I've had this smokebush for 5 years now. I've been training it as a tree and so letting it grow tall to about 10 feet. I started noticing this year that it's been very delayed in leafing out. While I thought it died at first, it just started to produce leaves. In the meantime RP smokebushes in my neighborhood had produced leaves weeks ago - even the one that looks like a tree (that I've been trying to ape). What have I been doing wrong? or should I suspect that my plant is diseased? or is it climate change?

Should I just rehabilitate it and cut it down to a stump? If so when should I tackle the job.

Im in Canadian zone 5b (borderline to zone 4). the shrub is located in a southfacing yard. Weather has been unpredictable swinging from really warm to cold.

Ianna