Onions and leeks are always the first transplants we seed each year at Seattle Urban Farm Co. (SUFCo). Bulbing onions and leeks have a long growing season, so getting them started early allows for them to grow to maturity in the optimal growing conditions of summer. They also cure better and store longer when harvested during dry weather conditions. Many people devote a large part of their gardens to alliums because they so store well and are very easy to use, so another advantage to a summer harvest is that it can also create room for fall crops!