Invasive Species

8 Invasive Plants to Avoid

Did you know that some of the plants sold at many big box stores, garden centers, and nurseries are invasive species? An invasive species is a non-native species with the ability to grow, reproduce, and spread quickly to push out native species and cause ecosystem damage and/or economic harm. The classic plant examples are Asian honeysuckle and kudzu. Invasive species make their way into our ecosystems in all kinds of ways, but when it comes to invasive plants one of the most common ways they are introduced is through ornamental use.

Many of these plants are beautiful, easy to grow, and quick to establish. That makes them great candidates for low-maintenance landscapes, but sometimes they're just a little too good at thriving, and they can escape into our natural areas and wreak havoc on the environment. Not all easily grown and quickly established plants are invasive though: there are several rockstar hydrangeas, and none of them are invasive (some are even native).

There are two main arguments I typically hear when I encourage people not to buy these plants: “it’s not invasive in my yard,” and “if it were really that bad I wouldn’t be able to buy it”. You might be able to keep a plant under control in your yard pretty well with trimming and weed control, but when seeds or scraps make it into areas with less detailed oversight, they may quickly take off and cause significant problems. I agree that invasive plants should be restricted early and not sold, but regulatory wheels turn slowly. Some states take longer than others to ban species, and some states are more aggressive than others in which species they list. Right now, Indiana actually has no laws restricting invasive terrestrial plants, but a new rule is currently under review to ban the worst of the worst species.

Beyond official regulations, it’s up to an individual nursery, garden center, or landscape company to choose not to use these harmful species, and several companies have begun to self-regulate. Below we've listed ten plants widely available for purchase that should not be planted, and we’ve provided some well-behaved alternatives (*native species are marked with an asterisk). We have stopped using any of these, and we want to encourage you to join us.

Burning Bush

Euonymus alatus

Why it's planted: easy-to-grow-shrub with bright red fall color

What to plant instead:

  • Chokeberry hybrids and varieties*: medium sized native shrub with excellent red fall color, also has white flowers in spring and showy black or red berries in fall

  • Diervilla ‘Kodiak Orange’: medium to large shrub with an orange tint to leaves most of the year followed by brilliant red fall foliage, pollinators like the yellow flowers

  • Dwarf Fothergilla*: small to medium sized native shrub with sweet-smelling spring flowers and a rainbow of fall color

Wintercreeper

Euonymus fortunei

Why it's planted: easy-to-grow evergreen groundcover

What to plant instead:

  • Canadian Wild Ginger*: semi-evergreen native groundcover, spreads underground by roots

  • Allegheny Spurge*: native cousin of Japanese pachysandra, spreading groundcover

  • Epimedium: colony-forming groundcover with good spring and fall foliage color and delicate flowers in spring

Callery Pear

Callery Pear

Callery Pear

Pyrus calleryana

Why it’s planted: inexpensive small tree with tight shape, white flowers, and good fall color

What to plant instead:

  • Hornbeam*: has a tight oval shape and can even be sheared for an even cleaner look, attractive gray bark in winter

  • Hawthorn*: small tree with round to spreading canopy, white spring flowers, and bright red berries in fall and winter

  • Serviceberry*: small tree, often multistemmed, with white spring flowers and tasty dark red berries in early summer, good orange fall color

Privet

Ligustrum species and hybrids

Why it’s planted: low-maintenance, hedge-friendly shrub

What to plant instead

  • Boxwood: evergreen shrub that can be tightly sheared or grown in a more natural shape, somewhat shade tolerant

  • Yew: evergreen shrub that can be tightly sheared or grown in a more natural shape

  • Panicle Hydrangea: showy summer-flowering shrub available in a range of flower colors and sizes, with the right variety selection pruning is unnecessary for an un-sheared but still tidy hedge

Purple Loosestrife  By AnRo0002 - Own work, CC0

Purple Loosestrife
By AnRo0002 - Own work, CC0

Purple Loosestrife

Lythrum salicaria

Why it’s planted: low-maintenance perennials with attractive spikes of fuschia flowers

What to plant instead:

  • Bee Balm*: colony-forming perennials that pollinators love, firework-shaped flowers in mid-summer in shades of red, pink, and purple

  • Blazingstar*: spikes of vibrant purple flowers in mid-summer, very popular with bees and butterflies

  • Turtlehead*: a late bloomer to extend the season with pink or white flowers from August to October

Japanese Barberry

Berberis thunbergii

Why it’s planted: un-kill-able shrub with colorful foliage, thorns make a hedge that keeps people out

What to plant instead:

  • Chokeberry hybrids and varieties*: medium sized native shrub with excellent red fall color, also has white flowers in spring and showy black or red berries in fall

  • Ninebark*: medium to large dark-leaved shrub with arching branches and smallish white clusters of flowers, larger varieties are most suitable for natural styles

  • Diervilla: medium to large shrub with options for colorful foliage, brilliant red fall color, pollinators like the yellow flowers

Sweet Autumn Clematis  By Σ64 - Own work, CC BY-SA 3.0

Sweet Autumn Clematis

Clematis terniflora

Why it’s planted: quick-growing flowering vine, late blooming, delicious smell

What to plant instead:

  • Woodbine*: North America’s native clematis is virtually identical to sweet autumn clematis, just less vigorous with not quite as many flowers

  • American Wisteria*: North America has a native wisteria as well with smaller flowers and slightly less fragrance than the better-known Asian varieties that some consider to be invasive

  • Coral Honeysuckle*: native non-invasive honeysuckle vine, trumpet-shaped yellow and red flowers, popular with hummingbirds

Maiden Grass

Miscanthus sinensis

Why it’s planted: quick-growing, dependable ornamental grass with strong structure and attractive seed heads

What to plant instead:

  • Little Bluestem*: narrow, upright ornamental grass about 18-36” tall with thin, attractive seed heads, good reddish fall color

  • Switchgrass*: upright ornamental grass about 24-60” tall depending on variety, open and airy seed heads

  • Karl Foerster Grass: reliable designer favorite beloved for its tidy basal leaves and stark upright golden yellow seed heads

These are all plants that people loved (and still love) for a reason, and it’s not going to be easy for everyone to let go of them. Fortunately there are great alternatives, and I’m hoping you join us in embracing them. If you want to learn more about the proposed rule restricting invasive plants in Indiana, WFYI has shared some more details along with the full proposed list of banned plants. Still not sure why invasive plants are such a serious problem? The Indiana Native Plant Society does a great job going into more detail and linking to other resources. Got any other recommendations for alternatives to these invasives? Leave us a comment!


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