need help on beans crossing info

[WI_HO_C]

Limas will cross with other limas to some extent, if you grow more than one. Likewise, runner beans will cross with other runner beans. Both are very attractive to bees, and might even cross with limas & runner beans grown by neighbors nearby. However, limas & runner beans will not cross with each other.

As a rule, common beans cross very little. However, Nature is good at breaking rules. I've received beans that were heavily crossed, one about 50%, and one (Jeminez) so badly crossed that I could not identify which plant - if any - was what the original was supposed to look like!

Some varieties may be more prone to crossing. Jeminez may be one of those. I & others have experienced trouble with Goose, and another SSE member has reported trouble with one of his greasy beans.

The number & species of pollinators, and the availability of other pollen & nectar sources may also be factors. Environment may play a role, if it inhibits self-pollination long enough for the flower to open, and to allow fertilization by foreign pollen.

The point is that while crossing between common beans generally occurs at a very low rate, it CAN occur at a high rate under some conditions. Some effort at isolation (by time, distance, barriers, bagging, etc.) should be used if growing several beans, especially if preserving an irreplaceable heirloom. I try to grow different beans a minimum of 30 feet apart, with barrier crops of limas, runner beans, squash, cukes, okra, or annual flowers between them... the method has been highly successful.