Warm Season Bean
Most beans are warm season plants. That’s true of the beans most gardeners grow, such as string or snap beans, dry beans and lima beans. You’ll find a wide array of plant types in this group, such as bush, half-runner and pole beans. These beans also come in various colors such as green, yellow, purple, brown, white and streaked and splotched.
Cool Season Beans
Fava beans are the only true cool season bean. They belong to a different family than snap and dry beans, which shows up in their different shape and taste. Sometimes called broad beans or horse beans, they are often grown for animal fodder as well as human consumption. Some people have a genetic metabolic disorder that can cause a blood disorder called favism if they eat fava beans.
With more than 40,000 different bean varieties, gardeners can be overwhelmed with choices. These are readily available:
- Kentucky Wonder – available in pole and bush varieties
- Blue Lake – classic heirloom bean; pole and bush varieties available.
- Royalty Purple Pod – can withstand slightly cooler planting temperatures
- King of the Garden Lima – highly prolific long season pole lima bean.
- Romano – Italian variety available in both green and yellow.
Fava beans are the only bean that can be planted in early spring. Plant them when you plant early peas or lettuce. Late spring is the best time to plant many beans. Beans prefer soil temperatures of 65°F (18° C) to 90°F (32°C), but germinate best with soil temperatures of 80°F (27°C). Use black plastic to warm your soil in cooler springs or short-season areas.
If you have a long season or choose beans with shorter maturity dates, you can plant beans in the summer. Many bush beans are ready in about 60 days. They appreciate the extra warmth of the summer soil and if well-watered, will quickly provide you with a crop. Pole beans, with their longer maturity, are less likely to make a full crop.
If you live in a desert area, you may be able to plant beans with short maturity dates in early fall. Fava beans are often used as a cover crop and can be planted in late fall to winter over. Most beans, however, can’t tolerate fall planting. They are frost sensitive and even if you manage to germinate the seeds, they will not survive long enough to make a good crop.