The previous owner that we bought our house from had a slew of trees, bushes, shrubs, and other plants growing in the yard. Someone mentioned that we have a Russian Olive tree. Then, I was told that they were illegal now. I think that they are illegal to sell and buy, but what if it is fully grown in the backyard and we never planted it there in the first place?
Certified GKH Gardening Expert
I did see that it is not legal to sell or purchase in Colorado.
It is considered hight invasive so it is not a good plant.
You would not be responsible for an existing mature tree. These laws apply to the sale of seedlings.
Here are a few links for you.