Runner bean leaves turning yellow

[Piglet6]

I have 3 runner bean plants and the bottom leaves on one of them have turned yellow.

Wondered if anyone could tell me why this is please?

TIA

[Monika]

Sounds as if they may be too wet at the roots or it's been too cold with you for runner beans outside.
Hopefully, you did not use aminopyralid-affected manure in the ground?
If the rest of the plant is ok, they may recover fully before they start flowering.

[glallotments]

If it was ap in the manure the leaves would be stunted, curled upwards and leathery. The veins are prominent and seem to run in parallel lines rather than out towards the edges of the leave.

If the runner beans were planted inside and then transferred outdoors I'd guess that the cold has affected them. Did you harden them off before planting out?

[Piglet6]

They went straight in the flower bed without any kind of compost, so it can't be that, I don't think.

I've been keeping them watered so maybe it is getting a bit too much.

Yes, they've been thoroughly hardened off.

Gave them a feed this morning to try and perk that one plant up.

Thank you for your suggestions. I'm relying on you guys to help me along my steep learning-curve this year (& next, etc etc)

[oldherbaceous]

Dear Piglet6, i think the yellowing of the leaves might well have been down to over-watering.

I normally give any new plants a good drink when planted, then no more until they start growing away.
The only time i will give them a litte more is, if it's exceptionally hot or windy and they show signs of drooping slightly.

The trouble with constantly soaking plants is, it tends to rot the new roots, so the plants struggle to get going.

An easy way to see how this works is, to prick out, or pot on two plants, keep one heavily watered and one nearly dry. After a few weeks tip both the plants out of their pots, the drier one will be full of roots, but the wet one with have very little root growth.

[Primrose]

Thanks for that tip OH - the question of root growth versus amount of watering was not one I was aware of so I'll try to bear this is mind in future. One always tends to be more alert to what's happening above the soil where you can see it, rather than beneath it. There's always something new to learn on this forum!

[Piglet6]

Thanks OH. I'll allow them to dry out a little. They are pretty established, however. The 2 healthiest ones are approx 4' tall.

[Johnboy]

Hi OH,
I agree entirely with your posting and for this reason I do not mulch Runner Beans because I suspect that mulching encourages plants to make roots too near to the surface and this can be disastrous.
Best left to search water out for themselves when the radical will eventually be a couple of feet at least below the surface.
When the beans are well established and producing plenty of beans then I do give them a daily water. I have a manual irrigation system and they get five minutes per day depending on the weather. If rain is forecast then no water is used at all. The watering only really commences when the beans have reached maturity in other works right up the trellis.
JB.

[Piglet6]

Interesting comments JB. I'll leave them to their own devices for a while then, I think. And start watering them a little each day when producing. Thanks.