Pale runner beans

[jillie100]

Hello, I am new to this forum - there seems to be a lot of knowledge and experience here, so I hope someone can help me!

I used to grow a lot of my own veg some 20 years ago, so am not entirely without experience, but definitely rather rusty! This year I felt inspired to try growing some easy crops in my garden here in the Netherlands and among other things I planted some runner beans. I raised them myself from seed (Streamline), and I then planted half the plants in a (new) builders' container (diameter 20", depth approx 12"), with a central pole and hairy string leading up from holes in the side of the container to the top of the pole. I filled the container with compost with the recommended amount of dried cow dung mixed in. The other half of the plants I put into the ground next to the container where I dug in some compost and dried cow dung (about half garden soil, half compost resulting).

This was done on 1st May - early, I know, but our weather was pretty mild. The plants in the container shot up, plenty of leaves, and began flowering about a month ago. The plants in the ground grew much more slowly, but are now at the top of the poles and flowering nicely.

Not many flowers have set, which doesn't bother me too much atm, but what does bother me is that the plants in the container have become very pale yellowy-green, (this began about 3 weeks ago) and now the beans that have set are also going yellow and dropping off! In contrast the plants in the ground are a good green colour and producing their first edible beans! The yellow plants have also stopped growing and flowering.

I read that you shouldn't give beans nitrogen, but a week ago in desperation I did feed them with a general liquid vegetable fertiliser, but I don't see any result. The only other thing I can think of is that the weather in the last week has been very hot, sometimes above 30C, and I wondered if the roots became too hot in the container? I have kept the plants well watered, so I don't think that is an issue.

Has anybody any ideas for me? Do you think the container beans are saveable? I have seen one or two threads in the past about this, but no-one seems to have come back with a solution!

Thanks!

[SarzWix]

I think you might be right about the container plants getting too hot, also they may be suffering from water stress - they really do take up a lot of water and with the container getting so hot, it must be evaporating really quickly. Might be worth trying; some epsom salts in case they're suffering from a lack of magnesium; a large plastic bottle with the bottom cut off, with a couple of holes in the cap, sunk into the middle of the container - fill with water and allow to seep slowly into the soil; feed with tomato food, which is high in potassium needed for flowering and fruiting; wrap the container in something very white to reflect heat.

I don't know if any of those will work, but worth a try?

[Flummery]

You could be right about the hot weather. One thing runners do appreciate is moist soil. That's why we're often advised to dig a trench and fill it with just about anything that will hold moisture - even old newspaper. It's quite possible that your beans ran out of moisture underground or even had their roots cooked. If so, I wouldn't think you'll get anything from them - but they might surprise you. If you can keep them damp again you might get new shoots and new flowers that respond to the better treatment. It could give you a follow-on crop from those in the ground.

Good luck with them - and oh, how rude of me - welcome to The Grapevine!

[Two_Sheds]

French beans cope much better than Runners with heat ... but after the last two summers, how were you to know we'd get a scorcher this year?

[gojiberry]

Water the container well and mulch with a good layer of damp newspawer. This will keep the moisture in and help reduce the sun heating the soil up to much.

Ian

[jillie100]

Thanks!

Thank you for the advice! On reflection the runner bean plants had already begun to become pale and anaemic looking a couple of weeks before last week's heatwave, so I don't think the heat was the cause of the problem, although it might well have stressed out plants that were already struggling....so, luckily, no baked beans!

As I mentioned, a week ago I did give them some liquid fertilizer, and on looking closely yesterday some new shoots are appearing at the leaf nodes that do look a little more green than the old ones. Yesterday I fed the plants with some tomato fertilizer and also removed all the small developing runner beans (a lot were aborting anyway), and the few flowers that were still left. I hope in this way the plants will have a small rest from bean production.

I hadn't realised that beans were such heavy feeders - it does look like they had simply exhausted what was in the garden compost in the container. I hadn't fed them at the same time as the courgettes and tomatoes in containers as I read somewhere (on the net!) that runner beans shouldn't be fed fertilizer with nitrogen in it, and all the liquid fertilizers I can find here seem to have large quantities of nitrogen in their composition. Will this give the plants all they need or is there something better I could feed them with?

Thanks for the tips about heat protection and water conservation, when (or should I say if?) it gets warm again I shall deifinitely try those out. Incredibly the temperature outside is only 13C this morning, when a week ago it wasn't falling under 25C at night...

[Sonata]

I would have thought they were hungry really. Not that my advice is worth anything as I'm a complete beginner. However, I've noticed that when some of my plants are in need of potting on (having exhausted the nutrients in the pot), they go pale..then once I've given them more fresh compost, they soon perk up and romp away.

[SarzWix]

Nitrogen for leafy growth, Potassium for flowers and fruits, Phosphorus for strong roots.
http://www.growfruitandveg.co.uk/gra...nts_14854.html

So if the runners are producing new leaves and shoots, they will need some nitrogen, plus potassium for the flowering and fruiting. I think tomato food will probaly work out best, with maybe a handful or 2 of chicken manure pellets to boost the new growth.

[jillie100]

I thought I would come back to this to update, since others may have the same problems as I had in the future. I fed the plants twice a week with a veggy liquid fertilizer and after a week or so greener veining appeared in the pale leaves, and after about 3 weeks of this they became a healthy green again.

The plants are now flowering profusely and lots of little runner beans have set, so now I just have to keep them fed and watered!

Thanks for the advice, I have now learnt to FEED runner beans in containers in time!