Yes, you read that title absolutely right! There are certain perennials out there that could possibly be ruining your garden instead of improving it!
In this article, I’m going to tell you why that is and what alternative perennials you can plant to bring the situation under control. Let’s dive right into it!
Why Some Perennials Cause More Harm Than Good?
The first reason why some perennials can cause more harm than good is that they’re invasive and can take over large parts of your garden in a short time. They limit the growth ability of other plants and can keep them from having as big of a visual impact in the garden.
Certain perennials attract tons of pests and insects to the garden that damage other plants surrounding them. This means that, while your perennials may be adding beauty to the landscape, they’re also ruining it.
Many perennials out there also don’t go very well with other plants and tend to create unnecessary competition in the soil that benefits neither of them. Poor nutrient absorption and stunted growth are the two major outcomes of this.
9 Perennials To Avoid In Your Garden
1: Bishop’s Weed (Aegopodium Podagraria)
Bishop’s weed spreads rather aggressively and is nearly impossible to remove once it’s properly established in your garden. It can create unwanted competition with your other crops and fill the garden landscape quickly, keeping other plants and perennials from shining through.
2: Lily Of The Valley (Convallaria Majalis)
Although lily of the valley is an incredibly beautiful perennial, it’s also invasive, spreading quickly underground and choking out other plants. Don’t let its beauty deceive you, and keep you from seeing the damage it could potentially be doing behind the scenes.
3: Purple Loosestrife (Lythrum Salicaria)
Purple loosestrife can be highly invasive and harmful to wetlands. Believe it or not, this perennial variety is actually banned in some parts of the world due to the damage it can cause to wetlands and swampy areas.
4: Mint (Mentha Spp.)
Yes, mint is technically a herb, but many gardeners plant it as a perennial ground cover and later regret it. It takes over garden beds fast, it’s incredibly hard to get rid of and interferes with the growing ability of other plants within a close enough radius.
5: Obedient Plant (Physostegia Virginiana)
Yeah…you can say the name is quite iconic as it’s probably the least obedient perennial out there. It spreads rapidly and becomes very hard to control once its growth begins.
6: Periwinkle (Vinca Minor)
Despite the wholesome and sweet-sounding name, periwinkles can actually be quite troublesome in the garden. They’re commonly used as ground cover, but they tend to smother other plants when they grow and are super hard to remove.
7: Japanese Knotweed (Fallopia Japonica)
I remember talking about Japanese Knotweed in one of my articles, but I don’t recall telling you guys how damaging it can be. It’s definitely one of the most destructive invasive perennials out there, as it can damage structures and take years to eliminate.
8: Tansy (Tanacetum Vulgare)
Although tansies offer round, vibrant blooms that look quite aesthetically pleasing in the garden, the problem is that they can be invasive and toxic to pets and livestock.
9: Yellow Archangel (Lamiastrum Galeobdolon)
Although yellow archangels look extremely pretty in shade gardens, they spread aggressively and are considerably hard to contain once they’re in their growth phase.
Conclusion
Now that you have a good understanding of how certain perennials damage your garden while appearing like they’re “improving” it, it’s up to you to decide what you want to do about them.
You can either remove them and let your other plants grow in peace or plant alternatives that add to the harmony of your garden instead of taking away from it. Either way works.
That’s not Lily of the Valley
Hi Cindy! You’re absolutely right! Thanks for catching that—we’ve just fixed it. 😊🌿
If it isn’t lily of the Valley, what is it. We had that in our yard when I was growing up and it was called Lily of the Valley!
Hi Pat! I had actually posted the wrong picture earlier, but I’ve since fixed it! What you see now is Lily of the Valley. 😊
Chameleon plant is another to add to your list. Impossible to get rid of.
Hi Sher!
Great addition. Chameleon plant is definitely a tricky one,it spreads like crazy and can be so hard to control. Thanks for sharing! 🌿😊
The picture is NOT Gooseneck Loosestrife (Lysimachia clethroides). It’s Lysimachia salicaria. A very different plant.
Many of the plants you’ve listed are grown commercially and responsibly by cut flower farms.
How much experience do you have with any of these plants? Little if any if you live in an apartment.
Hi Linda!
Thank you for pointing that out! You’re absolutely right about the plant mix-up, and I’ve fixed the image,it happens sometimes, and I really appreciate you catching it. As for my experience, I’ve mentioned many times how I grew up following my mom around her huge garden, learning everything I could from her. I also reach out to friends, family, and followers, not just for this article but for most of my articles, to ensure I’m sharing advice that’s as helpful and relatable as possible. It’s a learning journey, and I’m always grateful for feedback like yours! 🌿😊
Your comment back to Linda Williams was so kind. Her comment to you was very uncalled for! She could have been much nicer and should have been. After all, it’s your work and time put into the article. If she didn’t like it, she could’ve stopped reading it and moved on. It irritates me when people read something and have to be so critical!
