Forsythia

Forsythia don't forget. 
Same time every year,
as if celebrating your birthday,
they arrive in the yard.
All winter long, one yearns
For this type of surprise 
Forgetting the possibility
Of any such succor.
Yellow petals tip their hats 
in a wave along the branch
-- perennial acknowledgment to 
growth, beauty, and fading away.

Margaret A. Dukes' Questions:

Need some help finalizing the last 2 lines.  Any suggestions?  Not sure the 'acknowledgement to' is correct, should it be 'of'?  Is there a better word for acknowledgment ?  I thought of 'confirming' but I just can't put my finger on what it needs to improve the last two lines.  I would like a word that fits in with the fact that tipping one's hat is an acknowledgement or a mark of respect.