And the same is true of tomatoes - minimal crossing occurs - usually reported at less than 5% - because they self-pollinate even closed blossoms. Dave

Ditto on Farmerdilla's comments. When we in the U.S. say "pole beans", "bush beans", "green beans", or "snap beans", we are generally referring to P. vulgaris. I often refer to them as "common beans", which is an English translation of the Latin vulgaris. In the U.K., they would be referred to as "French beans". Runner beans (P. coccineus) are mostly climbers, hence the name. There are only a few bush varieties. They are also good as snaps... in fact, "snap beans" in the U.K. are almost always runner beans. As Farmerdilla mentioned, runner beans thrive in cooler weather, where common beans struggle. In the U.S. they do well in the Pacific Northwest and areas with cool maritime climate. They do not like hot weather, so common beans are better for areas with warm summers. Some runner beans (especially white-seeded ones) are often misidentified as common beans or limas. When in doubt, observe the cotyledons (the seed halves). For runner beans, these stay below the ground during germination. The cotyledons emerge for common beans & limas.

Annette - Thanks for the info. Jim - Reason for my "string search": One of the biggest problems I have been having regarding creating a comprehensive list of bean varieties is finding out that I have a bean variety in the stringless "snap" category that is in fact a stringed variety. I think folks would really be disappointed or get upset if, upon using the list as a guide, they acquire and grow a bean variety they thought was a snap bean but it turns out to have strings (it would upset me, especially if it was planted for my main crop). This is why I would appreciate greatly if sources better described their bean varieties. I have come across many retail online and hard-copy seed catalogs that mix in heirloom stringed varieties with stringless varieties and the fact they have strings is not mentioned in the descriptions. They just lump everything together in their "green beans" category. I really dislike the confusing term "snap" relating to beans. I know not all beans are "snap" beans, yet it seems like half the people now use that term for any bush, pole, or runner bean in which the pod is consumed (with some exceptions). The other half (generally older gardeners) still use the term "string bean" for any bush, pole, or runner bean in which the pod is consumed. From my research it is my understanding that the term "snap" was coined specifically as a promotional tool for selling what was then the new rounded stringless bush bean varieties. The term then became standardized for any rounded stringless bush or pole varieties. If that is correct then there is technically no such thing as a stringed snap bean. True?

My own preferences are much the same as Hemnancy's; I prefer pole beans for their size, flavor, and yield... and for the enormous variation available in heirloom varieties. They require more space, but that is not an issue for me. Bush beans, however, have their advantages too... so sometimes (preferences aside) it's a question of which type is most suitable for the location & the intended purpose. It's also worth noting that beans should be considered for more than just snaps. Bush beans Advantages: - Easy to plant, require no support. - They mature more quickly. This makes them better suited for short-season areas, for late planting, and when they will be grown early or late as part of a succession planting. - Generally bear all-at-once, so good if grown for canning in large batches, especially with limited space. - Low profile, so better suited for high-wind areas. - Most popular dry beans are bush varieties. - More wax bean varieties available commercially as bush than as pole. Disadvantages: - Less suitable for kitchen gardens, where a prolonged harvest is preferable. Succession planting every few weeks can overcome this, if space is available to do so. - More vulnerable to damage by slugs and rodents. - Lower yield.* - Generally smaller pod size. - Fewer cultivars available for use as shellies. - Harvest can be uncomfortable, due to constant bending. Pole beans Advantages: - Higher yield*, sometimes enormous. - Generally larger pods as snaps, so less cutting involved for canning. - More varieties available for shellies, including most of the larger-seeded. - Prolonged harvest, good for fresh eating over a long period. Some varieties, though, will have large flushes in a relatively short period of time. - Pods are higher, making them easy to see & pick, with minimal bending. - Less damage from rodents, snails, & crawling insects. Disadvantages: - Require erecting a pole/trellis. Not too tough for a 20-foot row, but 500 feet of trellis can be a chore. - Take longer to bear, making them less suitable for short season areas. (There are, however, fast-maturing varieties like "Goldmarie" and "Early Riser"). - Except for very long-season areas, they occupy the ground for the entire season, so not suitable for succession planting. - Not good for high-wind areas, where poles & vines may be snapped. - While the over-all yield is very high, the yield-per-plant for a given period may be relatively low, so smaller daily pickings. This is only an issue where space is limited. - Few varieties commercially available for dry beans (but many heirlooms). I have also observed that many bean diseases are either caused or aggravated by soil being splashed on the leaves; bush beans seem to be more vulnerable to this. I used the (*) for yield, because with different planting strategies, either bush or pole can be high-yielding: - Pole varieties have a higher yield per plant, and often the highest yield per row foot... but much of this advantage is lost with multiple rows, because of the greater row spacing required due to shading. They are at their best if planted in a single row, at the North side of the garden. My largest yield per row by far was from a row of "Pole 191" snap beans. - Bush varieties, while yielding less per plant, can be spaced more closely... and since shade is not an issue, the rows can be closer together as well. Succession planting can also help overcome the yield gap, since it allows bush beans to time-share a given space with another crop. I think that the best bean strategy is a single row of pole beans on the North side - with a row or two of bush beans directly adjacent on the South side - so as to form one wide row. This gives the best of both worlds, in a relatively small space. Those pole beans, by the way, can include limas or yardlong beans. As for strings, I think there is little difference; there are both pole beans & bush beans, with- and without strings. However, since most breeding going on now is for bush beans, there will eventually be more stringless varieties available as bush. I don't necessarily see "stringlessness" as an advantage, since many varieties that develop strings are stringless when picked young, and have outstanding flavor. "Kentucky Wonder" is a great example of this. Most of the new bush varieties, while stringless, are of the petite style now popular in Europe... takes a lot of picking to get a basket full. No thank you. Give me the 11" pods of "Fortex", or the long pods of "Goldmarie" or "Garafal Oro", any day.