As you can tell, these posts are a shared learning experience, with changes for the better always turning up. This year I did a lot of bed building, both for myself, and alongside several clients, resulting in new found tricks to really make a new bed weed free, and productive, fast.
First is the timing. While it is entirely doable to mulch and kill grass at any time of year, I find it easiest done just before the grass breaks dormancy in early spring. It seems to be a vulnerable time for the grass, I assume because it needs sunlight to jump start for the year. In fact mulch laid at this time of year often gets by with no weeding or raking at all.
I also find raking dead grass in spring is much quicker and easier to do than mowing with a scythe. I’ve noticed this is a relatively long lasting mulch -at least as much as green grass mulch, despite its being broken down over winter a little.
So I mow less in fall to leave more grass for mulching in early spring, do less work mulching, and get better results all around.
The idea of long grass I know isn’t attractive to a lot of people. A lot of permaculture designers stress that its not necessary for quality design.
It’s not. But it is far better. Deeper roots, more diversity, more growth, greater stability Through wet and dry wheather are just some of the benefits of letting grass grow tall and harvesting on scheduke like the one I’ve mentioned; but slow growth is better than no-growth. By all means, adapt as your circumstances allow.
Another detail is using bulky, woody material as a base layer –not on top of the mulch. This way it holds the mulch higher off the ground, making that much more space for the weeds underneath to overcome. It also puts the wood where it will hold more water, and so grow more beneficial fungi.
There is no question your mulch will be successful if the weeds are half dead before you even lay the mulch. Putting something completely impenetrable over the ground such as rocks, or logs, as explained in A bit blunt, is probably one of the best findings I made this year. It weakens even pernicious weeds like thistle, and allows for progress to be made while you’re waiting for grass to grow, as I did in the picture above. Every time I got some grass, I would clear as much room as I had grass for, and move the logs onto fresh grass.
Finally, or rather first, have plants propagated and ready for planting. Nature wants to make that site productive. If you don’t, nature will –with the same grass you just cleared. As soon as the plants underneath are dead –probably a week or two after mulching –less if you’ve used logs ahead of time, get that bed planted with mulch makers, fruit bearers, nitrogen fixer, anything you want. Definitely don’t leave the bed empty.
Of course perennials take a long time to grow to full size, so plan on adding fillers such as annual nasturtium or nitrogen fixing peas, beans, or vetch to occupy the gaps until the perennials move in.
With such a good start, it’s wise to build onto a bed rather than start a new detached bed; this conserves your efforts, and allows some leverage of the existing plants.
One way this can be done, as explained in Martin Crawford’s “Creating A Forest Garden” is putting an impenetrable mulch at the edge of a bed whose ground cover is a runner (mint, strawberries, etc. ). This lets the runners grow out, (underneath in the case of mint, on top in the case of strawberries). All the while, the grass is languishing beneath the mulch, so once removed, it allows light to the root runners, earth to the vine runners. The product: instant ground cover.
About the same thing happens with violets. Such as one spot with violets growing among grass, fall aster and others on which I laid a very thick layer of mulch. The grass and everything else were never seen again; the violets, I suppose because they can tolerate very, very deep shade, not so. They broke through!
Of course I am trying hard in other parts of the food forest to establish such a ground cover. So I was more than pleased to see this. But just a note for the reader: violets are not killed by mulch.
And there is my review of bed building for the year. New developments to come I’m sure. Any experience from you, reader, is very welcome in the comments below.