I remember falling in love with the dwarf river birch, Betula nigra ‘Little King’, back around 1990 when it was first planted at the JC Raulston Arboretum in Raleigh, NC. This amazing compact selection originated in the late 1970s at King Nursery in Oswego, Illinois, and starting in 1991, was adopted and formally marketed through the Chicagoland Grows plant introduction program.
After 20 years, the original plant in Illinois was only 10′ tall, but the 30 year old specimen at the JC Raulston Arboretum has now reached 30′ tall x 30′ wide So, while it is much slower growing, it’s not exactly a true dwarf. Most estimates conclude that Betula ‘Little King’ will grow about 1/3 to 1/4 the speed and size of the typical species, making it a much better choice around most smaller homes. That said, we love the compact, dense habit and have recently planted this specimen around our home on the JLBG property. Hardiness is Zone 4-9.

full sun for best compact, dense habit?
Yes, full sun for the best habit
I have a ‘Heritage’ river birch. I had no idea it would grow so fast and so large. Had to take it from 3 trunks to 2, now it is threatening to devour my house again. (Insurance agent insists on no branches over the roof). (It is not planted close to the house at all).
Yes, regular sized river birches are quite large…usually 90′ tall x 60′ wide.