All the brassicas now have bottles dug in next to them, so we can water straight down to their roots; which means we will use less water and not help the surface weeds along by giving them a drink. The tomatoes will be next to be 'bottled up'. Looking round the allotment site I've seen a few other allotments using the same method.
The sunflower with the ashes around it seems to be flourishing - However, it's probably a little too soon to declare ashes as the answer to the slug problem!!