Friday, June 6, 2014

Gardening on a slope - onion comparison

This post is partly an excuse to get a picture up here, to show something interesting about my hugel bed. 
This is a garden bed built over a pile of logs, which theoretically acts as water storage through dry periods.  This one is probably not big enough to compensate for our 2+ months of summer weather without rainfall, but it does mean I can get away with sporadic (weekly or biweekly) garden attention and still grow some hardy crops.

This is the same bed whose building was described in last spring's post "The Quickening."

It received sporadic watering - usually by me sticking the hose into a vole-hole in the top or side of the bed while weeding, about once every week or two.  But sometimes during our absence, the folks watching the house kindly set up a sprinkler. 

Here's what the onions look like that over-wintered:

Hugel bed showing horseradish (recently released from protective plastic cover because of vole browsing) and onions that over-wintered on sunny side of garden bed.
Approximate heights of onions on the top, middle, and lower parts of the hugel's slope.
So there's this beautiful clear progression in height between the onions on top and bottom of the hugel slope. 
It's possible the difference may reflect the benefits of the shelter and reflected warmth of the bed itself.  On this side, they have protection from NW winds, and also more heat from the sun.  None of the plants are sticking up much above the crown of the bed, even now that spring has arrived with very warm weather).

But I think it's more likely that this reflects the difference in our major limiting growth factor around here, water.  All the onions are in bloom relatively simultaneously; they are the same age and responding to the same seasonal triggers, just different sizes.

The onions at the base of the slope naturally enjoy more water. 

This picture was taken May 11th 2014.  In the three weeks since, that horseradish has of course exploded to a height and volume as big as all three onion plantings combined - its tap roots, like the rhubarb on the far side, give it an extreme advantage to finding deep moisture.