Kendall, speaking at the launch of the event in London last week, said: "We are not doing enough. We want British horticulture to be central to (public procurement) and there's a fantastic opportunity."
Sally Scantlebury of the food and drink network Feast - which promotes locally grown food - said that much of the problem lies in the fact that many procurers "do not know about the business of farming".
She added that price is also a pressure as the EU procurement directive requires them to source from the most "economically advantageous" supplier.
She told growers: "It's not easy to do. It does take time but we can get there. The trick is to deal with all of these issues (such as price) and work with (procurers) and keep communicating."
New Covent Garden Market representative Tom Beeston - whose job is to get more food that is grown in the South East into London - added that, in terms of sourcing local produce, caterers are under-performing by 50 per cent.
He said: "They have the demand - every single caterer I see wants more British produce. But they cannot get it. They don't know where to go to find it."
He added: "There needs to be a lot of senior policy work done to break these barriers down. The average caterer does not know where to go."