To dig or not to dig?
As late autumn or winter is possibly the best time of year to create a new bed (for one thing there is little else going on in the garden), some of you may be thinking along those lines and be interested in the results of our no-dig 'experiment'.
Like everyone else, we're increasingly aware of the need to support and nurture the soil so last year, when we wanted to create a new bed, we decided to give the no-dig method a try. Essentially, this is how we went about it:
we covered the area of the would-be bed with thick cardboard
then covered that with a 10cm deep layer of compost
topped this off with bark mulch (about 5cm deep)
and left it for 6 months.
The theory was that this would block light to the grass and weeds underneath, eventually killing them off, while also feeding the soil food web. The mulch is added to insulate the soil and protect the compost from wind and rain erosion as well as heavy rain compaction. It also looks nice!
We started collecting cardboard in late summer. It was much easier than I anticipated to gather enough; friends, neighbours and local garden centres all donated generously (we were very fortunate that we got new neighbours that autumn, happy to be relieved of their packing boxes - I suspect they think I'm a bit eccentric). In fact, we gathered so much cardboard we decided to create not one new bed but three. Removing the sellotape from the boxes proved incredibly boring and took forever.
Sellotape removal complete, our 'lasagna' beds were constructed in November 2021. So, a year on, what is our verdict?
Well, I'm delighted to report that two of the beds were an overwhelming success (I'll come on to the third in a minute). Although they were ready to plant into in the spring, the beds are still pretty sparsely populated (I'm going to add bulbs this autumn). Despite the lack of ground-cover, the beds remained virtually – miraculously - weed free for a year. The shrubs that were already in place have really taken off, despite a difficult summer, fed by the compost and untrammelled by the scrubby grass that previously surrounded them. The herbaceous planting coped with the drought much better than elsewhere in the garden. All good then.
So, the third bed. Unfortunately, it has become infested with Creeping Cinquefoil which is proving a 'challenge' to try and control. It was no doubt already present but, in eradicating the grass and other weeds, we have clearly created perfect conditions for it to thrive. With hindsight, I made a rookie error. Partway through creating this bed, life and the weather got in the way so that we only got some of the compost in place before leaving it for a few weeks. We topped this up later but I suspect that the wretched Cinquefoil needed the thick cardboard and full 15cm of compost + bark treatment in one hit to stop it in its tracks. Lesson learned. Not, then, a failure of 'no-dig'.
Despite this set-back, I am totally converted to no-dig methodology. The benefits to soil ecology are well rehearsed but, additionally, we saved ourselves a huge amount of back-breaking work, not to mention the need to dispose of, or otherwise lose, a lot of weed-ridden turf. There was a financial cost to it, of course. We didn't have enough of our home-made compost and had to buy more together with bark for mulching but then creating beds by traditional digging isn't free either as a mulch of some kind is needed. In my view, done properly, with a good layer of cardboard and the recommended thickness of compost, it really does work a treat.