baby silver birch trees

 i have 6 baby silver birches in tubes, waiting for the day ;-)

they must have been cuttings, & have buds all the way down to the soil &
some shoots right near the soil.

i am wondering if i should rub off the buds 1/2 way down (or something) &
cut the shoots? or leave it as it is?

thank you for any advice :-)
kylie