12 July, 2014

Gardening with mounds

I was wondering about gardening with mounds. 
I have discussed this before relative to the growing of sweet potatoes on conical mounds as practice norm throughout Melanesia and Polynesia. (See picture at right: that's' a serious mound!)

Since then I built a series of mounds and planted them out with potatoes with the perspective that I had begun to solve my  potato conundrum. 
I fiddled with the setup  and embedded a terracotta irrigator pot in the middle of each mound -- such that the mounds look like volcanoes with craters.
If you are into terracotta pot watering as I am the pot in the middle of a built up conical earth mound is a wondering engineering solution for water spread.It's like a chicken and egg thing . Wonderfully syncronicity. The shape allows not only broader water seepage but enables  more plants to access the irrigating core.

So I not only planted potatoes in the mounds but have since added Zucchini and am considering other options. Between the mounds, in the gullies, I just planted Taro.
However, I am reminded of an earlier gardening inspiration developed by Tiny Eglington.
It blew me away.Check out another example of the design method here ( sample picture at left).
When I laid out my own garden I didn't do this because all I had was sand to work with and going up -- such as for drainage -- didn't seem to make sense.
But that's only part of the story. Much as I tried to make Edlington's watering system work --watering the gullies rather than the beds (deploying a sort of wiking logic) -- I couldn't facilitate it.Not on sand, despite laying plastic and paper and mulch underneath the gullies.
But now that I can water with my pots -- Voila! I have a solution.
Of course gardening in mounds or ridges isn't new. 
HugelKulture is a quintessential mound method (pictured right below). But I've not been able to make HugelKulture work given my conditions. I suspect that here our climate is too dry.
But looking at the 'mound' and reviewing the literature on HK there is a lot of advantages in mounding to that size.
I've thrown a lot of twigs and paper into my mounds --to give them texture and some structural core.I sifted in manures and coated the lot in a blanket of lawn clippings mulch.
Some are a bit like ridges, but double camel hump ridges. I call them '2 pot mounds' as distinct form the conically shaped  'one terracotta pot' mounds.
I'm not certain how far down I should take the gullies. Water pooling doesn't happen here so excavating the gullies is primarily about getting dirt.
Mine are higgledy piggledy things and when I built them it was clear that not only could I water with my fav method -- da pots --  but I could harness the gullies for different purposes such that I could use some, rather than for pathways, as dumps for mulch and cut scrub, newspaper and such like the banana circle option.Even if I walk over this 'rubbish' its' not a problem. As soon as it breaks down I can put it on a garden bed or use it to make another mound.
Indeed these  beds of mine have tended to look like the shape and size of large upturned bathtubs, mini volcanoes or an Alien egg nursery...
But the logic of mounds of this size -- and irrigated as I do -- impresses me.
  • You extend the surface area of your 'bed' by using a curved surface. 
  • Despite the increased size your access to all plants is enhanced because the required reach is less.
  • You harness gravity to encourage plants -- esp ramblers like cucumber, tomatoes and such -- to fall away and down onto a surface that will tend t be drier than a flat bed.
  • You get to also plant in the gullies, esp more water dependent plants. (Thats' the estimate, anyway).
  • Because the mounds are elevated beds -- just like any contour you can plant according to sun requirements -- as you'll have some 'sides' more exposed to the sun than others. So you plant, say, lettuces on the south of the mound and capsicums on the north and west. If planting extensively in the gullies is an option you can use the mounds as shade and or weather protection.
  • Like the Melanesian examples mounds are demountable. That may seem an anathema but it is easy to shift a pile of dirt than dig a hole -- or disassemble a mound and build a new one in its place. Indeed when I began this project I had in mind that the mounds would be my 'portable' garden
How big can these mounds be  given my watering methods? Does the design actually work -- at least on my sandy soils? I'm sure that mounds like this would not suit all soils, as you have to consider erosion issues. But then if you plant out you'd have a underground web on your side. So there's soil run off perhaps? All you do is spade it back up the hill.
Normally, mounding like this would require a lot of precipitation. Conical mounds normally aren't friendly to irrigation systems. But then there's the terracotta pots, you see...and that's a game changer.
Of use: