Thanks Patrick.  I guess my only option is to create a new hair object.   I'm guessing this applies to shaders for the hair as well?  What the heck is the point of having hair groups if they all keep the same properties?   sigh  :(

I've used the brush tool a lot and it doesn't look to me like it lengthens the hair.  Yeah, it'll pull it out to it's full length (if you've got a curl to it, or wave, etc.), but not actually make the hair longer than it is.

"You don't know what we can see
Why don't you tell your dreams to me
Fantasy will set you free." - Steppenwolf