Gemma Zucchini This page first published: Mar 31, 2005 · Modified: May 9, 2018 · by CooksInfo. Copyright © 2020Gemma Zucchini has very dark green skin, so dark that it almost looks black. History Notes Gemma Zucchini was developed by Asgrow Seeds. During development, it was referred to as XPH 1641. Released 1993.