In theory, conservation procurement auctions can cost-effectively allocate payments-for-ecosystem-services (PES) contracts by allocating funding to projects that provide the most benefit per dollar spent. In reality, auctions only succeed if many farmers choose to submit bids so that the auctioneer can evaluate numerous projects for targeted funding. Reflecting on outcomes from two real auctions in the Western Lake Erie Basin, we identify factors that impede participation in conservation procurement auctions. Farmland rental agreements limited landowner participation for nearly 25% of respondents because renters made the agricultural management decisions. Auction complexity was another key deterrent because landowners did not want to spend time and energy learning about the program. Many landowners were generally confused about the auction despite numerous resources available to assist them during the bidding process. Simple programs that target vulnerable lands and engage renters are needed. Our results can inform the design of future programs to increase participation and cost-effectively enhance ecosystem services in agricultural landscapes.