Azaleas get very twiggy, and become brittle after a few years. As they age and become brittle, the cambium constricts at the twiggy new growth, and eventually causes the tree to weaken. Peter Warren talks about keeping trees “young” by hard-pruning them every few years.
I had let my kurume azalea grow for the last 10 years or so with very little hard-pruning and it started to decline. Look at this progression.
October 2017, after a full growing season, unpruned from the photo above. Look at the anemic growth:
March 2018 before pruning:
And April 2018, after hard-pruning:
It might be difficult to see how hard I pruned it back because the profile is still roughly the same. However, I removed about 1/3 of the ramification, back to secondary branches and leaving a few tertiary branches. The best way to compare is by looking at how much thicker the trunk appears in the photo just above from the one above with a few blooms opening.
A lot was removed, and I was a bit nervous as to how it would respond. Now look at the October 2018 shot:
This tree was last repotted in 2016, and sat on the same bench, same feed, same everything, with the exception of the pruning.
Below is a side-by-side comparison. Spring, no pruning on the left, pruned on the right:
And the after the resulting growing season, not pruned left, pruned right:
I did the heavy pruning just after I removed the fading flowers in April. Likely, I’ll do it again next spring.
The pot? 19″ wide Koyo, signed, stamped, and with the Fuji-en stamp. Dark clay, aqua glaze, with bamboo patterns on the rim and feet.
And here is a fall-color shot…really nice show this year.