Green beans are a popular crop for greenhouses especially in the early spring and late fall when the outdoor soil temperature is too low to sprout the seeds. The vining habits of pole-type beans allow them to be trained up to the top of greenhouse spaces and then left to wind their way back down. Although almost all beans will do well in a greenhouse setting, there are several varieties of beans that are particularly suited for greenhouse growing.
Asparagus (Yard Long) Beans
These beans are a fixture in the South where the hot days and warm nights spur this highly productive variety. A greenhouse ensures a stable temperature and enough warm growing days to be able to grow asparagus beans in even the most northern regions of the country. Though called yard long beans, they should be harvested when 12 to 18 inches long for the most tender beans.
Fortex French Pole Bean
Fortex is a long French-style stringless bean that grows longer than most other pole beans (with the exception of asparagus beans). It produces large yields in a greenhouse after 75 days and will continue producing until greenhouse temperatures fall below 45 degrees F for a sustained amount of time. Picking fortex beans daily is important to keep this variety producing.
Bronco is a bush-type green bean that will provide a large crop within a short period of time. The picking season will start approximately 55 days after planting and last for at least a month--not as long as a pole bean but with higher yields. Bronco can also be grown out to maturity, dried and used as a dried bean. It is resistant to molds that sometimes form in greenhouse settings, making it a good candidate for this type of growing.
Louisiana Purple Pod
This unusual heirloom variety of pole bean features purple stems and flowers. Purple 7-inch beans are formed in abundance in 65 days. The beans turn green when cooked and have a delicate flavor similar to French-style pole beans. The color of these bean plants adds interest to a greenhouse. Their delicate growth habit makes a greenhouse the perfect place to try them out.