Rhododendrons Blooming - June 2021

We have a pair of Rhododendrons planted on either side of our rear stoop that we put in the ground in 2018 as part of our plan.  I have never pruned them, but have protected them a little bit in Winter using Wilt-pruf a couple of times.  These are evergreen shrubs and they put on a nice flower show most years. But, this year these shrubs looked a little sad earlier this Spring.  They were yellow, drooping and leggy.  I bought some Epsoma Holly Tone this year to feed my hydrangeas and these Rhdodendrons and it seems like they've responded a bit.  I'm pretty sure they have an iron deficiency - as outlined here by Ortho.  Purdue University Extension office has a post up about this yellowing - called chlorosis.  

I have started to feed these with a little bit of coffee grounds, but I think that I'm going to need some more drastic action to correct the iron.

But, back to this season:  these two shrubs are flowering right now with light purple flowers.  Here, below are the pair of them.  First, the one to the north of the stoop.  Then, the one to the right:

I've begun to look at the best time to prune these things - and it seems like the first thing I can do is to remove the spent flowers and what they call flower 'trusses' that come out of the buds.  You can see in the photos that these are both yellow(ish) and not super compact.  Pruning + feeding is in store in the coming weeks.