21 Popular Plants You Should Only Grow in Pots

When planting your garden, an important factor to consider is how the plants you choose will interact with one another. There are a couple of factors that make some bad neighbors. It’s good to know ahead of time which ones will take over and which may inhibit the growth of its neighbors. 

We all know about invasives. These plants are usually non-native and aggressive spreaders that crowd out anything growing nearby, most importantly, native plant species. While it would be great if local nurseries kept track, most of the time, it’s up to the gardener to know what not to put in the ground. Popular plants sell, so retailers don’t always care. 

Another issue that can crop up involves allelopathic plants. These release chemicals into the soil, which inhibit the growth of other plants that share the same root space. Some of them are useful or beautiful, but because of this characteristic, it’s better to keep them contained. 

It would be difficult to give an exhaustive list of invasive plants, and many allelopathic plants are sold at nurseries. Very common plants are too, so I’ve gathered some of the more popular offenders. Here are some of the more common plants that are best grown in pots, away from others. 

Fennel

	botanical name Foeniculum vulgare
	sun requirements Full sun
	height Up to 6’
	hardiness zones 4-9

Fennel falls into the allelopathic group. This is a tasty perennial herb, as well as a butterfly host plant. Keep this one around as food for swallowtail butterfly larvae. I love a good butterfly host, but this one should stay in a container. 

Not only are fennel plants invasive in parts of North America, the roots put out chemicals that inhibit the growth of neighboring plant’s roots. This means that the surrounding plants will be weaker and smaller as a result of their proximity to it. Fennel has deep roots, so make sure to give it a large, deep container.

Christmas Fern

	botanical name Polystichum acrostichoides
	sun requirements Partial to full shade
	height 1’-3’
	hardiness zones 3-9

Christmas ferns look amazing in large hanging pots. They are popular choices for hanging on the front porch because they are so low maintenance. Part of what makes them so easy to care for is their ability to thrive in just about any environment. They can handle dry or moist soil and are hardy in a wide range of climates. 

It can be tempting to pop them in the ground when you replace them with new porch dwellers. I will tell you from experience, that once you put these in the ground they will be there forever. In most places, they aren’t listed as invasive, but they form large clumps that can crowd out other plants. It’s best to keep them in containers to limit their aggressive spread. 

Mexican Petunia

	botanical name Ruellia simplex
	sun requirements Full sun to partial shade
	height 3’-4’
	hardiness zones 8-10

These pretty purple flowers are tempting, and they are so easy to care for. Mexican petunias may look sweet and innocent, but they are invasive in most places. These perennials can even create a monoculture if left to their own devices. 

Put these in the ground, and you’re likely to spend the rest of your life pulling them out. Trust me, I speak from experience. Their rhizomatous roots are aggressive and difficult to eradicate. Are they beautiful? Yes. Should you keep them confined to pots? Also, yes. 

Lantana

	botanical name Lantana camara
	sun requirements Full sun
	height 1’-6’
	hardiness zones 7-11

Lantana is another perennial that is very popular in pollinator gardens. It is commonly available at many nurseries and flowers wonderfully with very little care. Be careful about planting this in the ground, though, because in warm climates, you’ll never get rid of it. It is classed as an invasive species in multiple regions.

Lantana is established quickly and can grow very large. They can overpower other contenders for garden real estate in a relatively short time. This plant will grow in a wide range of conditions and sometimes takes over entire forest floors, crowding out native inhabitants. The trailing varieties make great hanging plants, and mounding types look nice in large containers. 

Butterfly Bush

	botanical name Buddleja
	sun requirements Full sun
	height 5’-12’
	hardiness zones 5-9

As an avid pollinator gardener, it’s hard for me to write this one. Butterfly bush will certainly bring pollinators to your yard. More and more every year as it takes over the entire garden. That’s hyperbolic, but you catch my drift (pun definitely intended). Seriously, though, this one spreads and invades quickly. To put it in a pot might not even make enough difference, especially if you don’t deadhead.

There are a lot of arguments for not planting butterfly bush at all. The great panicles of flowers are stunning and full of sweet nectar. Pollinators love them, and all of those tiny flowers, when pollinated, become seeds. And all of those seeds turn into bushes. If you must grow this one, keep it in a container and deadhead like your garden and the surrounding ecosystem depends on it.

Tansy

	botanical name Tanacetum vulgare
	sun requirements Full sun to partial shade
	height 1’-5’
	hardiness zones 3-8

Tansy is an interesting plant in terms of its role in the garden. It has a distinctive aroma that is repellant to some insects. As a result, it is often planted as a companion to various fruits and vegetables. It repels nuisance insects such as squash bugs, cucumber beetles, and some wasps and is very attractive to honeybees. These factors make it a great thing to have your edibles close by. 

Tansy also adds potassium to the soil. However, studies show that it can inhibit the germination of some seeds. This places it with other allelopathic plants, and it’s an invasive species in MD, MN, ID, OR, WA, WI, and WY. It’s best to keep tansy in a large container near your vegetable garden to reap the benefits. 

