WHITE WOOD ASTER — Eurybia divaricata is the best edge plant for along driveways and walkways. Not only is it a beautiful 2-foot high perennial, topped with small white flowers that nourish our shrinking populations of vital pollinators from September through October, it also spreads quickly along the edge where field sparrows may bend the stems to the ground to eat the seeds.
Now, here’s the best part. Say, after a year or so in October you want more asters for a shady spot, simply break off a tall stem ready to set seed, about 6 inches above the ground, and stick it in the middle of the spot where the next breeze will throw its seeds. Eventually, you’ll be gifting stems to your friends.
The loss of our wildflower-rich grasslands due to development, herbicides, climate change, and competition from introduced plants are impacting native bees and other pollinators, now experiencing simultaneous dramatic declines. Because native wildflower seed banks may no longer exist on their former sites, everyone should help bring back lost native plant species, which is what we are attempting to do at Carpenter Farm Park.
Viable food webs: Native birds and other wildlife specialize in insect diets often consisting of native butterflies and moths. For example, eighty percent of a hummingbird’s diet consists of insects, and ninety percent of our bird populations rear their young on lepidoptera (caterpillars), and arthropods (spiders that also raise their young on lepidoptera). Finally, the butterflies and moths that survive birds and spiders go on to pollinate many of our native wildflowers.
Ninety percent of the insects that eat plants can only eat those with which they co-evolved. So what are the best plants for our native butterflies and moths to eat while in the larval stage? Doug Tallamy, author of Bringing Nature Home, has a list: The number following the plant(s) represents the number of lepidoptera species that feed upon that host genus.
September 2, 2015: As we entered through the gate heading west at the lower fence we counted eight Freeman maple trees growing along the south side of the fence. These trees are especially prolific and are unwanted in a native grassland.
The lateral roots of this tree species can be especially long — up to 7 feet in this case. The trick to uprooting: First, saw through the soil to cut the roots around the stem, then uproot the tree with a large weed wrench. Finally, using a weed wrench and large pliers, extract the remaining laterals.
The most exciting event this season was to have 10 Boy Scouts of Troop 474 join us to remove invasive woodies (sapling tress and shrubs) from the lower meadow. The crew eagerly snipped, cut and pulled roots using pruners, loppers, small limb saws, large pliers, and weed wrenches.
Kudos to Nick Borina and Ryan Borina (Ryan is not in troop but wanted to help) Luke Zarko, Joe Sierra, Nick Serra, Tom Serra, David Burg, Rob Gonzalez, Luke Kowalchuk, Brendan Kossman, Russell Mitard; and special thanks to Scout Mom, Michelle Mitard.
September 15, 2015: Here are the before and after pictures of the 8 multiflora rose shrubs and 8 silver maple saplings removed by the boy scouts plus helpers, all accomplished within three hours.
After the hard efforts of the working crew a section of the meadow is open and ready to seed with native grasses and wildflowers that will provide food and shelter to pollinators, birds and other wildlife.
August 1, 2015: Judy, Kate, Jim and I decided it was time to remove multiflora rose and several species of invasive vines from a large maple on the west side of the lower fence. The leaves of this tree were extremely small, a sign that it was under stress.
We used every tool in the box for this job: folding limb saws, a large weed wrench, loppers, pruners and even sheets of corrugated cardboard to step on and shield against massive volumes of thorny multiflora rose canes.
Everyone cheered when this large old maple tree was released from the vines and shrubs, which would eventually kill it.
The crabapple and mulberry trees are also under stress from invasive vines…
Along the fence lines and in the lower meadow are crabapple trees planted generations ago. Doug Tallamy, author of Bringing Nature Home, reports these trees host over 300 species of beneficial moths and butterflies, an important food source for birds.
Jim cut and hacked away at the huge vines that had rooted beneath the canopy at the foot of this apple tree. Once the leaves of the dying vines — here turning purple — drop off, the tree will have access to the light it needs to survive.
