We can be sticklers, curmudgeons, even worrywarts when discussing what is appropriate for fall color and holiday flare.

It's just not Thanksgiving for some of us unless garlands of bittersweet are entwined around the centerpiece. And who hasn't admired, at some point, the bright red leaves of burning bushes that are now profligate across the Connecticut countryside?

Reality check here: Some of the most common horticultural harbingers of the season are not native to New England but are dreaded invasive species, the stuff that keeps naturalists and conservationists awake at night. They are an anathema to Drew Kenny and Mary Tomassetti, landscape professionals at Landscape Specialties in Centerbrook, a design and build service that specializes in native plants and naturalized settings.

"I think we should all take some responsibility on our own shoulders to know what's an invasive plant, what are they doing to the ecosystems around them," says Kenny says, who lives in East Lyme. "Invasive plants are a major problem here."

Invasive species are plants, insects and diseases that didn't originate here, but they sure like it, and without any natural predators they are silently disrupting the balance of things by crowding out what ought to be growing here instead.

Some were brought here by good intentions, government planting programs and consumer demand, others hopped a ride on vessels, pant legs and other species. Foraging birds, other animals and hurricane force winds continually help spread the offspring.

For those who like lists, the Early Detection and Distribution Mapping System (EDDMapS) offers all sorts of metrics of the vegetative invasion. Japanese barberry, multifora rose, oriental bittersweet, winged burning bush and autumn olive are the top five in the state, based on reports, but species found in every county include Norway maple, Canada thistle, garlic mustard, crown vetch and ground ivy.

"After Hurricane Sandy, I think people are going to be looking differently at how the massive weight of invasive bittersweet, which grows up trees and strangles them, has weakened pines and other trees," says Tomassetti. "Oriental bittersweet chokes out native ground cover, too."

If you're looking for a little post-turkey exercise this weekend, get outdoors and attack the bittersweet. The Catch-22 is that tugging down the berried vines now only helps to spread more seeds. But Kenny says that's not an excuse to put off collecting and removing the stuff. It means spreading out tarps to collect the berries, bagging everything and tossing it into the trash, not a compost pile and certainly not a neighboring ditch or wild patch of woodlands.

"One of the biggest reasons for plants spreading across the state is because someone has tossed them in a soil bank or town compost supply," says Kenny.

"The best time to get started with removing invasives is when you get started," adds Tomassetti, who recently helped Master Gardener interns remove oriental wisteria, not yet on the invasives list, but nonetheless a ground hog, around Gillette Castle.

It's not that difficult to come up with a long list of better alternatives to ubiquitous burning bush, or winged euonymus, which is the red-leafed shrub we see all over yards, roadways and in the wild right now. Kenny and Tomassetti recommend bayberry, winterberry, blueberries, fothergilla, clethra, witch hazel, grey, redosier or silky dogwood (who knew there were so many choices beyond Kousa and native flowering dogwood?), elderberries and rhododendron as shrubby alternatives.

"Winterberry likes wet feet and is naturally an understory plant," says Tomassetti, who loves to decorate her house with the berried branches. "Plant it in a more sunny location for more berries."

One of the frustrating attributes of invasives is that even the deer won't eat them, which makes them more tempting to plant. Kenny recommends andromeda and enkianthus, a couple of non-native, but non-invasive alternative shrubs. He also says everyone should have at least one sugar maple in their yard. For vibrant fall color in a native small tree or large shrub, plant a sourwood or sorrel tree, native to southern Appalachia.

"If you want to make a small difference, figure out what's growing in your outdoor space and make some changes," says Kenny. Landscape Specialties welcomes questions, plant photos and comments from gardeners at its website, www.landscapespecialties.net and its FaceBook page.

Looking for more info?

Start with Connecticut Invasive Plant Working Group, www.cipwg.uconn.edu.

See detailed plant information and maps at USDA's PLANT database, http://plants.usda.gov

Check out the Center for Invasive Species and Ecosystem Health, www.invasive.org.

Suzanne Thompson of Old Lyme has a weekly radio show, "CT Outdoors," on WLIS 1420/Old Saybrook and WMRD 1150/Middletown and online at www.wliswmrd.net, Tues., Sat. and Sun. Reach her at suzanne.s.thompson@sbcglobal.net.