I have a deep backyard with a sort of wild ravine behind it. The city owns it, but judging from the state of repair, it's of no worth to them and is of much worth to me. It has become infested with garlic mustard, so we've taken to pulling it as soon as it emerges. Since garlic mustard is a biennial, you gotta stay on it for a while, because just a few seeds can make a big mess, and the plants take two years to mature and bear seed. I have heard it takes five to seven years to totally eradicate. At least it makes a decent pesto.
The nasty part about garlic mustard is that it emerges first, blocking light that is essential for the early Spring ephemerals, so they crowd out the native cool stuff.
After pulling a trash bag full of mustard, I found a few little treasures hiding under the canopy. They're little Jacks in the Pulpit (Arisaema triphyllum), a native Wisconsin species that managed to keep a toe-hold while we clear out the nasties. They'll spread now, and we'll keep at it until the JITPs replace all the GM.
There was also a few small Solomon's Seal, some phlox, and a lot of invasive trees like silver maples and buckthorn. Truth be told, the little Jacks have inspired me to clear out the invasives and help re-establish a nice native plant shade garden. It's a long-term project, but I'm not going anywhere anytime soon.
2 days ago