Hi Dianne! Thank you so much for your kind words! 😊 I truly appreciate your support, it means a lot.
I know not everyone will agree with everything I share, and that’s okay but I always try to respond with kindness because we’re all learning together! I love hearing different perspectives, but thoughtful conversations always go further.
I’m just happy to keep learning and connecting with fellow plant lovers like you! 🌿💚
I totally agree with you! Linda’s comment was rude, and I guess she needed to feel good about herself! Rita’s response was kind!
Thank you, George! 😊 I really appreciate your support, it means so much. I try to keep things kind and helpful, even when the feedback is tough. At the end of the day, I’m just grateful for this community of plant lovers who are learning and growing together! 🌿💛
Would you mind saying what Zone you are in? I have Centaurea Montana and can’t get it to multiply at all. I’m in Zone 5/6.
Hi!
I’m in Zone 6b! Centaurea Montana usually grows well here. If it’s not multiplying for you in Zone 5/6, try giving it well-draining soil, full sun, and dividing it every few years. Sometimes it just needs a little extra encouragement to spread! 🌸🌿
Please don’t forget Morning Glories!
Hi Donna! 😊 You’re absolutely right!
Morning Glories can be a real headache in the garden. They spread so fast and can quickly take over. They may look beautiful, but they definitely make the list for plants that can cause more trouble than they’re worth! 😊🌿
Vinca vine looks beautiful cascading on a rock wall. Once established you will never get rid of it! It’s so invasive. I hate it now.
Hi Shelly! So true! Vinca vine looks lovely at first, but once it takes hold, it’s nearly impossible to control. It spreads fast and chokes out other plants. Definitely one of those “plant with caution” perennials! Thanks for sharing your experience! 😊🌿
Purple Loosestrife is outlawed in NE. Plantings along the Platte River choke out desirable habitat for water fowl. It will completely take over an island in a channel of the river.
Hi Kathy! That’s a great point! 😊
Purple Loosestrife is incredibly invasive and a serious threat to native habitats, especially in wetland areas like the Platte River. It’s a good reminder of why it’s banned in many places. Thanks for sharing this important insight! 🌿
Definitely; the prior owners of my house had planted it. Small then. Now, no matter what I do, it continues to grow and pop up all over the yard.
Hi Jan! That sounds so frustrating! 😩 Purple Loosestrife spreads aggressively once established, and it’s nearly impossible to fully remove. Even small root fragments can sprout new plants! Regular removal and even smothering with mulch or tarps can help slow it down, but it definitely takes persistence. Hope you’re able to keep it under control! 🌿🚫
I live in Pennsylvania and we have a large eroding bank I would love to cover
Do you have any suggestions?
Robin B
Hi Robin! Great question! 😊 For erosion control, you’ll want deep-rooted, spreading plants that hold the soil in place. Here are some great options for Pennsylvania:
🌿 Native ground covers: Wild ginger, creeping phlox, or golden ragwort.
🌾 Ornamental grasses: Switchgrass or little bluestem—great for stabilizing slopes.
🌸 Shrubs: Red osier dogwood or sumac, which spread and provide year-round interest.
Mixing these together can create a beautiful, low-maintenance bank that prevents further erosion. Let me know if you’d like more details! 🌱✨
I’ll put my Arizona soil up against ANY invasive plant. Arizona will win, no question. Arizona = “hardscrabble farming.” Any advice the author gives needs a disclaimer. “This does not apply in AZ.”
Hi Susan! Haha, fair enough! 😄 Arizona soil really is in a league of its own, tough, dry, and not easily conquered! Some of those invasive plants don’t stand a chance out there. Thanks for sharing! 🌵💪🌿
As far as I can see, the plants in your list are plants that if you have them in your garden and/or yard, you want them there. A ground cover is wanted for that purpose. I plant mint because I want it and yes I plant it in the yard where I don’t care where it spreads. Certain plants you want in the yard and not in the garden. I love violets and dandelions. To me, they belong in the yard and not in the garden. If you want to contain a particular plant, designate an area with a fixed border so that it can’t spread and then you can have it and prevent it taking over a different area.
Hi Elaine! Totally understand where you’re coming from! 😊
If you read the article, I actually explain why each plant can become a problem in certain situations and I give tips on how to grow them safely, like planting in pots or in a dedicated, contained area. When I was a beginner, I didn’t know any better and planted mint straight into the ground… it took over everything! So many others have shared the same experience. It’s really just meant to help gardeners avoid those early mistakes. 🌿💚
Trumpet vine will grow up your downspout and pull it right off your house. It gets to Newport, but doesn’t bloom for me, so , now to get rid of it!
Hi Kathryn! Yes, that vine can be relentless! 😅 It’s super aggressive and strong enough to do real damage, like you said. And if it’s not even blooming for you, definitely not worth the trouble. Good call getting rid of it!