We’ve just planted our second crop of potatoes for the year. At 3450 row ft (about a quarter of an acre), this planting is a bit bigger than our March planting. We aim to grow a whole year’s worth of potatoes for a hundred people. Planting in June has several advantages – for us the main one is that we can store this harvest in a root cellar over the winter, without using any electricity to control temperature. If we planted our whole year’s supply in March, we’d harvest in July and have to store them over the summer, and then all the way round till the next July. It’s also nice to split the work up into smaller chunks.
Up until this spring, we made furrows for our potatoes and covered and hilled them using a BCS 732 rototiller (or walk-behind tractor, as the retailers prefer to designate it). This is doable, but labor-intensive. This year we set up a toolbar on the tractor with sweeps to make furrows, and then discs to form hills. It’s been a learning process, with some teething troubles, but I do think it’s the way of the future for us. (I just don’t have the stamina for all the rototilling any more!).
Compared to using the rototiller, the tractor needs a lot more space to manoeuver. We were lucky in having an area of cover crops next to the potatoes for this planting, so we could run over the edge onto “next door”. In the spring planting, we had a hydrant in the middle of the patch. that’s a minor problem with the rototiller, but a bigger problem with the tractor. Keeping the row spacing tight is harder with the tractor, and in the spring, we ended up with some wider spacings, which lead to more weeds than usual, and poorer hills. This week (our second time using the tractor), we managed much better row spacing. Next year, we’ll allow more space to turn the tractor, right from the planning stage.
Another “surprise feature” this time, was that it rained right after we’d planted (yes, before we’d covered the potatoes). The forecast had suggested a small chance of showers later in the day, but the 3/4″ drenching was a complete surprise! So we had to wait two days for the soil to dry out enough to take the tractor again. The soil was clumpy, but not impossible. Probably we could have covered and hilled sooner with the rototiller, as it weights less, and compacts the soil less. And the soil would have ended up with a finer texture. Overall I think the trade-offfs of using the tractor are worth it.
The potatoes came to no visible harm sitting in their furrow for two days. We had pre-sprouted them, so the sprouts grew a bit bigger and greener. Luckily we didn’t have extremely hot temperatures those days.
Recently I learned some new information about ideal soil temperatures for potato planting. This came from a workshop on Sustainable Potato Production by Rusty Nuffer at Southern SAWG in January 2012. In spring, wait for soil temperatures to reach 50F (10C) before planting. In summer, the ideal soil temperature is 60-75F (15-24C). Ours was 70F (21C). It’s possible to pre-irrigate to lower the soil temperature in summer. (And hopefully nature won’t mid-irrigate for you as it did for us this week!)