Needing a Bit of a "Nudge"

I don't know if I'm the only one experiencing this, but I have recently had several students who are having problems practicing!  By that I mean...they don't want to!  I attribute a lot of it to the time of year - It's been a VERY long winter and they are ready for spring, as am I! - but also know that it's making a frustrating time for parents and their home life.  Soooo..., at this weeks group lesson I am working on an additional incentive program to try and add a bit more fun and a bit of "motivation" to practice. 

I am considering starting a grid type chart for each student.  For each week or for each day they practice well and don't give their parents a hard time about it (obviously parents will have to sign off on this!), they earn a sticker in the chart.  The program would last until June (about 8-9 weeks) and those who managed to get a predetermined amount of stars would earn a special "Practice trophy" at the June recital.  I also thought about adding a bit of competition...to see who can put in the most practice days between now and June. 

Before I finalize it, I wanted to ask all of you if you are having the same problem and if you have any suggestions for ways to add a bit of "enthusiasm" at this time of year. Would this idea appeal to your student?  Would you do it another way?   I would appreciate any ideas you have or things you have used that worked well.