Seed potatoes are traditionally planted out on Easter Monday. I put mine in last week, and only because my head gardener put hers in the week before. Global warming shifts surprising areas of our lives. Each year I've grown two earlies (one a salad potato), and one variety of main crop. And each year, after the first couple of weeks digging up and boiling the first new potatoes, our appetites for these little treasures fade, and I'm left with a row or two that simply gets forgotten. This year I'm determined to grow just one variety of main crop, and one new potato. "New potato" means the same as "first earlies," that is, the first potato varieties ready for harvesting in the growing season, usually around about May or June / 10 weeks after planting. The next lot of potatoes ready for harvesting are called "second earlies"; and then the main crop potatoes are ready to be dug, having been in the ground long enough for most of the sugars to turn to starch, harvested after about twenty weeks . Less sweet than the first new potatoes, they are none the less the most flavoursome, lasting well into late winter in storage.
I planted out 6 rows of King Edward, and because I left it too late to buy my preferred choice, International Kidney, my new potato is Swift.
Of course I know to double dig the ground, mixing the trough with well-rotted manure, then plant the seed potatoes or tubers at 12" (new potatoes) or 18" (main crop) distance apart in the row, with between 2' (new potatoes) or 2.5' (main crop) distance between rows. Then you have to earth up the haulms (the green leafy bits that grow from the tubers) as they reach through the soil, until by harvest time you have row upon row of Toblerone-like earthworks. Too much work my dears! Last year I dug an individual hole for each tuber, dropped it in, back filled with my spade and moved on down the row. Earthed them up as normal, and they gave as good a crop as ever. This year I'm moving even less soil, and used my bulb planter to take out a deep hole and dropped the tuber in. So let's see if all that digging of trenches does make any difference to yield. I suppose trenches were dug to loosen up the surrounding soil to enable the tubers to grow and swell; spring ploughing a week or two before planting does the same trick. And having read an article a few years ago debating the "to chit or not to chit" question, and reading that commercial growers never bother to chit, I experienced a horticultural epiphany of sorts, and abandoned chitting seed potatoes altogether. So let's see if my laziness / scientific approach to evidenced based horticulture works.
Potato Harvesting, Carl Larsson