When choosing which onion to grow, be aware of the day length the onion requires. The day length for this area is considered a Long day or an Intermediate day. Short day varieties may be grown in this area, but they won’t perform as well as they would in the southern part of the country. Onions should be planted six weeks before the last frost date. The estimated last frost date for this area is May 21
Onions prefer fertile, well-balanced soil, and lots of light. A soil pH of 5.5 to 6.5 is considered ideal for onions. Adding composted manure and other composted materials will help where clay or heavy soils are involved. This should be done two weeks prior to planting and even better, if done the fall before planting. Onions have two major growing steps. The first is the growing of the top and the roots. The second is the bulb formation. The secret to growing onions is to grow the tops as large and as quick as possible, for the bulb below will not get any larger the top. Foliar feeding as well as soil feeding can encourage this.
Mays Greenhouse ©2010