Those look so painful. Why don't you think about Crosnes? Also known as Japanese artichoke or "Stachys affinis". It is an understory root plant, it is in the mint family so spreads REALLY easy. LOL. It is good in stir fry and salads. And as an added plus, it won't scar/sting you.
What's a year in metric? Do you know this metric stuff tiny ad?