is this sunscald on French bean leaves?

[Karen]

Hi Charles,

Any idea what causes this to happen to some of my French bean leaves? It seems to happen off and on every year. Is it sunscald?

The current outside temperatures is about 35 degrees and the polytunnel temp with the shade cloth is 38 degrees! Hot Hot Hot and Humid!

[charles]

Yes Karen I think its about heat being too much so plants cannot access water fast enough. I had a little on early French beans in the greenhouse, they are fine now.

[Karen]

ok thanks… may have to re-sow another batch if they don’t survive.

[Karen]

Is anyone having similar problems with their French beans or Bush beans?

Strangely none of my Czar beans have this problem… ONLY the different varieties of French/Bush beans.

[charles]

They are such delicate plants, yes I think again that its to do with heat/sun/moisture balance. At least the new leaves look healthy.
Until today in the UK its been the opposite problem, lack of growth from lack of warmth, whereas as you comment the Czar and borlotti are growing fine.

[Karen]

It is rather odd that none of the leaves of the Czar bean look any where to the French bean leaves. I am relieved though! I am quite sure that the sun intensity here is perhaps a lot more than where you are. This year the French beans were grown in full direct sun…. and I recall that last year I had grown them in a shadier spot and didn’t have such a problem with the leaves.

[Karen]

Took some pics to show how different the Czar runner bean leaves compared to the French bean leaves.

The pic with the Czar plant that is flowering was the lone survivor that I got the seeds from you back in February. I am excited about it!

[Author]

Posts