Mint

	botanical name Mentha spp.
	sun requirements Full sun to partial shade
	height 1’-2’
	hardiness zones 2-10

Mint has many wonderful uses. Their fragrant leaves make delightful teas and work as flavoring for other culinary endeavors. They are hardy and stand up well to the elements. You can grow mint in a variety of exposures and soil types. In the ground, it is also drought-tolerant. 

All of these factors add up to a plant that tends to move in, stick around, and spread out. If you’ve ever planted mint in the ground, you know what I mean. Mint can be aggressive, and once it settles into the garden, it has a habit of crowding out neighbors and popping up in inconvenient places. It’s best to keep mint in a large container. 

Oregano

	botanical name Origanum vulgare
	sun requirements Full sun
	height 1’-3’
	hardiness zones 4-8

Oregano and mint are close relatives, and they present some of the same issues. Oregano is an adaptable and vigorous plant that doesn’t mind an inhospitable environment. Sandy soil and heat are no match for this herb. It will grow well in most conditions, except for soggy soil. 

Oregano also shares some of the less desirable traits that mint exhibits. It can be an aggressive spreader, moving others aside as it does so. It grows by underground runners and if allowed to bloom, can spread by seeds as well. The good news is that oregano makes an excellent container plant. Its drought tolerance means that it can stand up to hot, dry weather, even in a smaller container. 

Horseradish

	botanical name Armoracia rusticana
	sun requirements Full sun to partial shade
	height 2’-2.5’
	hardiness zones 4-8

We are big horseradish fans in my house. The spicy root makes an incredible addition to sandwiches and other foods. The tops aren’t terrible to look at. They have large, broad leaves that grow in a rosette. The plants enjoy rich, moist soil and grow best with six or more hours of sun daily. 

As for why I think you should relegate this one to containers, it’s allelopathic. Similarly to tansy, this plant inhibits the germination of some other seeds. Most notably, a study found that horseradish affects the germination of lettuce. Grow this one in deep, large pots, and eat lots of it!

Lamb’s Ear

	botanical name Stachys byzantina
	sun requirements Full sun to partial shade
	height 12”-18”
	hardiness zones 4-9

Lamb’s ear is a garden favorite in many places. The soft, grey-green leaves look a surprising amount like actual lamb’s ears, which is charming in itself. It makes an absolutely stunning ground cover. That fact alone may tell you why we recommend this one for containers. 

Lamb’s ear can be invasive, especially in warm climates. The stems creep along the ground and form roots at regular intervals. It also produces sweet lavender flowers. If allowed to go to seed, you’ve got a double whammy on your hands, and this plant is likely to travel far and fast. Keep this one in a pot, especially in warm climates where it can be evergreen. Deadhead often. 

Lily-of-the-Valley

	botanical name Convallaria majalis
	sun requirements Partial to full shade
	height 6”-10”
	hardiness zones 3-7

LIly-of-the-valley is said to have been the favorite flower of Queen Elizabeth II of Great Britain. They still grow in the gardens at Buckingham Palace, and find their way into the bridal bouquets of the royal family. They are lovely plants with sweet, innocent, fragrant flowers. They grow in nearly full shade, which is another appealing aspect.

Putting aside the fact that all parts of the plant are poisonous, they are also invasive in many places in the United States. The rhizomes grow quickly in cool, moist, rich soil. If left on the plant, the pretty white flowers will also self-seed, making it a double threat. Or is that a triple threat? Either way, put it in a container or raised bed to keep it where you want it. 

Vinca

	botanical name Vinca minor
	sun requirements Full sun to partial shade
	height 3”-6”
	hardiness zones 4-9

Vinca is a vigorous grower that tolerates poor soil and is drought-tolerant. It has attractive foliage and lovely flowers in shades of blue, purple, pink, red, and white. It’s also very poisonous, so exercise caution when working with this one. All parts of the plant are toxic to humans. 

Vinca, while lovely, is not a plant I will add to my garden. I’ve dealt with it, and it took years to eradicate. Now, it makes a nice hanging plant with its trailing habit, so don’t count it out altogether. However, it is invasive in many places, particularly the Eastern United States, it spreads in all directions, so it’s better off in a pot where it can be contained and regularly deadheaded. 

Lemon Balm

	botanical name Melissa officinalis
	sun requirements Full sun to partial shade
	height 2’-3’
	hardiness zones 3-7

I’m not sure how I feel about this one, seeing that we share a proper name and all. Lemon balm, or Melissa officinalis, is a tasty herb with a strong, pleasant lemony aroma. The essential oil is repellent to many nuisance insects, and the leaves make a lovely tea. It’s a sturdy relative of the mint family (Lamiaceae) and behaves similarly to other members. 

Lemon balm spreads in two ways: by underground runners and by self-seeding. Cutting the flowers before they go to seed can help slow the spread, but sooner or later, if you plant this in the ground, you will have more than you want. Give your lemon balm a nice big pot. It will grow into a lovely small shrub that loves to be pruned. 

