The message om
from "Old stoat" contains these words:

I'd like to plant a group of three birches, probably jacquemontii,
together, as I gather that they restrict each other's growth. Does
anyone know if they actually do that, and if so, by how much- a bit, a
lot or hardly at all?

Thanks

I wasn't aware that they are supposed to restrict each others' growth
except insofar as any close planting is perhaps restrictive sao I was
interested in the theory. I have three Betula jacqemontii planted close.
They have grown to perhaps fifteen feet in about seven years.

Janet G