Shelter from the Storm

aldersShelter makes our land energy efficient.

Without shelter vegetables and animals produce less, bees hate the wind so our fruit trees don’t get pollinated, blossoms and fruit get blown off. If we don’t protect ourselves – we use more energy to produce less, simple as that.

Before we can create good shelter, we must understand the winds at our place.

Don’t presume the nor wester arrives at your house directly from the nor west. Wind is fluid, it responds to sand dunes, hills, valleys and buildings. It alters direction, getting funneled into small areas making it colder and stronger. For clues as to your winds look at the shapes of the trees around your place, ask neighbours (the ones with dirt beneath their nails!) and set up wind flags. Strips of rag tied to stakes and banged in round and about are great indicators. Most of all get out in it, and experience it.

Once you understand exactly where all the winds come from then you can set about creating safe havens – little warm sheltered pockets for your food growing enterprises. Start by eliminating cold wind tunnels in those narrow gaps between buildings or beneath tall trees.

Effective wind shelter:

  1. Filters the wind. A solid wall or dense row of trees can create havoc on the otherside as the wind slams up against the solid block and hurls itself over whirling like a dervish. Slat fences and windcloth are excellent examples of filtering not blocking.
  2. Lifts the wind and sends it over the top. Create a ramp with your plantings or by mounding up earth and planting this out. Choose rugged varieties as your first layer of defense. Flaxes or toetoes are fabulous at the bottom of the ‘ramp’, in the brunt of the wind.
  3. Pushes the wind out past the area you want to protect. A semi circle is a really strong shape for a shelterbelt. The outside curve is the windy side and the inside circle the haven. The centre is the point of impact. Layer plants and/or fences and/or windcloth to create three layers at this point. The arms of the semi circle go past the impact of the wind, tapering off to one layer. This shape closes your garden in a warm hug while leaving it open for sunlight.

For every 1metre up count on 6metres protection in front. You don’t need huge trees! The smart gardener chooses trees that match the height they need and avoids the annual hassle of tree trimming. Besides, tall trees can create cold wind funnels underneath. In urban environments stick with low growing, multi branched hedgers like corokia, flax, toetoe, coprosma, rosemary, hebe, muehlenbeckia etc. Fine or rubbery leaves cope best with winds. Use deciduous trees if you need taller specimens to allow winter sun through.

It’s incredible the difference one well placed tree will make.

Get out your pencil and paper and sketch your land and buildings, draw in your winds and then have a play with clever wind solutions before you put in any gardens! Rubbing out mistakes drawn in pencil is a heck of alot easier than rebuilding a garden. It’s the best investment in time you’ll make.

Our new design

The first two layers of our easterly protection are going to consist of Italian Alders dotted (with great thought!) in the pig paddock. Alders send down taproots and are incredibly strong (and fast growing). They survived the last blast 100% in tack – that’s all I need to know! They are not dense (unlike a Karaka or Grisilinea) so filter the wind well; they’re deciduous for winter sun and nitrogen fixing which will benefit the paddock beneath. The third layer will be the berry house which I’ll build along the eastern edge of the vegie patch. The eastern most wall of which will be woven windcloth. I’ll use a white one to let light through.

For more detailed information I recommend Rosemary Morrows book “Earth Users Guide to Permaculture”, her diagrams are really helpful.