I have the same question regarding white birch vs river birch. I'm hoping that my (newly planted) river birch are just late to leaf out; otherwise they are toast I guess!

spedigrees My question was inspired by something different. The volunteer maples around me seem to come in two distinct groups; one that is totally leafed out, the other that has tiny leaves and is just starting to leaf out. Trying to find out if that gives any clues as to species. Want to keep Sugar maples and pull up volunteer Norway Maples.

Your birch...were they planted bare root? How recently? I know bare root trees of some species sometimes sleep really late in the summer.

Did you do the scratch test?

edlincoln, our volunteers tend to be red or swamp maples. This link shows examples of maple leaves, scroll down to see the Norway maple leaf. Maple leaf ID

Ed, right now is the toughest time to tell the difference, as they are leafing out IMO. The best way I know of to distinguish between Norway and Sugar maples is to wait until the leaves are fully out. The Norways have milky sap when the leaf is torn or at the base of the leaf petiole where it breaks off. (I don't know if it works as they are leafing out since I've not tried it then.) In the winter, the buds look different, with the sugar maple having more pointed, darker, smaller buds, with smaller side buds at the end when compared to the central terminal bud.

I would guess that timing probably isn't a good predictor, though I am not sure since I don't know of anywhere nearby that has them growing side-by-side. However, the patterns of genetics and sun and shade as well as soil moisture seem to make a lot of difference here between various maples of the same species. I often see red maples with very different timing for leaf out and drop even when they grow in the same spot, so I think it may be that way for other maples as well.

Defrost, sugar and Norway maples' leaves look quite similar (along with black maple), which is why Ed is having difficulty. The easiest way to tell oak from maple is to look at branching patterns since oak is alternate and maple is opposite.

LOL NHBabs, the trees that are lagging behind that I can see from my window are at the corner of the woods with so many trees around them, I can't quite tell which branches go to which trees. There is also a wild apple tree that is tall and skinny due to the number of trees around it but apparently it can get enough sun.