Roof Top Veges

"What's that on top of your garage??!" is a FAQ for us.  A wood pile?  Storage units?  Coffins?  With a garden that lacks sun in winter, we began looking for the sunniest spots to grow veges in.  It soon became clear that the garage roof was begging to be grown on, so our roof top vege garden came into being.


Amazingly, our old corrugated iron garage had withstood the 7.4 magnitude earthquake that hit Christchurch in September 2010, yet we wondered whether it could hold the weight of 3 large planter boxes.  We spotted some bits of wood that would make perfect beams to strengthen the roof at the local swimming pool which had collapsed in the quake, so under cover of darkness they made their way back to our place.

The extra beams added to strengthen the roof.  Thanks Swimming Pool!

Ollie quickly nailed together the boxes, and once up on the roof we put some strongish flat boards underneath.  Water retention was always going to be an issue, so we lined the boxes with sheets of thick plastic with a few holes poked in to allow some drainage.

Then came the tricky matter of what to fill them up with.  Everything I'd read talked about layering pea straw with compost.  We didn't have pea straw, and not much compost, so this required a bit of lateral thinking.  Luckily the council had just cut the long grass of the river banks across the road from our place, so we got out the wheelbarrow & gathered up the grass.  First we laid down a 30 - 40cm layer of thin sticks / old prunings, then alternating layers of grass and horsepoo, topped off with some compost.  Voila!

We made the boxes at the end of summer (March 2011), so the first veges to be planted were winter greens - kale, broccoli, spinach, and some strawberry plants.  They absolutely flourished in the warmth up there.

Safe and easy access to your roof is obviously a winner.  We just rest our ladder against the side of the garage.  The safety of the system was tested in July 2011 when another big earthquake struck.  This one was a 6.2 and I happened to be on the roof admiring the veges.  Rooftop gardening turned into surfing, as
the whole building shook violently and all the trees around swayed like a hurricane was passing through.  A big stack of wood leaning against the garage fell over and hit the ladder, threatening to knock it over, and I began to wonder how I'd get down.  Happily I made it back to ground in one piece.

January 2012 - The boxes are now planted up with cherry tomatoes on the left, zucchinis and cucumbers in the middle, and the third one is empty, having just harvested the garlic.

The tomatoes and zucchinis are doing really well in the warmth.  There's a thick layer of mulch to help keep in moisture, but they certainly welcome extra water.  It's been too hot for the strawberry plants up there, and I think the cucumbers need more water than I remember to give them.

So, after several thousand earthquakes, the garage and roof top boxes are still standing strong while our house has to be demolished :)