What to do about lily-of-the-valley?

I am saddened by my discovery that lily-of-the-valley (Convallaria majalis) is non-native and somewhat invasive. The scent and flowers are beautiful, and it fills shady spaces perfectly. But I guess I can't in good conscience use any more of it. Fortunately at present it is only in two fairly contained parts of the yard where the rhizomes have nowhere to go (except into the lawn from one area, and under a fence into a neighbor's garden from the other). I can't bring myself to consider ripping it out, not with so many other nastier species to worry about. I'm pretty sure birds don't spread the seeds given that they are toxic, and aren't produced in large quantities.

6/3/14

My hope was that mine would turn out to be the American sub-species rather than the European one, in
which case its aggressive nature would be an advantage. Unfortunately I think not. I found the following on Lady Bird Johnson Wildflower Center/Ask Mr. Smarty Plants site [http://www.wildflower.org/expert/show.php?id=8139]

'In the paper listed above (Ghandhi et al.), they propose the following names Convallaria majalis subsp. majalis (European Lily of the Valley) and Convallaria majalis subsp. majuscula (American Lily of the Valley).  And, although the paper notes that there is an overlap in features (length of bracts and pedicels, leaf blade size and venation, number of flowers per raceme, etc.) used to distinguish the American and European species, it offers these differences:

"1. Plants forming dense colonies; leaves green until frost, veins faint; raceme (excluding scape) about half the length of the leaves; bracts 4-10 mm long, shorter than the pedicels; seeds almost globose...subsp. majalis [European]

2. Plants scattered or forming small groups; leaves yellowing in late summer, veins strong; raceme (excluding scape) much shorter than the leaves; bracts 8-20 mm long, usually as long or longer than pedicels; seeds oblate or lenticular...subsp. majuscula [American]".'

Mine forms dense colonies and the raceme description fits, as does (if I understand the terminology) the bract/pedicel description. With no comparison I can't say if the veins are faint or not, and I don't see any seeds yet. So odds are I have the European version; if the leaves stay green till frost it will be pretty conclusive.

6/3/14

6/3/14