Worms

One of the major challenges of gardening in Italy is the super-duper heavy clay soil. In the mountains the problem is pretty much no-soil; most farms up there look like they're growing rocks. But down here in the Tiber valley the soil is really deep. I've dug down to try to find the substrate but it's impossible with just a spade. We are in the flood plain of the Tiber river and the soil is really just silt. It's very good for growing, and has all manner of mineral nutrients, but though it's easy to work in the spring when there has been a lot of rain, it hardens into a dense grey brick in summer, and even in spring if there hasn't been a lot of rain (as there hasn't this year).

It grows the usual staple Italian things quite readily and hardly needs any amending. Aubergine, tomatoes, peas, bush beans, tomatoes, artichokes, tomatoes, finocchio, tomatoes and tomatoes do brilliantly. We have a lot of vineyards around here too, and the climate is good for olives. Also tomatoes.

Onions do well, but other types of less determined root veg really struggle. Carrots, parsnips, beetroot just can't push through the dense soil. So my solution is raised beds and hugelkultur, basically layering composted and fresh organic matter with the clay soil and the compost-soil that comes from Annamaria's 100-year old family compost pile. I also liberally seeded white clover, which is a good green manure and nitrogen-fixer.

Something I've noticed is that when I came the garden was a moonscape. I called it The Big Dry Patch, 200 square meters of compacted clay on which absolutely nothing grew but a few trees. Annamaria's family have worked it for a long time, most of the 20th century, and the standard contadina method is just roto-tilling and planting directly into the ground. This works as a temporary, that is single-season fix, but destroys the soil's natural substructure - all the little tunnels made by worms and beetle grubs and fungus mycelium. So when you till it and then let it settle down, it compacts into a brick, which the sun bakes hard.


When I started digging in it, I hardly ever saw a single worm and there was not a great deal of organic matter in the soil. Since then I've been building raised beds, the floor of which are just the native soil, and there has been an almost miraculous transformation. In just two seasons the moonscape is gone, and there is green everywhere. And everywhere I put a spade in, I'm not only finding worms, but those super-duper big fat ones. In one of the little round raised wattle beds, I was planting pepper plants from the garden centre last summer, and there were so many worms it was difficult to find a clear spot to put a trowel in.



I think I'm going to start vermicomposting next. I have to move next year, and I really want there to be a legacy here of greatly improved soil quality and useability. I'll be very sorry to leave it all, but having a really big garden has provided an opportunity for a kind of graduate course in organic gardening and soil management.



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