Potatoes are a most obliging vegetable. Easy to grow, they provide comfort, nutrition, ornamental flowers and multicoloured tubers without making large space demands. Despite the mountains of bagged varieties available in supermarkets, only homegrown kinds retain the fragile, nutty flavours lost in commercial storage. And if your culinary interest ranges beyond the nameless, brown-skinned bakers and boilers, you can grow vivid blue, red and yellow tubers right in your flower beds.
My grandfather grew potatoes alongside his gravel driveway, and though it was only a short row of plants, we had fresh spuds all summer. These plain brown ones never had a name that I knew of, but we always saved enough seed potatoes (not really seeds, but small potatoes about the size of a hen's egg) for planting each spring.
Growing the best spuds
For a jump-start on the season, start seed potatoes indoors. Known as chitting, this is an easy way to get an early crop in the garden.
Three to four weeks before the weather is warm enough to plant outdoors, place the tubers in a wooden flat or in egg cartons with the broad basal end (which has the small remains of a root) down and the "rose" end (where most of the tiny bud sprouts are visible) up. No soil, water or covering is required. Keep them in a dark, dry place. When tiny shoots appear, move the tubers to a cool, bright location (8 to 10˚C, but out of direct sun).
Plant when all danger of frost has passed; choose a site with six to eight hours of full sun each day. Sow early varieties when the soil is at least 6˚C, usually in mid-April (at about the same time as dandelions begin to bloom), and mid- and late-season ones in May.
Although they will grow in all types of soil, potatoes prefer light, well-drained, slightly acidic sandy loam high in organic matter. Amend the soil in planting holes with coarse sand and/or peat moss, leaves or garden compost; avoid manure because it can harbour potential disease-causing organisms.
Plant seed potatoes in a trench roughly 15 to 20 centimetres deep, with the basal end down. If using chits, place them with the sprouts pointing upward and carefully (as the sprouts are brittle) hill up soil around them.
Potatoes need at least 2.5 centimetres of water each week; irrigate the soil, keeping foliage dry. Consistently moist soil with good drainage is important. When plants are 15 centimetres tall, sprinkle a handful (or 250 mL) of granular, low-strength fertilizer such as 7-7-7 around each plant and shallowly scuffle it in with your fingers; additional fertilizer is not needed.
Space early varieties 20 to 25 centimetres apart, mid- and late-season ones 35 to 40 centimetres apart. When the plants are 20 centimetres tall, hill them up with fresh soil, straw, leaves or garden mulch to protect the shallow tubers from light. Hill them up again once they reach 30 centimetres, allowing a thick tuft of leaves to extend from the heaped soil.
Tubers begin forming once the flowers fade and can be picked as needed over several weeks (they will keep growing while in the ground). Early varieties can be dug throughout June, while mid- and late-season ones can be harvested from August through late September. For potatoes day-to-day, use your hands or a trowel to dig around the skirt of each plant for the smallest tubers and break them off. Replace the disturbed soil and water the plant immediately to prevent it from wilting.
To harvest potatoes for winter storage, wait until the leaves and stems have died down and are semi-dry. Use a garden fork to gently up-end each plant; cut tubers from the roots and let them air-dry in the shade on a cloth sack or wooden board for several hours. Then move them to a dark, well-ventilated place indoors for further curing over 10 days.
Although early-season potatoes don't store well, mid- and late-season varieties will keep all winter. When tubers are fully cured, they will store without sprouting for several months in complete darkness at 4 to 7˚C, in a slightly humid environment. A basement refrigerator set at the appropriate temperature is ideal. A box of moist sand or sawdust in an unheated basement can also work well. Be sure to save the smaller tubers for next spring's seed potatoes.