I planted each whole plant without pulling it apart in mid- to late spring. It had no leaves--or they were trimmed at the time. It disappeared during the summer, but I left it over the winter, thinking it would multiply. I started seeing shoots in winter. But what I pulled this spring were just a few cloves from each cluster, not nearly as many as were in each original cluster.
I added "/leek" when I learned from Ken they're actually leeks.
