The message
from "gh" contains these words:

can anyone tell me if it is possible to grow a hebe from the seeds of an
existing plant

It must be; there's a large hebe which self seeds like a weed all over
the place here, and comes up in various shades of 6" long flower from
lavender to white. They seem to take around 3 years to reach flowering
size. If you have a favourite hebe, and there are others nearby, your
seeds may not breed true...but you might also find some lovely new ones
among the seedlings.

Hebes are one of the easiest plants to grow from cuttings, taken around
now, so if you want exact copies of a particular kind that's the
quickest and most reliable way to makes some. Hebes grown from cuttings
will start to flower the following year.

Janet (Isle of Arran)