Northoscordum sellowianum is a rampant (to the point of almost weedy) grower down here. It seems to prefer acidic conditions (add a little Holly-tone) and definitely prefers some summer moisture. It blooms nonstop from January-February. A good winter blooming species here. All varieties of Ipheions are rampant growers almost to the point of being weedy here (but appreciated for their early blooms). But they will take a lot drier summer conditions than N sellowianum. They are all at their peak about now. Debbie Houston, Texas (zone 9a); where H glausecens is about to bloom