Growing in Clay Soil – Diary of a Rocket Gardener

I had thought to write a bit about using bamboo to build fences this week, but since the storms blew mine to pieces, I decided on a different subject! I have been mulling over the changes in my own approach to growing veg over the past few years, and one thing that I have learnt is how to grow well in clay soil, such is the nature of my plot – a south-facing slope with fairly clumpy clay soil.

If you have clay soil, don’t let it put you off growing. That’s the first thing I want to say. In my first two years of growing, I did well even without mulching. Back then, I just dug over the soil as well as I could before planting. Everything was fine, even potatoes grew well. I had to water thoroughly several times a week because the soil would dry up so easily, and I had a lot of weeds to contend with, but other than that, it was fine.

What I have learnt since is that there are a few things that can be done to make growing in clay soil a little less labour intensive. Here’s my list of ideas:

  1. Raised beds are brilliant: Where I have planted straight into the ground, without building raised beds, the soil has been heavier, and has tended to get more waterlogged in wet weather and more cracked in dry weather.
  2. Add compost when planting. Just throwing a handful of compost into the holes before planting the seedlings helps them to get their roots down I think. Then by the time the roots hit the clay soil, the plants already have a solid structure, and off they go!
  3. Mulch: By covering beds with a thick layer of mulch, I have managed to reduce the need to water when it is dry and it is so much easier to keep on top of weeds. I just spread compost over the top of beds, and I also use Strulch (a branded mulch that you can order online). I eventually moved to ‘no-dig’, meaning I no longer dig over beds, but simply mulch heavily each season and allow nature to work the soil below the mulch. The soil consistency is slowly evolving, and less heavy than it used to be.
  4. Grow roots in trenches: Before moving to no dig, this worked well for parsnips, carrots and potatoes. I would dig a trench, fill it with compost, and plant the roots into the compost. That way, they didn’t have to contend with lumps in the soil and were a little less wonky.
  5. Grow brassicas: I’ve always found brassicas do really well in the clay soil in my plot. I think it is because they can be firmed in so well, which helps them to form tighter heads and stops the taller plants, like sprouts and broccoli and cavolo nero, from rocking in the winds.