Hydrangea Chlorosis

I have an old Hydrangea (guessing 10 years).  It has stopped blooming for a good number of seasons now.  And since I'm such pro worms, I never did apply chemical fertilizer.

Here's before (May) and after (July) shot.  What has happened is that my plant has developed chlorosis or discoloration of the leaves due to some nutrient deficiency (nitrogen, magnesium or iron).

I've read that soil alkalnity impacts the ability of plants to take in those nutrients.  Given all the egg shells and banana peels I've dumped in the pot over the years to try and get it to bloom, I'm guessing the soil's pretty alkaline by now.

To remedy the discoloration, I've added some vinegar to the water I use and I've also added a good amount of coffee grounds.  Finally, my rabbits also contributed a substantial amount of old hay and hundreds of poop.

Apart from the addition of organic content, I've also pruned the stems very aggressively.  Interestingly, I just plugged the cuttings in soil somewhere in the backyard.  While most died, a couple actually rooted.  I've moved one of those cuttings to a hydroponic set-up, but that's a story for another day.

I honestly thought greening up the leaves will be faster but it took all of two months before the picture can tell the difference.   Next stop is to try and make it bloom (years in the making and going).

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