Onion ‘Walla Walla Sweet’

* Common name: Onion ‘Walla Walla Sweet’

* Botanical name: Allium cepa ‘Walla Walla Sweet’

* What it is: One of the best, time-tested onions for the North with mild, sweet flavor and bulbs that can reach almost two pounds. It’s an heirloom variety that has light yellow flesh.

* Size: Strappy leaves grow 10 to 12 inches tall. Bulbs average 4 to 6 inches wide.

* Where to use: Usually grown in vegetable gardens, although they’ll work in any sunny, well drained garden setting. Raised beds are ideal to head off potential rotting. Full sun yields biggest sizes, and low-sulfur soils yield sweetest flavor.

* Care: Plant seed-started transplants or baby “sets” from late March through the end of April. Plants grow best in loose, rich, manure- or compost-enriched soil and with regular moisture. Excess heat and lack of water can make the flavor more pungent, as can high-sulfur soil and fertilizers with sulfates.

Harvest mid-July through August. Cured ‘Walla Walla’ bulbs store in the refrigerator for up to two months.

Cover plants with floating row cover if you run into problems with boring insects such as allium leafminers.

* Great partner: Onions’ spiky form looks nice with the lacy foliage of carrots or the rounded forms of lettuce and cole crops. The oniony scent is also good for repelling bugs from neighboring veggies.