The Mirriam Webster Dictionary defines obnoxious:

Latin obnoxius, from ob in the way of, exposed to + noxa harm ; 1. exposed to something unpleasant or harmful ; 2: deserving of censure3: odiously or disgustingly objectionable : highly offensive .

ob·nox·ious·ly adverb — ob·nox·ious·ness noun

The term Noxious, as in Noxious Weeds/Plants, is defined as:

1 a: physically harmful or destructive to living beings b: constituting a harmful influence on mind or behavior ; especially : morally corrupting 2: disagreeable , obnoxious synonyms see pernicious — nox·ious·ly adverb — nox·ious·ness.

See where I am going with this?

There are some plants you should not plant. I don’t CARE how much you love them and how nice they look in your garden. To plant them is to disregard your responsibility as a steward of the planet. And in case you haven’t heard, the planet is Hot, Flat and Crowded.

I know of licensed landscape architects who should be spanked for their use of plants that appear on the Idaho Department of Ag’s Noxious Weed Watch list, namely purple loosestrife and orange hawkweed. These people ought to know and DO better. I have actually had them tell me, “the plant is so perfect for that spot.” SHAME on them, and after reading this, if you plant these plants: SHAME on you. I hope they are willing to bear the title, Destroyer of the Good Earth.

The plants I am about to list have the potential to become the next cheat grass or yellowstar thistle of the American west. After cheatgrass (bromus tectorum, an introduced Eurasian weed) fueled range fires burned almost a million acres in Idaho last year, the governors of Idaho, Nevada, Utah and Wyoming finally caught on and declared war on cheatgrass.We won’t even attempt to tackle the issue of how bromus tectorum became so prevalent in this part of the country. I guess you could say cheatgrass has been settin’ the world on fire. And not in a good way.

Stipa tenuissima (mexican feather grass) has taken the garden design world by storm. Plant it once, and you will never be rid of it. Yes, I know it gives that sought-after wispy glow that moves ever so gently in the evening light. Don’t plant it. I planted one small piece of it 7 years ago, next to my driveway. I dig it out every single time I see it coming up, I hit it with Round-up, I hit it with anything and everything in my arsenal of plant killing chemicals. I am not winning.

Second on the list of bad ass plants to be avoided at all costs: Carex buchananii, commonly known as leatherleaf sedge.Call me out of touch, but I have yet to understand the appeal of growing a plant that appears to have died in place.

bad ass buchananii

Yet this plant keeps rearing its ugly head in designs around the country, in container gardens, in magazines, and in places where people ought to know better. Plant it once, and you will have it forever. I have seen it move from a perennial border, to the parking strip (hell strip between the sidewalk and the street), then across the street and down the sidewalk to a neighbor’s lawn. If that isn’t invasive, I don’t know invasive.

Bad Bad Carex buchananii. BAD.

This next call hasn’t won me any friends of late but I can take the heat. Stop planting , Perovskia atriplicifolia commonly known as Russian sage. Please. Stop it now.

Step away from the spade. I know it has a certain ethereal blue quality. I know it blooms in the hottest part of the summer and brings a sense of renewal to otherwise tired looking heat stricken gardens. JUST SAY NO to Russian Sage. You know who you are. There are reports of it getting away from gardens and into the front range/foothills areas of Wyoming. I can see how that could happen. I live about 20 feet from the Boise Front, just a couple hundred thousand acres of wild land, cheatgrass infested wildland, former rangeland. I water my urban space, providing a comfy place for perovskia to thrive and then, poof, it throws seeds into the driveway, the quail or the wind pick up the seeds, and off they go across the street to the nearest 100,000 acres. Out came the sage when I heard the news from Wyoming. Do me a favor, rip yours out, too. Be the good gardening citizen.

For a reality check: check this out and adhere to it: , the Idaho Department of Agriculture’s Noxious Weed list is here : www.idahoag.us/Categories/PlantsInsects/NoxiousWeeds/watchlist.php