Question
Hi Jim,

We live in the East Bay of the San Francisco area and have a sloping hillside behind our house where directly behind our house (20 feet away) the hillside drops off at about a very steep angle.  At the top edge of the drop off angle we have a very large pine tree +/- 60 feet tall.  Lately we've noticed the dry soil sliding off around the roots on the half of the tree that's exposed to the steep slope.  Are pine tree roots deep and strong enough that the tree will not fall in this condition or do you think we should have it removed to be on the safe side?

Thanks,

Brad

Answer
If the soil is not stabilized the tree over time will fall when the soil is gone from more than 1/2 of the root system. When this will happen depends on the weather conditions over time. IF the tree when it falls will damage something below I would go ahead and remove it. BUT if the tree when it falls will hit nothing just let it be and enjoy until it does fall.