Garden greens are natures' own vitamin and mineral storehouse. Fortunately, you can always have a few varieties ready to harvest. Most greens will withstand winter like conditions provided they are not extreme or much lower than 10° without some type of protection. Even snow works as a winter mulch for most greens. Sow in early spring and then again in August for a fall and winter crop. Approximately 15,000 to 20,000 seeds per ounce or 530 to 700 seeds per gram.