How to revive a rather tired Azalea

Any advice on how I can revive my Azalea?

See photos, it does give some some nice red flowers but I am sure it can do better. It has been neglected by me for a few years, I never prune it. It just... sits there. What can I do to revive it?



My garden book says gentle pruning is required, trim back but avoid cutting into old wood, However it does not say "when" to do it.

(edit: the photos are from a month or so back, not right now)

 

Looking at it, I would say it's in need of some new soil . Not the right time to dig it up now of course. Better when dormant - late Autumn/Winter .But now, make sure it has water and a solution ofhttp://www.amazon.co.uk/Miracle-Gro-Azalea-Camellia-Rhododendron-Liquid/dp/B0041WCM22 would help until the end of August - no later.
In late Autumn/Winter, gently dig around the bush to the tips of the branch growth and to a depth of the spade. Prise it up with care and inspect the root ball. If OK, then remove soil in the hole by another 12 inches and replace with Azalea/Ericacious compost and and handful of Blood,fish and bone . Replace your shrub to the same depth as it was and water and feed it next Spring .
Others may have different advice,
Jenny namaste

 

The colour of the azalea looks similar to vuyts scarlet ... Is only a guess tho
It's more than likely lack of nutrients in the soil
Totally agree with Jenny but would suggest a product called sequestrene .. Which is like a lucozade for us humans... A pick me up tonic.............
Plenty of drink ......

 

Looks like its had a hard life, is it in full sun all day?
They like a bit of shade and moist growing conditions.
You could dig out the grass around the base of the plant and maybe give it its own growing space.

There could be an iron deficiency as Doug suggests, so a watering with sequestrene would not hurt,(it needs acid soil to do well), but mainly I think it gets too dry.

 

I use Vitax Seaweed plus Sequestered Iron - Maxicrop do one as well.

It should be pruned just after flowering. Have a look here for more advice.

I would also agree with moving it to somewhere with part shade.

 

Namaste Jenny! Thanks very much for your reply and too all the others. I have not dead-headed them at all this season (or anytime before now) so I am not sure what to do now. I think I should try and "neaten" it up (remove thin woody stems, deadhead as link above). I am only now starting to water it.