Porcelain berry, which closely resembles our native wild grape, is one of the more invasive tree-killing vines we came across. It is also very difficult to uproot…
It took five of us using a shovel and pulaski axe to dig up this tenacious porcelain berry root at the lower fence line. Unfortunately, any part of the root or vine left in or on the ground could regrow.
This is an earlier before-picture of the south side of the lower fence showing a row of ubiquitous autumn olive shrubs in the foreground and invasive vines covering both the fence and a large mulberry tree in the center back.
In this after-picture taken during the first two weeks in August… we cut/removed the invasive shrubs, and uprooted most vines in preparation for seeding native grasses and herbaceous wildflowers.
We prepared the ground between the double fence line for a garden by smothering weeds with plastic sheeting. One of the plant species considered was swamp milkweed for attracting Monarch butterflies.
People often ask what evergreen shrubs and trees are good for year-round screening that also benefit wildlife. This comprehensive list is from The Living Landscape by Rick Darke and Doug Tallamy.
Chamaecyparis thyoides Atlantic white cedar – useful along streambanks; larval host for rare Hessel’s hairstreak
Juniperus virginiana Eastern red cedar – juniper cones provide important winter food for cedar waxwings; foliage supports many specialist butterflies like the juniper hairstreak
Pinus rigida Pitch pine, Pinus strobus White pine, and Pinus virginiana Virginia pine – seeds provide significant wintering food for many mammals and birds; support 210 species of caterpillars needed for bird nestlings
Ilex glabra Inkberry and Ilex opaca American holly – excellent pollen and nectar source for native bees; produce copious berries for winter birds
Kalmia latifolia Mountain laurel – some value for pollinators
Rhododendron maximum Great laurel, rosebay rododendron – valuable cover for wildlife
July 25, 2015: Karin, Judy and I cut and uprooted six multiflora rose shrubs, which provided support for dozens of invasive vines that reached high into two large trees — mulberry and black walnut — at the far end of the fence.
After uprooting the autumn olive we stripped the mowed area south of the fence of numerous honeysuckle root crowns, and porcelain berry, oriental bittersweet, wild grape and creeping euonymus roots between the fences before laying black sheeting.
In preparation for more plastic sheeting, we pulled roots from the grassy area south of the west portion of fence that had also been cut with a brush hog and mower. This is where poison ivy, spotted knapweed and honeysuckle bushes had infiltrated the cool season grasses.
July 29, 2015: We laid and stapled black plastic sheeting over the clearing to smother existing growth by inhibiting photosynthesis. Once devoid of cool season grasses and weeds we will remove the plastic to broadcast native grass and wildflower seeds.
July 3, 2015: Various methods exist for eliminating invasive weeds from a field of tall grass. Volunteer Susan Guarlnick cut, removed and solarized invasive brown knapweed in the lower meadow using pruners.
Selective Cutting/Solarizing Spotted Knapweed Seed HeadsThe following day I cut and removed large clumps of brown knapweed flowers and seed heads using a sickle. Faster than with a pruner, I was still able to selectively leave wildflowers like black- eyed-susan and goldenrod untouched.
After mastering the art of cutting and uprooting a smaller multiflora rose, Michelle Mitard and her two sons Russel and Kyle eliminated a large shrub that hid the newly blazed trail.
Once the shrub was removed the trail came into view.
Russel and Kyle are boy scouts who will receive service points for their volunteer work.
July 4, 2015: A line of small autumn olive shrubs marked the outer edge of the former horse paddock. Although attractive, these shrubs are not native and are spreading by birds throughout Long Island.
Debbie Hanley and Jim Bentson cut eight small autumn olive shrubs, uprooting them with a large weed wrench. Later, lateral roots were extracted (unfortunately, not entirely) to prevent regrowth from any remaining segments.
July 8, 2015: Approaching the lower fence, I discovered a tree hidden behind multiflora rose, oriental bittersweet and porcelain berry. Wearing thick leather work gloves, I spent an hour or two cutting down the shrub and vines with long loppers.
Once freed from the tangle of invasive plants the tree turned out being native black walnut. These trees have the reputation of producing chemicals that inhibit plants from growing beneath its canopy. However, it appears non-native invasives are far from being sensitive.
