Converting an Apple Orchard to Herbs

I am hoping you will be able to provide some information that will point me in the right direction.
Situation:
We currently have a 5 acre apple orchard. Unfortunately, we can no longer find the help required to maintain the orchard as apples can be imported at a cheaper price. After considerable searching to see what we can do with the orchard, we have decided that we cannot afford to keep it running.
We are now looking at other products that we could grow. We are considering herbs. We live in the Niagara area and have primarily clay soil, with some sandy areas.
Question: What herbs would grow well in this area which are marketable?

Before you abandon the orchard you may want to make sure that you have exhausted all possibilities. Some growers are having good success with value-added products made from farm produce. Because the decision to abandon the orchard involves a cutting down trees that cost a lot to plant and maintain, we feel that the decision should be made only after all possibile revenue streams have been explored.
There are many herbs that grow well in your area. The issue is not so much what will grow in your area, but what can be grown and marketed profitably.
There are many possibilities and a many pitfalls, so it is important to do your homework and study the market side carefully. For example, you may choose to grow and make a value-added product such as a herbal tea, or you may choose to sell fresh-cut herbs to local restaurants – these are but two of many possibilities.
Several books that are highly recommended are Richard Alan Miller's "Getting Started" e-book, Sandie Shore's "Growing and Selling Fresh-cut Herbs" and the book "Medicinal Herbs in the Garden, Field & Marketplace" by Lee Sturdivant and Tim Blakley. All of these titles are available from the Richters website at www.richters.com.

Question: I understand you have a Commercial Farming Workshop in October. Is it open to people who are not in the herb farming business yet?

Absolutely. It is intended for both established herb farmers and for people who are thinking about farming herbs.