With a small garden of 50 sqm, using every square metre of soil productively is critical.
My four bed roation has broadly the following layout:
Bed I: potatoes
Bed II: Broad beans, leeks, beetroot, forcing carrots and lettuce
Bed III: Garlic, Runner beans, french beans, beetroot, June carrots
Bed IV: Parsnip, April and May carrots, onion.
Where space is available, additional salad, turnip, radish and fennel are slotted in for half a season.
This post discusses my root crop bed, how I plan it and why.
I start with parsnips, as these take a whole season to grow. My 2016/17 crop was 4 rows of 1.5m spaced at 40cm, with rows at 20cm, 60cm, 100cm and 140cm from the north end. The crop has yielded 8-12lb/ row and has if anything been slightly more than required for the whole winter. The roots have been up to 40cm long and up to 1.5lb in weight.
As a result, this year, I will only plant three rows, spaced at 20cm, 60cm and 100cm. I will be sowing Tender and True from Real Seeds.
Next I will sow three rows of carrots in early April, spaced at 130cm, 160cm and 190cm. Two rows will be Sweet Candle and one row will be Early Nantes.
Next I will transplant onions: 5 rows of Kelsae spaced at 20cm in an equilateral triangle lattice (220cm, 237.5cm, 255cm, 272.5cm and 290cm); 2 rows of van Rijnsburger clumps (325cm and 350cm latticed); and two rows of van Rijnsburger singles sown at 10cm spacing (370cm and 390cm).
Finally, 5 rows of carrots (Nantes) will be sown in early May (410, 430, 450, 470 and 490cm).
Target yields will be:
April Carrots: 20lb;
May Carrots: 30lb.
In addition, radish will be intersown between parsnip and April Carrots (5 rows) and as an early crop before May carrots (total radish target 5lb). After the onion harvest and April Nantes carrots, autumn salads will be grown (total target 15lb).
As a result, the target for the 7.5 sqm bed for the season will be 150lb.