37 Plants That Can Cause Chaos in Your Yard

These plants range from problematic to downright dangerous.

Family Handyman

When you think of unwanted plants, weeds like dandelions, quack grass and others that bully their way into your yard and garden probably come to mind.

But occasionally a seedy character appears that takes over the garden, triggers itching, or causes a whopper of a stomachache (or worse) if eaten.

So how do you know what plants to avoid in your landscape? Start by identifying whats already growing and make sure none of them made this blacklist. Then read on to learn why some seemingly innocent-looking beauties are the biggest backyard troublemakers and how you can fight back!

Too Much of a Good Thing

It’s covered with pretty, purple flower spikes from late summer through fall. A long-lived perennial, it adapts to a wide range of growing conditions. Plus it makes a beautiful cut flower. It’s a gardener’s dream come true, right? Wrong!

It’s purple loosestrife. And as many gardeners throughout the United States and Canada know, this invasive blooming beauty, which has taken over many a backyard garden, has now taken to our natural wetlands.

A vigorous grower, it crowds out native plants, eliminating cover and essential food sources needed by wetland wildlife. Some seed mixes have purple loosestrife in them so, be sure to check the label for this pretty invader.

Purple loosestrife isn’t the only invasive landscape plant causing problems in natural spaces. Norway maples and Amur maples have joined buckthorn and honeysuckle as woodland invaders.

The moral of the story? Do a little research before adding new plants to your landscape. Select plants suited for the growing conditions in your backyard. Then check with your local extension service or area nursery, or online, for a list of invasive species that plague your region.

Keep in mind, however, that it’s possible for a plant to be invasive in one area yet struggle to survive in another. Butterfly bush, tamarisk and ivy are a few plants that are invasive in warmer locales but have a hard time making it in cold, wet and other less-than-ideal growing conditions.

Look, But Don’t Touch

Gas plant, meadow rue, euphorbia and water hyacinths are common landscape plants that can leave some gardeners covered with an itchy, red rash. Though the list of potential irritation-inducing plants is long, not all gardeners will be affected by some or even any of these plants.

The best tactics to avoid the itch are to be careful about what you plant, be diligent about wearing protective garden garb, and learn maintenance strategies that will keep your landscape looking good and your skin rash-free.

Start by taking note of how the offending plant causes the rash, and make changes based on that information. For instance, some gardeners with sensitive skin develop a rash after only a few minutes of handling prickly plants. If this is you, be sure to wear heavy clothing and leather gloves, or convince your thicker-skinned gardening friends to help out.

Infamous plants like poison ivy or even some ornamental euphorbias also contain irritants in their saps that result in a painful and itchy rash. Wear long sleeves if you plan to garden around or weed these irritants out of your landscape. It’s also a good idea to immediately wash the irritating oils off your body and clothing to avoid further exposure and expansion of the rash.

Oddly enough, gas plant, wild parsnip and garlic mustard sap cause a rash only when the irritating oils are exposed to sunlight. That’s why some gardeners weed at dusk or by landscape lighting to eliminate the risk. But if you can work around these irritants only by the light of day, be sure to wear long sleeves and gloves and wash skin immediately.

Deadly Beauties

It may surprise you to learn just how many plants can cause stomachaches, diarrhea or even death when eaten. Gardeners with small children and pets may want to avoid planting the extremely toxic datura and castor bean. The seed in the fleshy red fruit of the yew, the nuts of horse chestnut trees and all parts of the oleander plant are also toxic. And don’t forget the mushrooms Mother Nature sometimes scatters in the yard.

Perhaps the most important thing to do for children is to curb their sense of adventure when it comes to eating items from the landscape.

You should also keep houseplants, seeds and bulbs out of the reach of small children and pets. And store all garden chemicals in their original containers in a secure location.

Lastly, reduce the risk by identifying and labeling all your landscape plants. As a gardener, it’s great to keep a record of what’s planted where. As a parent or pet owner, you never know when this kind of information will be useful in an emergency.

Plants to Avoid!

MAY Cause skin irritation

  • Garlic mustard
  • Gas plant
  • Juniper
  • Meadow rue
  • Pencil cactus (euphorbia)
  • Poison ivy
  • Poison oak
  • Poison sumac
  • Stinging nettle
  • Wild parsnip

Poisonous plants

  • Arborvitae foliage
  • Castor bean
  • Datura (angel’s trumpet)
  • Deadly nightshade
  • Dieffenbachia
  • Flowering tobacco
  • Lily-of-the-valley
  • Nuts of horse chestnut or buckeye trees
  • Oleander
  • Privet
  • Red fruit of yew
  • Virginia creeper berries
  • Water hemlock

Invasive plants

  • Algerian ivy
  • Barberry
  • Buckthorn
  • Butterfly bush
  • Garlic mustard not planted, but needs to be controlled
  • Honeysuckle
  • Japanese knotweed
  • Moneywort
  • Multifora rose
  • Norway maple
  • Purple loosestrife
  • Russian olive
  • Tamarisk
  • Teasel

Plus, 15 trees you should never grow in your yard!