Sweet Pea and SWR

Sweet-pea-flower

http://en.wikipedia.org/wiki/Sweet_pea

Spring has come, and I renewed a green curtain for my sweet pea, a climbing plant, using the antenna element and a net as support.

Last year, the system worked fine both for a curtain and an antenna, but now I found that the SWR is around 5 on almost all bands. What’s wrong?