Bean breeding & pollination

...indoors on a budget


The following pictures and short videos show the steps to bean pollination (here it was done indoors - no greenhouse needed) in order to create crosses between two varieties.

One can use it as a guide in summer too.

Have your tweezers ready!
 

fleurs de haricot dans la main

For Free:
I believe that knowledge should be shared at a reasonable cost or even free whenever possible. But in this world of ours almost nothing really is completely free. Our tiny seed company is still young and does not provide us with enough funds for both of us yet. Locally, we like to barter first (like getting manure, compost or leaves for seeds or vegetables) but we still have to buy things.

So if you like, feel free to share this web page and our online store to friends who may be interested and help us grow a little. Photos and videos by Hadashah Hétu, 2021, please cite author if using.

Thanks a lot! 
 


Bean Flower Anatomy

The flower bears both male (stamens) and female (pistil, ovaries) parts. Following pollination, the bean pod will develop from the base of the curved pistil which is located inside the keel (a spiral-like structure). The pistil protrudes partially when a slight pressure is applied to the wings, such as when a pollinator lands on the flower.
 

Standard or Banner

Keel

Wings

2fl bean1 before pollination


First, find an immature, unopened flower. (Around 2 days before opening or anthesis). This flower will be pollinated later and develop the pod.
 

3 bean flower hold with tweezers
4fl bean remove standard

The external part is the standard which overlaps the other structures.

5fl bean remove standard2

Remove it slowly to expose the keel and the wings.


 

Video: How to help the pistil to protrude. This one will guide the pollination while inserting the other pollen-coated pistil (next step).

6fl bean flower pistil
7fl pistil sortidetail150.jpg

Pistil (tip of)


Here it is partially exposed.

Now, choose the pollen source. The flower must be freshly opened (same day) and bear mature pollen. Let's remove the pistil from the flower, which should already be coated by its own pollen (bean flowers are normally self-fertile - but crosses can happen in the garden especially when a healthy pollinator population is present).
 

8- bean flower 2
9- bean flower 2


I generally tear off one side of the standard as it helps me reach at the pistil with my tweezers. This step is not absolutely necessary - just seems helpful sometimes.


 

10-bean flower remove standard
11bean flower grab wings

Then grab the wings and pull them down slightly: the pistil should emerge.

Pinch it off and hold it (a bit tricky at first!).

Pollination (next-level tricky):


Identify your cross - simple reminder... which pod is it?
 

forming bean pod after pollination


3-4 days following pollination a small pod is visible. Although successfully formed, remember that a pollination can also occur from its own pollen if the chosen flower had its pollen fertile before that time. (Only the progeny may tell for sure if the pollination was a true cross or a selfing. Depending on the parent varieties, a successful cross can sometimes be visible on the resulting seeds, like a slight (rarely marked) change in seed shape or color pattern - I've seen such changes). In the case no pod forms, you probably got the right technique but the pollen may not have been viable or it did not come into contact with the pistil. Start over...


 

bean pod w 2 seeds_24dap


24 days elapsed after pollination: the pod will be ready soon. Generally a week or so depending on the varieties involved.
 

Seeds from the cross look like the pod-bearing variety.

Here: Seeds from an F1 (from its progeny). The F1 is generally quite uniform unless one or both parents were not stable varieties. Once sown, they give the F2 where variations appear (colors, shapes, yield, etc!) Grow more and select... for the next 6 to 10 years!