Just a quick update. I am repeatedly being asked how to rescue plants that are already scorched, swooning or have fried in the the heat. So how or indeed, can you rescue a plant that already has been torched? Is it dead or not?
Yes and No.
For perennials; If there is still a fair amount of healthy green growth, cut the plant back to the the low basal growth give it a feed and just water it regularly and you should be able to nurse it back to reasonable health. If the plant is brown from top to toe but when you tug it, it still clings solidly to the soil the chances are the roots are still hanging in there. Cut back all growth completely and ruthlessly, water regularly and it may well put out new growth between now and October.
Shrubs; Much the same as above. Cut out all browned growth (where practicable) and reduce the overall height of the shrub by say a third, so that the plant doesn't have to work so hard keeping all that foliage going. Put a thick ring of organic matter around the base of the plant. Water it well three times a week- a few gallons please not just a tiddly splash from the watering can! Crispy-looking trees too can benefit from organic matter and perhaps a leaking hose at night to sustain them.
Let me know how you get on ...