In my school time "das Nadeln" (neuter) was a synonym for "Nadelarbeit" (sewing) and the corresponding verb was "nadeln" = mit der Nadel nähen (see also Grimm's German dictionary). ("Die Nadeln" is the plural for "die Nadel" (female, needle).) http://de.wikipedia.org/wiki/Nadelarbeit
"Nadeln" is also a verb to describe when a fir looses the needels. "Die Tanne/Fichte nadelt" = sie verliert ihre Nadeln.