Combine first 4 ingredients in medium saucepan and bring to boil over high heat.
Reduce heat and simmer several minutes, stirring once or twice, until sugar and salt are dissolved.
Set aside to cool.
Break side branches from center stalk of greens; discard leaves.
Rinse branches and cut into 1 to 1 1/2 inch chunks.
Blanch in boiling water 1 minute.
Rinse under cold water, drain well and let cool.
Divide greens evenly between 2 1 quart glass jars and place 2 slices fresh ginger in each.
Fill jars with cooled vinegar mixture.
Cover and refrigerate 1 week before using.