"I've used Blaster Pro/Garlon (tryclopyr) successfully though it did take a bit of time to apply.  Mixed a strong solution up with some Roundup added for good luck............ used an old 1 litre bleach bottle with a short length of thin plastic tube…"

"cut the offending root back at the trunk and try and get it out 
sbk will do them but you will need about a foot of growth and leave one to two weeks after treating "

"Chop the roots with an axe or mattock."

"Laurels are pretty hardy and as people have said, will generally recover well from most pest & disease attacks.... Preventative sprays are not the norm (except by growers) but there are a few sprays you can apply as a protective against basal rot,…"

"If you value the customer Just say sorry a misunderstanding , spraying the laurels , roses or anything else for that matter needs to be discussed initially . 
sometimes i have used my intitiative without being asked , sprayed or removed a weed and…"

"What size are the laurels ?  
A garden i have worked in for years has several mature laurels , huge things but planted as a screen and sound barrier to drown out traffic noise  from the main road but prominent from the customers window . 
To be…"

"I would say that spraying anything (except maybe weeds) is not generally considered routine maintenance. Maybe they or their previous gardener used to do it so is normal to them. Perhaps every plant in the garden should be sprayed, preventatively,…"

"I would spray it off, then use a blecavator on the whole area. Then level off using the largest leveling board/lute you can put on your tractors likage, get it as good as possible then seed with a seed mixture designed for football, rugby etc or for…"

"is that richmond north yorkshire "