the hops actually did worse in the years since I extended the irrigation to them. (Most crops prefer mildly acidic soil, 6 to 6.5, which helps them absorb nutrients.)
I never much gardened, though I wanted to, until we got this wilderness property eight years ago. I took to it right away. I love fresh veggies, especially things you can’t get in France, like corn on the cob. And I like the challenge of figuring out why things work or don’t. With climate breakdown making civilizational collapse conceivable, and then especially with COVID, growing your own took on a dash of survivalism. (Though I have to say, based on results here I’m glad we don’t have to rely on it. More on that in an upcoming article.)
And I just listened to a podcast interview of George Monbiot, whom I’ve found annoying ever since he pooh-poohed African game parks (many of which I’ve been lucky enough to visit) in a typically killjoy article a while back, but who in this interview makes the good point that we know so little about the soil on which we all depend. (Shout-out to Emily Johnston for the fine interview as part of her “Wild and Beautiful World” podcast.)
So this week’s pH testing makes Monbiot seem right. PH is fundamental to floral performance, but I’ve just found out that you can’t take anything for granted. Night is day, black is white. (Surely the soil in the spruce forest must be acidic? Think again: 7.8. But fifty yards away in the holly grove, 6.2.) You have to consider whether there’s a fundamental parameter you’ve been overlooking, question your assumptions, set aside preconceptions, and get the facts. Then act accordingly. I hope in my case I won’t have to sprinkle iron sulfate to counter the alkalinity that my ashy compost has induced. Before I do anything so rash, I’ll test the garden soil with the recently-spread horse manure tomorrow, now that the manure’s settled in for a day and absorbed some rainfall; maybe the ammonia will have asserted itself.
And my nice new pH gauge has already proven its worth in our little practice-survivalism. (Wouldn’t be a bad idea to include one in those survivalist kits that strapping tattooed men hawk on YouTube, alongside the daggers, lanterns and space blankets.) If it’s half as surprised at these findings as I am, it’s entitled to use the phrase that wifey no longer lets me say, on grounds of alleged vulgarity, but literally true in its case: “Well I’ll be dipped in shit.”