Barry Epstein asked:
Can a tree planted by man be forbidden as an idol? Is it considered attached like a house, and therefore not forbidden (like the mountains)?
Barry Epstein, Dallas, USA
The Kollel replies:
A tree is subject to a Machlokes on 45b. It depends on whether the reason why a mountain cannot become forbidden as an idol is because it is attached to the ground, or because man had no input into its creation.
By the way, a house, according to Rav, is not considered attached (47b) and becomes forbidden.
D. Zupnik
(See also Daf-Insights to Avodah Zarah 47 and 48.)