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Produce => Edible Plants => Topic started by: Silverleaf on August 29, 2014, 16:32:55
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So my first ever runners went in this year, and they've mostly grown quite well. Some are 7-8' and they now have a lot of flowers.
They went in late so they are way behind what is usual, but I thought I'd get a crop out of them and bulk up my seed a bit as well. I'm starting two landraces - one for pods and one for beans.
But I was worried, because flowers grew and opened and looked pretty and the withered and fell off. No pods. There are a lot of bees here but they seem to be very busy with the nasturtiums and the honeysuckle and the last bramble flowers and the radishes I let flower for the insects and the mispoona I'm hopefully saving seed from. I haven't seen anything more than a very occasional hoverfly on the runners, and they didn't seem to be actually feeding on the flowers. I was getting worried.
8 hours ago I checked the plants: no pods. Nothing at all. Even though the RHS say that spraying the flowers with water doesn't do anything, I was almost desperate enough to try it just to feel like I was doing something!
And then this afternoon there are loads of tiny hairy little pods almost mocking me, as if they'd been there all along... so yay, I get to finally try them, with any luck. :) And hopefully they'll be crossing away like mad for me to get my landraces started properly. :icon_cheers:
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I find they do seem to set better when it rains.
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Hmm. They didn't bother a couple of weeks ago when it was chucking it down, and it's not rained very much since. I've no idea what's going on!
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Hmm. They didn't bother a couple of weeks ago when it was chucking it down, and it's not rained very much since. I've no idea what's going on!
Little drops of rain, just jiggling the runner beans into setting, rather than a drowning deluge which does the pollen no good perhaps?
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Hmm. They didn't bother a couple of weeks ago when it was chucking it down, and it's not rained very much since. I've no idea what's going on!
Little drops of rain, just jiggling the runner beans into setting, rather than a drowning deluge which does the pollen no good perhaps?
That makes sense.
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I grow some runners in a poly-tunnel most years and they do seem to set well enough, except for when the temperatures get much too hot. No rain helping with pollination but they do like their roots to be kept moist. Sometimes they can be a bit picky about setting pods, though it isn't always obvious why - I just think they like to be bit quirky at times!
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Well whatever has been stopping pollination, and whatever has made it actually happen, has affected all my plants (which are in three different areas) at exactly the same time, despite slight differences in flowering times.
So I guess it's an environmental thing. Two patches (my little "eating" bed and a big pot of beans for seed saving) are right next to plants that bees love, while the other seed saving pot doesn't have anything really close that attracts bees. All three have pollinated flowers so proximity to bee plants doesn't seem to be a factor here.
They seem to have just been messing about for weeks procrastinating and now they've decided to get on with the job properly. And I'm very grateful!
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Another problem with the flowers falling off beans can be what I call back door bees. These are small type of bumble bees that instead of going into the front of the beans they drill a hole in the back of the flower and take the nectar without pollinating the flower. Then all the other bees use the back door, finally the flower falls off and there are no beans.
Using a feather or paint brush to pollenate can also help.
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I watched that BBC programme on bees and apparently bees give off positive electrods and flowers negative and when a bee visits a flower to take the nectare the flower visited then becomes positive so the next bee knows that flower doesn't have any pollen so moves to a negative flower that does. After a while the flower visited replenishes its nectare and then becomes negative again.
It sounds as though you've just had bad luck because we've had so many runner beans and dwarf beans this year that we picked 8 lbs and froze it all. This made 28 bags of beans and now we've got butternot squash to contend with.
We grew Tumbling Tom tomatoes in a grow bag and it too looked like there weren't any bees visiting the flowers. So I got my make up brush and cross brushed all the flowers in case the bees didn't turn up and now we have over 100 tomatoes forming on the plants. Some of them might have been my cross-pollination but the bees also took part as they did eventually visit the flowers.
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Another problem with the flowers falling off beans can be what I call back door bees. These are small type of bumble bees that instead of going into the front of the beans they drill a hole in the back of the flower and take the nectar without pollinating the flower. Then all the other bees use the back door, finally the flower falls off and there are no beans.
Using a feather or paint brush to pollenate can also help.
I sat for several hours the other week right by the runner beans, watching many hover flies and honey bees and several species of bumblebee feeding on the nearby flowering brassicas and radishes. Not one went anywhere near the beans. Maybe they've changed their preferences this week and decided they like them after all?
I didn't see any signs of damaged flowers.
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We grew Tumbling Tom tomatoes in a grow bag and it too looked like there weren't any bees visiting the flowers. So I got my make up brush and cross brushed all the flowers in case the bees didn't turn up and now we have over 100 tomatoes forming on the plants. Some of them might have been my cross-pollination but the bees also took part as they did eventually visit the flowers.
Tomatoes usually self-pollinate so they don't need bees. Bees can help by vibrating the flower so more pollen falls on the stigma, but you can get the same effect by simply tapping the plants.
The pollen is mostly shed inside the fused anther cone so I'm not sure how much help a brush would be - probably the shaking of the flower was what did it.
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I did not have that many flowers on my runners and so I am not surprised that I have not had any fruit, or next to nothing in any case. there is still young growth on them, is there any chance of beans at this late stage or am I better of just ripping them out now?
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I did not have that many flowers on my runners and so I am not surprised that I have not had any fruit, or next to nothing in any case. there is still young growth on them, is there any chance of beans at this late stage or am I better of just ripping them out now?
Definitely leave them in! Give them a good dose of liquid fertiliser and a lot of water, then stand back. Well that should work in theory anyway. Good luck. :wave:
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it's high temperatures, particularly at night, that cause the flowers or developing pods to drop off or abscise, so they should start producing now
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Stood for 5 minutes just now watching runner beans, and spotted two honey bees and a tree bumblebee busy pollinating the flowers for me, along with a few hoverflies apparently "supervising"! The bumble looked too big to fit in the flowers and I was wondering if it would bite into the base of them, but it crammed itself in with its big furry bum sticking out of the side.
Tiny beans are close to an inch long now. Keep going bees, I need those seeds for next year... and of course a few to sample myself too. :)