Those Innocent-looking Plants Could Be Bad to the Bone

Yellow toadflax and its cousin, Dalmatian toadflax, are both listed as noxious weeds in Colorado. (Photo courtesy of Harlan E. Herbert, Bugwood.org.)

Years ago, a friend gave me several perky yellow perennials that resembled snapdragons.  I promptly planted them in my garden.

Within days, those flowers popped up everywhere.  I realized something was wrong, so I quickly tore out every one of the charmers, and then researched them.

The perennials turned out to be yellow toadflax (Linaria vulgaris), classified as a noxious weed by the Colorado Department of Agriculture.  If I had allowed those plants to continue multiplying, they might have taken over the neighborhood and beyond, crowding out desirable plants and even poisoning livestock.

Beautiful, but nasty. Myrtle spurge, with its milky sap, can cause blistering on humans, pets and livestock. (Photo courtesy of Kelly Uhing, CO Dept. of Agriculture)

There are other beautiful noxious weeds that homeowners may unintentionally harbor in their gardens.  Common inhabitants include myrtle spurge (Euphorbia myrsinites), oxeye daisy (Chrysanthemum leucanthemum), salt cedar (Tamarix, which I once admired in my sister’s yard) and Russian olive (Eleagnus angustifolia).

If that weren’t enough, you’ll find popular garden plants showing up on what the state agriculture department calls its “watch list” because they have the potential to become noxious weeds.  Suspects are baby’s breath (Gypsophila paniculata), Japanese bloodgrass (Imperata cylindrical), Scotch broom (Cytisus scoparius), pampas grass (Cortideria jubata) and common bugloss (Anchusa officinalis), to name a few.  For those of you with water gardens, be aware that water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes) are on the watch list, as well.

You’ll find many of these plants in garden centers, as well as online, so it’s a good idea to educate yourself about noxious and near-noxious weeds so you can avoid a situation like the one I had with toadflax.  For a list of plants on the noxious weed and watch lists, visit the Colorado Department of Agriculture website.

And before you go tearing out any myrtle spurge and such, be sure to check the noxious weed fact sheets on the Ag’s website so you’ll know better than to tear out those plants with your bare hands instead of treating them systemically or some other way.  Myrtle spurge contains a poisonous, milky sap that causes blistering.