[vineweevil1]

I have abut 8 tom plants in all, some in g'house and some on patio. 

The one variety LIDL, the leaves have gone yellow on the outdoor one's and the indoor one is heading the same way.  I thought it might be magnesium deficiency as I have read this could be brought on by irregular watering (guilty), so I have sprayed with diluted epsom salts, no change yet - any ideas???

Some of my cucumber (g'house) leaves are going light green between the veins (only slightly) not sure if these are going the same way???

[JWK]

Sounds like they are lacking in something or the roots haven't developed fully. If they have flowers and the first fruit has set its time to start feeding them. Are they in pots? If so they might have run out of nutrients, pot them on or get them into growbags or into the border.

[mumofstig]

The yellow leaves don't usually turn green again after spraying, it just stops the rest from going yellowy.
Magnesium deficiency is not due to watering problems, it means there is not enough magnesium in your soil/compost....some varieties seem to suffer more than others don't know why!
But irregular watering sure won't do them any good..it can cause blossom end rot, a black rot on the bottom of the fruits. (and it can be fatal..poor toms RIP )
You could try feeding toms and cue with half strength tom feed until they set fruit.

[vineweevil1]

Thanks for the responses.  The worst one is still in a 6" pot (saving until my mom gets back from hols next week), then the next worst I have put into the border and the final one in a double size growbag with tomorite compost.    No fruit set yet, just flowers, maybe I will try a half feed.

Cuc's going same way and it does have fruit on it, have been feeding once a week with tomorite, should I do this more often?

[mumofstig]

No the once a week should be fine... i'd just carry on like this for the cuc.....hope it settles down...but cucs can be awkward bu@@ers!