Although I ordered the potato onions in the spring when I ordered seeds, I knew they would not be shipped until the fall. My shipment arrived right before Labor Day and the bulbs were wrapped in a white plastic netting, along with a 4-page pamphlet on cultural requirements.
According to SESE’s pamphlet, potato onions should be planted in early to mid-November for my Northern Virginia area. Because they are bulbs, it is best to plant them in a well-drained, sandy loam soil with a neutral pH. They are heavy feeders; nitrogen should be applied when leaves are 4-6 inches tall but not during bulb formation. The bulbs should be planted with ½ to 1 inch of soil above the bulbs and a 2-3 inch layer of mulch to control weeds and protect against temperature extremes. Rows should be 6 inches apart. I have not decided where to plant them yet but I know I will have to find a full sun, weed free area that I can water often.
By summer, the bulbs should have grown and divided to produce many more bulbs. Each individual bulb should form a cluster of bulbs at the base, which visible in the shipment I received. After I dig up the bulbs, I have to cure them, and then select the large ones to use in the kitchen, like an onion, and re-plant the smaller ones in the fall (hence perennial). I am looking forward to trying these in the garden and cooking with them next year.