Holy Spurge…where did that come from?

Several people have asked me why Leafy Spurge (Euphorbia esula) has made such a big comeback from their efforts to manage the noxious weed. Their concern is justified looking at the amount of spurge that is in the Milk River drainage, from the Phillips County line to Havre.

While this is not a strictly “scientific” explanation, this increase could be simply that leafy spurge has a deep taproot (about 20 feet). In dry years, like 2018 and like this spring, deep-rooted plants do better than shallow-rooted plants. Spurge probably made a gain last year without being noticed. This year it...