Maryland Grows

Scary plants earn Halloween points. Some plants are downright scary. Since Halloween is around the corner, I thought it might be fun to discuss a few. 

Raise your hand if you love weeds.  Okay, weeds are my nemesis. Yours too, I bet. If you’ve ever wrangled with mile-a-minute you’ve probably dreamed of this vine engulfing your house, your car, your dog.  Ditto with bindweed, bermudagrass, and other brats. But armed with a little knowledge and persistence, you can get the upper hand.  There’s a good weed ID guide on our website with photos and management tips. 

Much scarier are invasive plants.  These plants are obnoxious spreaders that threaten ecosystems. English ivy, garlic mustard, and others bully out native plants that we – and wildlife – need. Lest you think I’m exaggerating, look at photos of garlic mustard blanketing forest floors or trees smothered in English ivy.  These plants are a serious threat and need to be banished.  Learn more at our invasive plants page.

Have you ever noticed a garden center plant labeled as “vigorous?”  Beware.  That could be nursery-speak for “spreads like wildfire.”  These vigorous plants are often beautiful and can be tamed, but it’s best to go into any relationship informed.  I call them my beautiful monsters, plants I can’t be without but need to manage carefully.

Mint will spread like mad so always, always contain it in a pot.  Brazilian verbena (Verbena bonariensis) will drop seed like crazy.  Deadhead it – or at least some of it – before it goes to seed. Obedient plant (Physostegia virginiana) is anything but obedient.  Dig out its sneaky underground rhizomes where you don’t want it or enjoy it in others’ gardens.  Yes, it’s a native, but it is a serious spreader.  Forewarned is forearmed.

Another scary plant is poison ivy.  I itch at the mention of its name.  The merest brush of a leaf is enough to make me blister. First things first when tackling poison ivy.  Cover any part of you that might come into contact with the plant.  And consider having on hand a product that neutralizes the oils that cause itching. Remove small seedlings by hand.  Sever vines growing up trees.  Treat when you must, following the guidelines in our fact sheet. Ironically, we’re the only species for whom poison ivy is a problem.  It’s a native plant with berries that form late to feed many forms of wildlife. It only irritates our skin and sensibilities.

Less scary are the plants in our gardens with a white latex sap such as milkweed, balloon flower (Platycodon grandifloras), and spurge (Euphorbia species).  The sap can cause minor skin irritations, more of an annoyance than a threat. The same is true with juniper rash, the red dots you get from pruning junipers.  Wear gloves to protect your hands from itchy spots and dots.

I hope I haven’t scared you too much.  Most plants are quite harmless and a delight to both tend and behold.  Into every garden a few itches, weed witches and vexing plants must grow. 

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.  Read more by Annette.