Yarrow

	botanical name Achillea millefolium
	sun requirements Full sun
	height Up to 3’
	hardiness zones 3-9

I’ll admit that I am on the fence about this one. But, in some environments, yarrow can be very aggressive. I love this for the cutting garden, and it works there because as fast as it will flower, I will cut those pretty flowers. If this is your purpose, it’s probably ok to plant yarrow in the ground.

Yarrow spreads in two ways, roots and seeds. It re-seeds aggressively if you don’t deadhead it. Even if you do, you’ll want to dig them up every two or three years and divide the roots to thin the plants. A large pot or raised bed is the perfect place for your yarrow.

Bee Balm

	botanical name Monarda spp.
	sun requirements Full sun to partial shade
	height Up to 4’
	hardiness zones 4-9

I have a complicated relationship with bee balm. On the one hand, it is an attractive plant, and when it flowers, the pollinators go crazy for it. On the other hand, like its relatives in the mint family, it spreads like wildfire.   

Bee balm will overrun a raised bed in a year or two. Once it’s there, good luck getting rid of it without starting the bed from scratch. The best place for this plant, in my humble opinion, is in a pot, on a concrete patio, or porch. Choose someplace it can’t re-seed and crowd out everything else around it. 

Foxglove

	botanical name Digitalis purpurea
	sun requirements Full sun to partial shade
	height 2’-5’
	hardiness zones 4-9

Foxgloves are beautiful and dangerous. All parts of the plant are poisonous to humans and animals. But they are truly charming in the garden with their sweet, bell-shaped flowers. Bumblebees adore these blooms, and I love anything that brings bumbles to the yard. 

Sadly, foxgloves are listed in the Invasive Plant Atlas of the United States. There are plenty of alternatives to this plant  in terms of adding vertical interest to flower beds (even some native foxgloves). If none of those meet your needs and you just adore foxglove, plant it in a pot and make sure to deadhead. 

St. John’s Wort

	botanical name Hypericum perforatum
	sun requirements Full sun to partial shade
	height 1’-3’
	hardiness zones 3-8

St. John’s wort is a tempting sub-shrub that works excellently in the mid-ground and has nearly year-round interest. It produces pretty yellow flowers and has an easy-going nature. It loves a moist, but well-drained environment, but it’s truly not particular about soil. This ease of care and adaptability is precisely what makes this a no-go in many places. 

You see, this perennial is self-fertile and produces as many as 100,000 seeds per year. It also has rhizomatic roots that send out branching roots in all directions. In natural areas, it can be a huge problem, pushing out native plant species. Especially in disturbed areas, like your garden, it can take over.

Yucca

	botanical name Yucca spp.
	sun requirements Full sun
	height Up to 30’
	hardiness zones 4-11

Yucca plants are interesting and make a great statement in the landscape. Their tall, spiky rosettes of leaves and flamboyant floral displays are alluring. Especially given their easy-going nature and adaptability. Yuccas can thrive in hot, dry weather. Once again, this toughness is what makes this one pose a potential threat. 

Yucca has aggressive roots and can crowd out other native plants. In certain areas it is incredibly difficult to eradicate once it has taken up residence. Outside its native range, put your yucca in large containers where you can enjoy its beauty and protect the rest of the garden.

Daylily

	botanical name Hemerocallis fulva
	sun requirements Full sun to partial shade
	height 3’-6’
	hardiness zones 3-8

Daylilies are tempting perennials with slender, straplike foliage and large, brilliant flowers. Drifts of these flowering perennials can create a cohesive look in the landscape. In some areas of the country, these plants are fine to put in the ground, but not everywhere. 

In the Mid-Atlantic region, this one is known to naturalize and crowd out native plants that are important to the ecosystem. It carries the invasive label, so keep this plant out of the ground in areas where it’s classed as such. Daylilies are beautiful, but in those areas where it is invasive, they belong in containers only.

English Ivy

	botanical name Hedera helix
	sun requirements Full sun to full shade
	height 30’-80’
	hardiness zones 4-13

The amazingly vigorous growth habit of English ivy might be appealing if you want to cover a wall quickly. But think twice before you pop this in the ground. If it can cover a wall in a matter of two or three years, just imagine what else it can do. Not only does this invasive plant crowd out native plants that are important to local wildlife, but it can carry a bacterial disease, as well. 

It’s ok if you still love this plant and its classic Victorian vibe. It’s a pretty vine and carries a very nostalgic appeal. The best thing is that English ivy, with its shade tolerance, makes a wonderful houseplant. Grow this in a hanging pot for beautiful trailing vines without the threat of invasion. 

Running Bamboo

	botanical name Phyllostachys aurea
	sun requirements Full sun to partial shade
	height 15’-20’
	hardiness zones 4-10

Bamboo is good for a lot of things. It makes an excellent privacy screen. The rustling sound of a breeze passing through is just one of the pleasing characteristics of this plant. Bamboo is a type of grass, and there are two different growth habits. Clumping bamboo will grow larger over time but will stay in one place. 

We are here to talk about running bamboo. There are many beautiful varieties of this large grass, and they can be tempting, but don’t do it. Running bamboos will take over, and you’ll be wrestling them out of the garden forever. While there are native bamboo species, stick with a clumping variety unless you are putting your bamboo in a container.