Blossom end rot on tomatoes

mary359

Why are my tomatoes getting blossom  end rot. I grow in grow bags.  Mary

BobFlannigon

It's usually inconsistent or insufficient watering but can also be caused by nutrient deficiency.

mary359

Thank you I keep watering grow bags two or three time a day. Doesn't seem to be enough.

BobFlannigon

It might be nutrient deficiency, do you feed them fairly regularly? 

This page may prove useful...

https://www.rhs.org.uk/advice/profile?pid=395

Dovefromabove

Overwatering can cause BER as much as underwatering can.  The knack is to be consistent ... I find that by that letting the top inch of the compost dry out and then giving the plants a really good soak (usually just once or twice a week, depending on the weather) gives good results.  

We've fed three times with tomato fertiliser and once with seaweed fertiliser ... starting when the first truss set and then at approximately 10 day intervals.

We've only had one single fruit with BER out of twenty heavily cropping tomato plants, and that's been my experience ever since we adopted this method.

I also find large bucket-sized pots give much better results than growbags. 

Last edited: 15 August 2017 11:31:17

mary359

Thank you. I think I will try pots next year.

Dovefromabove

I think you'll find it easier  - let us know how you get on 

REMF33

I am tagging onto this as I am getting it quite a bit of BER. All my tomatoes are on Quadgrows (tanks of water with wicks going up through the pots, which should mean that they have a constant supply of water) which I have been using for about ten years, now - the only time I have had BER before with plants on this system is when I've been on holiday and the cat sitters haven't filled the tanks or watered them enough. (I did pay them, but it was probably a bit much!) No cat sitters this year, as no holiday. But, I haven't been feeding them much/enough. I know. Foolish and negligent. Would that cause the BER? I understand it's caused by calcium deficiency but is there calcium in tomato food? Or is that now how it works? I hope a concerted frequent feeding program will solve the problem.

The only other thing I can think of is that I have sometimes watered from above, which you are not supposed to do, so perhaps the 'feeder mats' are not wicking up the water properly. (hopefully it's not because I just bought a sheet of capillary matting and made my own wicks for some of htem because Greenhouse Sensation were taking 3 weeks to deliver stuff...) Since correcting the problem is more important than science, here, I am going to let the tanks run dry and the compost dry out a bit, rather than topping up the tanks all the time, and won't be watering from above again.

REMF33

Oh I did get a product recall from Greenhouse Sensation saying that the batch of plant food I ordered was missing an ingredient. I have contacted them (no reply. I guess their one customer services person is on holiday again...) but I am rather inclined to think that this is somehow my fault/mistake!

Allotment Boy

The greenhouse sensation plant food that goes with the quadgrow system is in 2 parrts, to be mixed just before use. Part A should contain added calcium.  Perhaps that was the missing ingredient.  
I am using the same system and have had some BER  this Year but only on the first few fruits. The later ones are OK.

REMF33

It is the A part that is faulty but I still haven't heard from them so don't know if it's calcium that's missing. Would be interesting to know (plus I would like replacements for the two I've not opened!) I am going to get some appropriate fertilizer with calcium and try that. I doubt it would do any harm. As I said, I have not been feeding them enough anyway. Most of the tomatoes seem fine to eat if you cut off the manky bit, at least, so not a complete waste but still galling.