Dig This! Uninvited Guests: Some Welcome, Some Not

DC’s warm climate and loads of green space—both private and public—make it a plant’s paradise for growing and spreading. You, too, may have had a plant just “show up” in your yard or flowerbox (oh how that invasive bamboo spreads!). It can be hard to know which uninvited guests to let stay and how to rip out. Below are two plants—one to welcome to your yard and one to rip out at first sight!

Be Gone!
I always like to end with good news so let’s get the “tear it out” plant done first. Garlic mustard (Alliaria petiolata) is pretty when fully grown but don’t be fooled by those toothed leaves and tiny white flowers—this invader will crowd out other plants that critters like the rare West Virginia white butterfly (Pieris virginiiensis) and loads of other beneficial insects need. Luckily garlic mustard is easy to pull so, don’t hesitate when you see a newcomer pop up. Once the garlic mustards are mature they can send thousands of seeds several meters away. You can find great photos online that help ensure you indeed have garlic mustard. In 2017, The New York Times ran an article titled “Garlic Mustard: Evil, Invasive, Delicious.” So you can eat what you pull!

Let It Thrive!
On the “good” side is Pennsylvania smartweed (Polygonum pensylvanicum). I see this native beauty all over Glover Park and love to see it filling in space in front of my house. PA Smartweed provides food for various wildlife and is hailed by some as great-tasting and even medicinal, although I can’t vouch for any claim other than the wildlife benefit. It also doesn’t take over a location, so I let it grow anywhere it chooses and enjoy watching the birds eat the tiny fruit and seeds from it. I confess I’ve been heartbroken to see this beneficial pretty little plant torn out repeatedly on my own street and delight when it’s mature to its full height of about three feet. With summer coming, you should have many opportunities to decide for yourself to pull or welcome these two plants. My next column (in September) will be on my favorite DC native: Pokeweed! If you have plants you love (or despise), I’d love to hear about them.