Why did I grow that plant?

Knowledgeable gardeners call them "garden thugs" -- those aggressive plants that look or sound so enticing until you get them in your yard. Then they show their true colors and try to take over everything in their path.

Then the gardener discovers another aspect of these plant bullies -- often, getting rid of them takes a great deal of work. They don't go quietly. You try to pull them up, but they sprout new roots and continue growing even more vigorously. Or they pop up -- over and over -- far from where you originally planted them.

Anyone who's been gardening for a while has encountered at least one of these tyrannical plants. But for the novice, it's not easy to know beforehand. What's invasive in one area or one garden isn't in another, as "Snapdragon" mentions of her leopard lily.

However, here's a clue. Valerie Adolph of Foxglove Corners blog advises: When you are shopping for plants, beware of tags that say “Spreads vigorously." It’s a euphemism for “Plans to rule the world.”

Her choices to top of the list of plant thugs: English ivy and lamium, a ground cover with pretty silvery leaves.

For Stuart Robinson, the big pest is evening primrose.

Stephan Gabos reminds us that herbs can be bullies, too. He mentions mint and lemon balm.

Alstromeria -- found in so many florist arrangements -- gets Jessamyn's vote for chief plant thug in her garden.

Even roses can have the tendency to be take-over artists. Dee of Red Dirt Ramblings in Oklahoma says: "New Dawn’ although beautiful is a garden thug here. She has consumed most of my back fence, and she is THORNY!"

My advice: Watch out for plants with no names and those that a neighbor or "friend" is anxious to share (often because they have way too much and want to get rid of it.) Mint and ivy often top the list of give-aways. (Remember the adage, you get what you pay for.)

I would add wisteria and creeping bamboo to the problematic list in all parts of the country. My own big mistake was planting Houttuynia cordata 'Chameleon,' a lovely little plant with multicolored leaves. Its take-over tendencies make it a perfect candidate for head dictator in the plant world.

I suspect that whoever lives in the house where I planted it is still, 15 years after I left, finding it invading the lawn.

What garden thugs have been your worst problems?