I spent most of yesterday digging out an old Ceanothus bush that had
suddenly taken a turn for the worst. Half of it died back a month ago
and was pruned and burnt. The cuts showed a red orange ring in the
diseased wood.

The rest of it succumbed in a matter of a few days from healthy
looking green bushy plant to distinctly dead. It seems they are
succeptible to verticillium wilts. What other shrubby plants should I
not plant back in the large border ap where this came from, and how
deep should I dig out for the old roots?

There is a mushroomy smell and white hyphae in another part of the
same border, but AFAICT a clear space between that and the affected
bush. I don't really know much about these fungal diseases of plants.

Thanks for any advice.

Regards,
Martin Brown