Dud radishes

My radishes produce plenty of leaf (treat like spinach, delicious), but very few 'radishes'.  My thoughts:

Too little organic matter; too little water; planted too close together.

Any other ideas?

All of the above!  Radishes like cooler weather, loose soil and regular moisture.

>fleabeetle

Is that what leaves the little holes in all the leaves in my garden?  Quite well then, thank you.  That's what keeps the Blue tits and robins happy.  I also have a pair of Thrushes, wrens, multitudinous black birds, too many magpies, even a jay, the odd sparrow, wood pigeons a-plenty (ask my cabbages).  And all this less than a mile from Tower Bridge!