Not sure. My walking onions multiply under ground as well as forming bulbils at the end of the thick stalk. I see both right now. a few green clusters of leaves emerging from a few onions and the stalks with only a light green bud present. In a few weeks the buds open to form the bulbils, and the ones in soil start to get smaller and seem to seperate again. MIne are only about 2 feet tall most of the time.

Just out to measure the Catawissas. There are two topping at 43" for the moment. With few exceptions, the bulbil formation is right at 30" throughout the patch. Two separate Egyptian plots vary from 24" to 30" for bulbil formation. Their stalks are indeed impressive for thickness! Several have decided to grow in an arch rather than straight up. Neither varieties have begun to split bulbs yet.

Martin

Geezer,
When mature, I believe there will be 2 to 4 bulbs underground. If My memory isn't as bad as I think it is, if you snap off the bubils, they will reform or it will send up another bubil stalk. It has become apparent, reading all the postings, that different zones and conditions give different results. ie, some things that are stated as absolute, are often somewhat different here.