The answer to that reveals a hidden assumption to be part of any such definition: geographical location. For example, it could be fruits grown in Asia or South America but which are not grown in Europe (e.g., mangosteen, durian) or common produce in Europe that’s not eaten regularly elsewhere, such as rhubarb or gooseberries.
Another element that ought be included in the definition is time. Sweet (bell) peppers for example were not grown in Canadian glasshouses 30 years ago. Now they’re perhaps the single largest greenhouse food crop, certainly in B.C.
Thirdly, local versus minority demographic groups have a bearing on our definition. Are, for example, Asian vegetables a staple or an alternative to you?
Scale of production should also be considered: other terms (“specialty crops,” “minor crops” or “niche market”) may be more appropriate as they imply limited production volumes. “Exotics” is another term used for such products, but it too is only defined by including the elements just mentioned.
What drives the search? However you chose to define “alternative,’ there are a number of reasons why producers go looking for that ‘something different’ in a greenhouse to give them an edge:
- Extending the sales season with new crops.
- Improving product quality (perhaps compared to field-grown crops).
- Using physical methods for protection from pests and diseases (e.g., can poly-tunnels protect soft fruit from Spotted Wing Drosophila?).
- Growing ‘novel’ crops that need controlled environment growing.
- Meeting customer demand.
- Diversifying produce range, so spreading risk or complementing existing products.
- Achieving the same (or higher) sales figures with lower inputs (better profits) for an “alternative.”
- Providing “local” produce (substituting imports).
- Simply doing it because you want to – enjoying the thrill of growing something other people say you can’t.
Berry fruits have received so much “alternative” focus in recent years, they may now be simply mainstream. I know of at least one grower near Vancouver who has eaten papaya off his own bushes this summer. Could that provide commercial income? And years ago, as a young trainee, I recall trialling glasshouse-grown pepino and babaco (a close relative of papaya). The adventurous among you might want to investigate Korila, Kiwano™, or Cocona although there are hurdles to cross for the bleeding edge growers who try these.
Vegetables aimed at specific demographics of the population may also provide an opportunity. Extra hot peppers (Bhut Johokia, Scotch Bonnets), Okra, Bitter melons, wasabi, cuitlacoche (corn smut), ginger. The list is endless. Choose wisely.
Other groups that might provide options include edible flowers and medicinals (pharmaceuticals) such as sea buckthorn.
Then we can get to the really odd crops that may, just may, have potential for greenhouse production. Stepping out on a limb here, how about rice? Already six acres of sake rice are grown in B.C. – could this be a crop that benefits from protected culture in the future? Current production is done specifically to enable a truly “local” sake to be made in Vancouver. Microalgae are undergoing much research as a potential protected crop, and I heard lately that jeans are now being made from tomato plants. Whatever next?
Closing caution: remember that a niche market product is very vulnerable to even small increases in production area and its effect on price. It doesn’t take much to over-do a niche product. After all, that’s why it’s “alternative.”