I have used a very convincing argument. I say "I am improving the property value". It will keep us in a very good nursing home vs living in poverty in our old age.
I explain that the house will sell for a much higher price on the market with well maintained land that surrounds the house.
I go into "cost and return of the cost" and if a football game or baseball game, or hockey is on all the better his eyes cross and he says "Carry on with your improvements".
I was and auditor for 20 yrs so I use some of the stuff that doctors do to you when they know if they say the right thing you will let them do whatever they are talking about.