Carryover Seed Explained: Certified, Tested, and More Valuable Than Ever

From bumper crops to insurance against bad harvests, carryover seed plays a bigger role than many people realize.

Carryover seed is becoming a more visible part of the Alberta seed landscape, but according to seed growers and testing experts, its presence is nothing new. In fact, having carryover seed on hand often presents a strategic advantage for both seed growers and farmers.

The Alberta-British Columbia Seed Growers’ Association (ABCSG) has offered a carryover listing service since around 2009, before the Canadian Seed Growers’ Association (CSGA) added carryover capability to the national Seed Locator in 2018.

For Greg Stamp of Stamp Seeds, carryover seed — certified seed that simply wasn’t sold the year it was produced — is a natural part of running a pedigreed seed business. Predicting dryland yields isn’t exact, he says, and some years he produces more seed than expected.

“Sometimes we expect 20 bushels of durum and get 40 or 50,” he says. “That becomes two years’ worth. We’re selling that crop across two seasons.”

Demand can shift just as unpredictably as yield. A variety that sells quickly one year may stall the next. In both cases, carryover seed remains certified and fully tested, but seed growers must make sure buyers are aware it exists.

Morgan Webb, president of Seed Check, agrees that carryover isn’t always a sign something went wrong in the marketplace — often it’s simply a result of high-quality bumper years, or a cyclical oversupply in crops like alfalfa, timothy or turf species. In years of poor harvest quality, having old-crop inventory can even be an insurance policy.