I moved you over to the spiritual section, Watcher.
Although I do have ashes on my property, they were put there to rest, not as a use for making the property holy. Blessing a property is what I had done before the ashes were added there. I have also used holy medals to ward the property, specifically St. Benedict medals.
Depending on your spiritual or religious preferences, blessing a property may take different forms, but it's normally using the intention of having the One/God/Creator involved in the blessing of it.