Darling spuds: how to grow potatoes
When it comes to potatoes, I show no restraint. They are one of the easiest things to grow – you put one in and you’re guaranteed to get many back.
I always over-order. I fail to stick to my plan, disregarding what I really have space for, and I can’t help myself if the description says “waxy”, “salad” or “French”. So, once again, I am currently drowning in tubers and eyeing up suitable containers.
Potatoes come in three categories, referring roughly to how long it takes from planting before you get to dig them up: first earlies (100 days), second earlies (120 days) and maincrop (160 days). If you haven’t got your first earlies in, get to it, but the others can be planted in the next two weeks.
I grow many of my early potatoes in bags. I use 16l woven fabric ones – one tuber to a bag – and by the end of June I expect to harvest the majority and be claiming back some of my patio for outdoor life. But any container roughly 30cm x 30cm is fine for a single tuber; anything bigger than 45cm diameter can take two. You can recycle compost bags, use heavy-duty rubble sacks, or punch holes in old tub trugs.
However, maincrop potatoes, for me at least, do better in a sunny position in the ground, where their roots can seek out moisture. That’s my way of saying I can’t keep up with all the watering; if you grow maincrop in pots, be prepared to do a lot of it come July and August, otherwise you’ll get very small potatoes.
Harvest maincrop potatoes when the leaves have gone yellow. If you want them to store well, cut down the foliage and leave for 10 days before digging them up. Allow them to dry before storing. First and second earlies are harvested when the flowers open.
As I practise no-dig maintenance on my plot, I plant the tubers into homemade compost or well-rotted mulch just like you might a bulb; about 7cm deep and roughly 35cm apart. They do best in loose, weed-free soil.
I do this rather than earth up, the process by which you draw soil up around the emerging foliage as it grows. This also protects against late frosts, but I do that by covering the whole patch with enviromesh or fleece, which keeps them warm and helps prevent the soil drying out in spring winds.
Once the threat of frost has passed in April, I whip it off and add extra homemade compost as a mulch throughout the growing season, to prevent the tubers being exposed to light and going green, to suppress weeds and to lock in moisture for lovely, smooth-skinned potatoes.