9 Common Garden Flowers That Are Incredibly Invasive

It’s a common saying in the realm of gardening that “gardeners avoid invasive crops like kids avoid medicine”. And, to no surprise, this is absolutely true! 

While invasive flowers can add this “messy pretty” touch to your garden, it’s typically just not worth the hindrance they cause to other plants and flowers nearby. 

In today’s article, let’s go over a list of common garden flowers that are actually incredibly invasive and mischievous. But, before we get to that, first…

What Makes A Flower Invasive? It’s Easy!

More often than not, invasive flower species are non-native and they spread aggressively through rhizomes, runners, and self-seeding abilities.

They create competition in the soil against local plants, causing them to become weak and often unable to grow properly. 

The worst part about invasive flowers is that they’re super difficult to remove from the ground, and even if you do, they keep coming back. 

1: Orange Daylily (Hemerocallis Fulva)

While daylilies aren’t exactly known for being invasive, it’s the wild varieties that have this unstoppable growth habit. You’ll find orange daylilies commonly along roadsides, and they’re super annoying to get rid of thanks to their dense clump formation.

They’re also mildly toxic to pets, especially cats, so it’s best to keep them out of reach.

Tip: Try your best to avoid wild daylily varieties and instead opt for sterile hybrid ones.

And if you’re trying to avoid future garden regrets, here are more plants you’ll wish you never planted.

2: Baby’s Breath (Gypsophila Paniculata)

Baby’s breath flowers are known for self-seeding rapidly and spreading at a wild pace. They’re more likely to be found in dark corners and cracks in the garden beds. However, their invasiveness can often go unnoticed due to their unique, airy flowers.

It’s also worth noting that dried baby’s breath can irritate skin or cause breathing issues, especially when used indoors.

Tip: If you’re looking to fill up gaps and patchy areas in your garden, opt for non-invasive fillers like astilbes. 

3: Creeping Bellflower (Campanula Rapunculoides)

Like the name suggests, creeping bellflowers spread fast through rhizomes and seeds. They become dense in no time and tend to overpower nearby shrubs and perennials. 

Unfortunately, you’ll either need to remove the root system of this invasive bellflower or avoid planting it entirely. 

Tip: Opt instead for clump-forming Campanulas like Campanula carpatica or Campanula glomerata ‘Superba’.

4: Lantana (Lantana Camara)

Lantanas adapt incredibly fast, but it’s something that doesn’t really benefit anyone. The flower escapes through seed and halts the growth of any plants in close enough proximity.

It’s also super toxic to humas, pets and livestock if ingested (something to consider if you have pets or little ones around).

Tip: Instead of toxic lantanas, opt for non-invasive and plant native pollinator-friendly flowers like milkweed, coneflowers, or coreopsis.

You should also take a look at this full list of toxic plants that don’t belong in your garden—lantana’s just one of several worth avoiding.

5: Obedient Plant (Physostegia virginiana)

Despite its charming name and spiky pink or purple blooms, obedient plant is anything but well-behaved. It spreads aggressively through underground rhizomes, forming dense colonies that quickly take over garden beds and crowd out other perennials.

Tip: To keep it in check, grow obedient plant in containers or use deep root barriers. Regular division is key if you want it to play nice with the rest of your garden.

6: Spanish Bluebell (Hyacinthoides Hispanica)

Spanish bluebells are very popular, and even I have covered them many times in my articles. These perennials typically escape through bulbs and seeds, and they hinder native wildflower growth tremendously.

They’re also mildly toxic if eaten in large amounts, which makes them risky for pet-friendly spaces.

Tip: If you want to grow bluebells avoid Spanish or hybrid bluebells, plant native English bluebells (Hyacinthoides non-scripta) instead.

For more safer, pollinator-friendly options, take a look at these spring-blooming native plants that support your garden without crowding out local species.

7: Morning Glory (Ipomoea Spp.)

Morning glories are subtly invasive, and they spread aggressively through runners and seeds. They have the tendency to take over smaller plants and structures fast, making them not a very safe addition to the garden. 

Also, some varieties have toxic seeds that can be dangerous if eaten, so it’s best to avoid it if you have pets or kids.

Tip: Grow your morning glories in pots and only use annual hybrid varieties if you can. Avoid perennial species like Ipomoea indica, which can also take over.

8: Butterfly Bush (Buddleia Davidii)

While they’re incredibly popular among new gardeners, butterfly bushes are also known for escaping cultivation. They can overpower native species with great ease and leave your entire garden landscape in shambles. 

Tip: Again, the best solution to this is to opt for sterile cultivars like ‘Miss Molly’ or native butterfly bush varieties like buttonbush or summersweet. 

For more plants that can quietly wreak havoc in your garden, take a look at these perennials you may want to stop planting too.

9: Gazania (Gazania Spp.)

Gazanias are super adaptable, and they’re actually banned in certain parts of Australia due to their invasive nature. Unlike other invasive flowers that just spread aggressively, these form entire mats that are hard to control once fully mature. 

Tip: Blanket flowers or California poppies are a much better, non-invasive alternative. Just pick varieties that are more suitable for your region’s climate conditions. 

Let’s Conclude

If you care about your flower garden, its structure, and its aesthetics, you must do your best to avoid planting invasive flowers. These can take over your garden aggressively and completely screw you over in no time. 

If you’re dealing with a plant that’s spreading too fast, here are some native ground covers that stay in their lane and actually support local wildlife.

Trust me, by the time you realize how bad things have gotten, it will already be too late, and getting those suckers out of the ground is a separate headache.