Runner beans do not grow very well in the far north of scotland so this
year I decided to try growing them in the polytunnel. The plants are
growing very well, in fact I'm not sure whether I should pinch out the
tops to stop them over-growing. My main problem is that the flowers are
not setting any beans. How do I ensure pollination?

Thanks in advance,

Compo in Caithness.

"compo" wrote in message
...
Runner beans do not grow very well in the far north of scotland so this
year I decided to try growing them in the polytunnel. The plants are
growing very well, in fact I'm not sure whether I should pinch out the
tops to stop them over-growing. My main problem is that the flowers are
not setting any beans. How do I ensure pollination?

Thanks in advance,

Compo in Caithness.

It would seem that by growing them in the tunnel you have separated them
from their pollinating insects. Can you open the tunnel up on fine days?
Alternatively, next year I would work out a removable covering to allow
pollination. Maybe a frame that can be fleeced over, something like that.

HTH

Steve

In article , "shazzbat" writes:
|
| "compo" wrote in message
| ...
| Runner beans do not grow very well in the far north of scotland so this
| year I decided to try growing them in the polytunnel. The plants are
| growing very well, in fact I'm not sure whether I should pinch out the
| tops to stop them over-growing. My main problem is that the flowers are
| not setting any beans. How do I ensure pollination?
|
| It would seem that by growing them in the tunnel you have separated them
| from their pollinating insects. Can you open the tunnel up on fine days?
| Alternatively, next year I would work out a removable covering to allow
| pollination. Maybe a frame that can be fleeced over, something like that.

Possibly. A more common cause is too little water or too dry an
atmosphere. They like reasonably high humidity and plenty of
water at the roots (but not waterlogging).


Regards,
Nick Maclaren.

"Nick Maclaren" wrote after:
| "compo" wrote in message
|...
| Runner beans do not grow very well in the far north of scotland so
this
| year I decided to try growing them in the polytunnel. The plants are
| growing very well, in fact I'm not sure whether I should pinch out
the
| tops to stop them over-growing. My main problem is that the flowers
are
| not setting any beans. How do I ensure pollination?
|
| It would seem that by growing them in the tunnel you have separated
them
| from their pollinating insects. Can you open the tunnel up on fine
days?
| Alternatively, next year I would work out a removable covering to allow
| pollination. Maybe a frame that can be fleeced over, something like
that.

Possibly. A more common cause is too little water or too dry an
atmosphere. They like reasonably high humidity and plenty of
water at the roots (but not waterlogging).


A lot of the older gardeners spray their Runners with water every evening,
and swear it helps setting.

--
Regards
Bob
in Runnymede, 17miles west of London, UK

The message
from compo contains these words:

Runner beans do not grow very well in the far north of scotland so this
year I decided to try growing them in the polytunnel. The plants are
growing very well, in fact I'm not sure whether I should pinch out the
tops to stop them over-growing. My main problem is that the flowers are
not setting any beans. How do I ensure pollination?

I find the earliest flowers rarely set. Possibly because they are
lower down on the poles and insects don't find them; or because they
flower before it's quite as warm as they'd like. My runner beans (in the
open) are very behind this cold year, only half way up the canes :-(.

Perhaps there aren't many insects in the tunnel? Keep a door open
during the day if wind permits, and pots or jamjars of marigolds might
help attract insects inside. If none of that works, the traditional
method of hand pollination is a rabbits tail tied on a cane dusted from
flower to flower. Remember you'll have to press the beanflowers' bottom
"lip" to reach the pollen and stamens.

Janet (Isle of Arran).

In message , Nick Maclaren
writes

In article , "shazzbat"
writes:
|
| "compo" wrote in message
| ...
| Runner beans do not grow very well in the far north of scotland so this
| year I decided to try growing them in the polytunnel. The plants are
| growing very well, in fact I'm not sure whether I should pinch out the
| tops to stop them over-growing. My main problem is that the flowers are
| not setting any beans. How do I ensure pollination?
|
| It would seem that by growing them in the tunnel you have separated them
| from their pollinating insects. Can you open the tunnel up on fine days?
| Alternatively, next year I would work out a removable covering to allow
| pollination. Maybe a frame that can be fleeced over, something like that.

Possibly. A more common cause is too little water or too dry an
atmosphere. They like reasonably high humidity and plenty of
water at the roots (but not waterlogging).

I had that problem last year. Lots and lots of flowers but no beans.
Solved by spraying the flowers with water in the late afternoon.

IME it is pretty hard to make a perfect polytunnel that keeps all
insects out - though most of the ones that get in spend their life
bouncing off the roof.

Regards,
--
Martin Brown

Thanks for the tips.

I have already tried misting the plants and the atmosphere is very humid
in the tunnel. The problem may be pollinating insect shortage but I
have read that misting is an acceptable alternative. Perhaps
pollination by hand might be an answer?

--
Cheers,

Compo.

The message
from "Bob Hobden" contains these words:

A lot of the older gardeners spray their Runners with water every evening,
and swear it helps setting.

I think that could be your answer Compo. My Mother taught me that trick
and it worked for her and for us with the exception, for some reason, of the
first few blooms on each plant.

Good Luck ... Jennifer and Edward

In article , (Bob Hobden)
wrote:

A lot of the older gardeners spray their Runners with water every
evening, and swear it helps setting.

Hessayon says "but recent research has shown that the practice of
spraying the flowers is of little value. The best way to avoid trouble
is to grow a white or pink-flowering variety"

Steve Harris - Cheltenham - Real address steve AT netservs DOT com
A useful bit of gardening software at http://www.netservs.com/garden/

In article ,
(Steve Harris) writes:
| In article , (Bob Hobden)
| wrote:
|
| A lot of the older gardeners spray their Runners with water every
| evening, and swear it helps setting.
|
| Hessayon says "but recent research has shown that the practice of
| spraying the flowers is of little value. The best way to avoid trouble
| is to grow a white or pink-flowering variety"

I am pretty certain that the research is unreliable, and what it
should have said is that the practice isn't useful under at least
some realistic circumstances. The same research claimed that the
key was to ensure that they weren't dry at the roots, but I can
witness that doesn't always work, either, if the air is very dry.

What seems to be the case is that runner beans do not set well
if EITHER they are dry at the roots OR if the air is very dry (by
UK standards). It is more often grown for decoration in the USA,
and several Web pages refer to it not setting properly if the
temperature is above 90 Fahrenheit. I suspect that is as much
a relative humidity issue as an absolute temperature one, because
I have tested them with plenty of water at the roots and air
temperatures of 70-80 in the day and lower at night.

Under dry circumstances, French beans (climbing or dwarf) do
much better, but they can't take too much wet. Hence they are
the "common bean" in the USA, whereas the traditional Phaseolus
in the UK is the runner.


Regards,
Nick Maclaren.

The message
from (Nick Maclaren) contains these words:

French beans (climbing or dwarf) do
much better,


I have a batch of climbing French beans (Fothergills Cobra) alongside
the Scaralet Emperor runners. The Frenchies are just beginning to
flower - it will be interesting to see if they set better than the
runners.

--
Cheers,
Compo