This isn't the best of horticultural environments. Soil is thin, stony, poorly drained and acid. Wind and the salt it carries affects all plant growth, winter days are short; long summer days make up for this to some extent. This is extreme gardening. Its much easier to be self-reliant in a warmer, drier, southern climate.
After three seasons of gardening on the margins of the N. Atlantic I realise that a poly-tunnel and a plan are indispensable. The garden "master plan 2012" is based on what I want to eat, how much I want and when I want it. If this self-reliance is going to continue I also need to find out how to keep and store my own seeds as I am totally reliant on a pile of beautifully designed and seductive seed catalogues. These catalogues might not be available after the collapse of the capitalism (financial system), undeniable environmental constraints( climate change and peak oil) and Marx's prediction of class war ( mass shoplifting) all happening sometime during the Olympics.
I want to eat a variety of leaves, legumes and roots throughout the year. This means all year round salads, a range of brassicas, kales, beans, peas and roots. Some of these to be eaten fresh but as all veg growers know you end up eating frozen veg for at least half the year. I only need enough for one except when Dormouse is here, she is a vegetarian and my daughter is even more extreme....a vegan. This means I need to manipulate the plant population in order to get the size of lettuce, broccoli, carrot etc that I want. On the whole none-grain crops (roots, and brassicas) have an asymptotic response to increasing plant population; in other words total yield increases with increasing plant population up to a population where yield stabilises and the individual plants become smaller. Carrot roots, for example, get smaller as population increases beyond a certain point.Forty years ago when I was an Agriculture undergraduate I did my honours dissertation on this! I know what I'm talking about, or at least I did then.
So what is the optimum number of plants per m2 for most purposes when space is at a premium. The answer for some species and varieties is in "Gardening Which" Dec 2011, along with a set of recommended varieties.
Species/variety Plants/m2 Distance w'n row cm Distance b'n plants cm
Cabbage "Red jewel" 9 30 30
Calabrese "Green magic" 9 30 30
Carrots "Early Nantes" 270 2.5 15
Dwarf bean "Speedy" 35 7.5 30
These images of the garden in summer are not really relevant but they cheer me up on a driech day like today.
Finally, yield is not the only criterion when choosing varieties especially potatoes. last year I planted Sarpo Mira maincrop potatoes because of their blight resistance. It seemed to rain continuously in August/September, the potato tops were black with blight and completely trashed but the tubers were clean, they've stored well, and are excellent mashed, boiled, roasted or chipped. Those on the left are "kestrel" a 2nd early lifted at the end of July for the village show.