I've been experimenting with trench mulching (as is my habit). My most recent hypothesis was to harness the space between my garden beds as a means to trench mulch my plants.
This requires a bit of lateral thinking. Since I am on sand you need to explore creative ways and means to hang onto the H2O where the plants are at -- near the surface.
So the setup is simple:
- In the middle of the path (over already existing mulch) I lay down a strip of plastic. I cut down old horse feed bags to get my plastic material. It helps to dig a shallow depression in the middle of the pathway as you want the water to accumulate over the plastic and not run off elsewhere. It serves as a gutter.
- On top of this and spread over the whole pathway, not just on top of the plastic, I throw down any twigs, palm fronds, pine cones and banksia pods I can find. Using prunings for this is a great way to put them to immediate use. Any woody stuff will do--so long as it isn't too thick as it will become a navigational hazard. Traffic along the pathway will embed it in the underlying soil over time.
- I then cover the path with a thick layer of wet newspapers. I don't stint on thickness.The thicker the better as I'm trying to create a sponge. The paper layer also smooths over any woody material underneath.
- Atop of that goes a heavy sprinkling of hand fulls of grass clippings.
- The game plan is to every now and then maintain the path by adding another layer of newspapers and a topping of grass clippings (or some other grass mulch). This causes the path to rise and clamber up the garden bed but on sand this doesn't matter as on so much sand, drainage is not always an asset but a frequent handicap.
I've been using a variation of this technique for some time but the addition of the plastic and the woody stuff is an innovation.
To my mind the paths between the beds are going to serve as irrigation channels. Where water is absorbed by the mulches while the plastic layer delays seepage.
Does it work? Since it has only just rained here for the first time in a long time, only time will tell. If I can keep these pathways moist for longer periods I'm hoping that I can irrigate the surrounding soil through capillary action.
In that sense any rain fall is harvested and 'stored' on the pathway by the spongy mix of cut grass, newspaper pulp and woody fibre.Whether I irrigate the pathways instead of -- or as well as -- the garden beds remains to be seen.
Updates will follow as the Summer wet sets in....