Well as I write we are in the middle of what the Europeans call Summer and what we here in Albion refer to as a heatwave! However, it is many weeks since we here in Sussex have had even a drop of rain and to be honest it is getting a tad worrying! To save water I am saving washing up water to pour on my ornamental plants, and this is fine as I use eco-friendly washing up liquid, and save the pure water for my edible crops. Mulching after watering is a good idea too, to stop evaporation. Spare a thought for our wildlife who have no taps to get water from. If you can put fresh water daily in birdbaths, the birds will be grateful as they need to be able to bathe to maintain their feathers, as well as drink the water, and putting bowls of water on the ground could be the difference between life and death for badgers, deer, foxes and of course hedgehogs.
If you grow comfrey, it makes a fantastic tomatoe feed, or indeed a feed for all vegetables. Cut it down and chop it up a bit leaving in a bucket of water for a few weeks until it goes black and smelly. Then dilute and feed your veggies!