(Thinking I must be missing a joke here but just in case I'm not...)

Highbush blueberries might be head-high, but you won't find highbush berries in canoe country.

Wild blueberry plants rarely grow taller than mid-calf.

Also:

Blueberries can come in earlier than the 4th, too.  Spydor is right that most years few will show up before then but this year the crop was early.  We had no trouble picking berries enough to put in a batch of pancakes and in a batch of oatmeal.  Had I seriously thought we'd find so many this early, I'd have brought some bannock mix or muffin mix.