The old fence with its narrow gate was an obstacle for the crew and machines that mowed the trail through the meadow. It turned out to be a double fence line where invasives had established a tangled foothold within the ten feet of space separating them.
Thanks to the powerful efforts of Karin Ralph, a twenty year landscaping professional, and farmer Jim, we cut and removed multiflora rose, oriental bittersweet, porcelain berry and a new arrival, creeping euonymus, from between the two fences, widening the meadow’s entrance.
July 2, 2015: Thank you, Shawn C., Matt, Blaise, Shawn T., Jim, Owen, and Dave from Huntington’s General Services for the great work you did cutting amazing trails at Carpenter Farm Park. And thank you Keith, Joe, David, Christian, and Margo for making it happen.
A gentle walk through this very beautiful landscape starts at the open park entrance where the trail begins.
Walk down a winding trail to this heritage crab apple tree and enjoy its shade.
This first meadow adjacent to the former horse paddock will be restored to native grasses.
Pass through this gate and discover the beginning of the greater meadow as you follow the trail down its gentle slope.
The trail along the north border meanders between the woodland and the grassland.
As the trail circumvents the meadow it switches back uphill along the south side.
This is a partial view of the meadow from the top of the hill with heritage crabapple trees in the background.
June 20, 2015: An infestation of purple flowering brown knapweed was found in an open area between the paddock and lower fence. Marion Cristie, Deborah Hanley and Judy Lom pulled and cleared out this highly invasive plant species.
According to Wikipedia, the roots of brown knapweed exude an herbicide to inhibit competition by a wide range of other plant species. Consequently, when knapweed replaces native grasses, soil erosion and surface runoff increase.
We soon discovered a large patch of Japanese stiltgrass growing behind the area cleared of knapweed. Most commonly an invader of forested floodplains, Japanese stiltgrass is found in ditches, forest edges, fields, and trails.
Because we needed a hidden yet convenient spot to solarize the clear bags of knapweed, we attempted to smother out the stiltgrass and cook the knapweed by laying the bags over the patch of grass.
June 26, 2015: We uprooted this multiflora rose shrub growing into the trail, plus five additional shrubs to the right of the photo.
Judy Lom and I cut the canes above the ground high enough for the weed wrench to grab. Then we sawed a circle in the ground around the stub to sever the lateral roots. The large weed wrench uprooted the plant, and we pulled the remaining laterals.
Once all the shrubs, poison ivy and English ivy were gone I sowed the open ground with Indian grass seed. This area receives plenty of morning sunlight for growing native grass.
June 27, 2015: Barbara Wildfeir worked on the multiflora rose, Oriental bittersweet, porcelain berry and maple trees east of the trail and north of the upland fence, opening up this impassible area.
Still need to remove English ivy from along the ground before sowing seed. Looking good.
Along the fence that transects the Park’s upland trail, millions of garlic mustard seed pods were ready to disperse their seeds when volunteers with the Invasive Plant Sub Committee of Huntington’s Conservation Board went to work.
June 10, 2015: Volunteer Kate Levine helped pull a large section of non-native, highly invasive garlic mustard. Many of these invasive plants are edible, which accounts for this European invasive being here.
Pictured here after removing the stand of garlic mustard. Eventually the entire infestation, running several hundred feet long and roughly 50 feet wide on both sides of the fence, was cleared of this highly invasive plant.
The stand of garlic mustard northeast of the fence was removed by Denise Harrington and her daughter, Jenna. This biennial herb blooms and produces seeds only at the end of its second year when it uproots easily, but the seeds must be bagged & solarized.
After pulling the garlic mustard we discovered English ivy hidden beneath. Removing that, however, can wait until late fall when vines are easier to reach. Because English ivy doesn’t produce its toxic ripe berries until late fall, there’s no rush.
June 12, 2015: Anne Meyer (pictured) and her husband Rich uprooted over 100 seedlings and small saplings of Freeman maple (hybrid of red and silver maples) with the use of weed wrenches. The largest sapling was nearly 12 feet tall.
