As HouseholdHacker shows us (at the 0:56 mark in the video), sugar contains enzymes that help break down the chlorophyll causing the green stains in your clothes. Just add enough warm water to 1/2 cup of sugar to form a paste.
Cover the stain with the paste, let it sit for about 30 minutes and then wash it as usual. As always, check the garment for any remnants of the stain before you put them in the dryer, where the heat can set the stain permanently. If you need to, repeat the treatment and wash them again.
Awesome Sugar Life Hacks You Should Know [HouseholdHacker]