Can Tomatoes go in the Potato bed?

Trouble is they are also both prone to the same blight disease so if one cops it the other is likely to as well. Planting them as far apart as possible is about all you can do in that respect (without resorting to spraying) but as ever it's a lottery every year.

(You could therefore argue that you might just as well plant them together and hope you get lucky, although personally I always like to "play the percentages" if at all possible!)

I would fit in whatever you don't have room for that likes the same growing medium. How about sweetcorn - they will grow higher than the pots and not be shaded by them  - and they like lots of manure too.

I agree with gillie - same family goes in same bed!

If you're gonna get blight on your plot, then having the toms 1 or 2 beds away from the spuds will make beggar all difference I'm afraid

plus you have no control over where the next allotment grower puts his spuds or toms, so you might just as well keep them all together

Regarding blight though:
Do tomatoes and spuds suffer the exact same version of blight? I ask because last year my toms got blight and I didn't notice it on my spuds and they were planted within 3m of each other.

Sort of! The fungus-like organism is called Phytophthora infestans and the same one affects both spuds and toms. There are different strains of the organism and different varieties of spuds and tomatoes have varying degrees of susceptibility to them. The local microclimate can also mean that there are slight variations in the amount of leaf-wetting and drying which can affect whether the spores actually germinate or not.

As I said, a bit of a lottery, but worth entering far more often than not! 

Perhaps I've been lucky or more attentive to tomato plants than the potatoes, but I've noticed blight hits the tomatoes earlier and seem to be more devastating than potatoes.  Touch wood, I've always managed to rescue the potatoes in time even after a bad case - at least you can cut the haulms back and leave the crop in the soil (albeit smaller harvest than if you'd managed a full season without problems) whereas once tomatoes are diagnosed, it's much more difficult to do anything about them.  I understand the spore in the air scenario and neighbours who may not attend to their crops as well, but personally I'd keep mine apart.