The residence was not affected and does not figure into the equation. You lost trees.
Decrease in Fair Market Value Fair market value (FMV) is the price for which you could sell your property (trees) to a willing buyer when neither of you has to sell or buy and both of you know all the relevant facts. The decrease in FMV used to figure the amount of a casualty or theft loss is the difference between the property’s FMV immediately before and immediately after the casualty or theft.
In your case, after the FMV of the trees after the event was zero. You need to estimate what the FMV would have been before. The replacement price of the trees is a good approximation.
