I have seen them hanging and looking very decorative. The glass and colors adds to the artzy look. Spiked eliminates the need for string or wire tying...and since outdoors, those ties can sometimes rot. 99 percent of what I see are spiked or on welded rebar. The bottleneck slides over something stiff. I just thought you might like to have an historical perspective on how the southern bottle tree was used on the plantations and such. Those bottles are intended to howl..