Pictured here in the meadow adjacent to the old horse paddock are the remaining maples after the first pull. There’s still more maples in this field and much more plus invasive shrubs in the larger meadow further down the trail.
Can you find the trail? This is what remained of the upland trail after woody and herbaceous plants took over. The invasive multiflora rose outcompetes native raspberries, and mugwort out-competes native goldenrod; but native poison ivy is also an issue on the trail.
June 19, 2015: Multiflora rose is widespread throughout this park. The week before this picture was taken these very sharp, thorny shrubs were covered in white flowers. Now, millions of small red berries will grow to disperse new seed.
The path opened up once the multiflora rose was cut to the ground and removed. We seeded the bare soil with native warm season grasses to prevent invasive woody plants and other weeds from reseeding. Eventually the trail will be routinely mowed.
June 20, 2015: Poison ivy was found in several places along the upland trail; their white flowers had already grown and died. Now they are producing small green berries, which will ripen to off-white.
Cautiously covered from head to toe I uprooted all the poison ivy along the upland trail. We are the only known species allergic to poison ivy. Birds especially enjoy the berries, which is how the plant spreads.
Poison ivy is a native Long Island plant species and grows best along our woodland edges and trails where it climbs trees to reach sunlight at the top of the canopy.
Upland trail without poison ivy and multiflora rose. Today, the upland trail at Carpenter Farm Park is less obscured by shrubs and poison ivy — at least for now — due to the efforts of its dedicated volunteers.
On the last day of May I walked through my backyard woodlot to see what plants were coming up. Since I’ve succeeded in eliminating most invasives I happily discovered native Canada mayflowers, Mayapple, wild geranium, Solomon’s seal, enchanter’s nightshade, goldenrod, trillium, Virginia creeper, tulip and sassafras trees and small shrubs of raspberry and blackberry.
White wood aster is appearing throughout and is doing its job of shading out invasive seeds. In some open spaces, however, invasive seedlings are nudging their way through. I discovered the non-native Indian strawberry, which at first glance I took to be a native strawberry species — but with smaller, rounder red fruit. I uprooted and collected the plant and added it to my solarizing bag of weeds sitting out in the sun. One thing that struck me was how similar the leaves and runners looked to native raspberries, but minus the prickles.
Seeds of invasive plants find their way to my property from my neighbors, brought there from their neighbors… and so on. Typically, when land is disturbed and open up for yards and lawns, the native trees, shrubs, ground cover and deep mulch that once served as barriers to slow the movement of bird-transporting and wind-borne seeds also shaded seeds from germinating. One might notice that sun-loving invasives don’t generally penetrate large, mature forests, except around the edges. This is known as the edge effect.
What might serve as a buffer between neighbors could be a fence or low hedge to demarcate property lines, but seeds, runners and rhizomes easily cross the border. What’s worse are weeds that spread when grass clippings are collected and dumped in the corner of buffer zones where they grow onto neighbors’ properties. That’s why clippings should be left on lawns. With or without the help of mulching mowers, lawns should be mowed weekly during the growing season. The general practice is to mow the grass when it is 3 inches high and, following the 1/3 rule, cut off no more than 1 inch of that height. Routine mowing will help keep weeds such as mile-a-minute weed in check. Three inch high grass will shade many weed seeds, preventing germination.
The ubiquitous tree-of-heaven seedlings are everywhere except under my beautiful white wood asters, which is one of many reasons why I love this plant. White wood aster is an aggressive native Long Island species that grows in partial and dense shade under deciduous trees. I find rabbits nibble the leaves, native bees and other pollinators enjoy the nectar in late August when little else is blooming, and native sparrows eat their seeds in the fall.
Early last July I marked out a 7′ x 8’area in the woods that contained 135 tree-of-heaven seedlings, uphill of a small patch of aster. By August the count was 70, and only 3 seedlings remained by September 5, 2014. So far this year the size of the aster patch has more than doubled and is moving uphill, plus a large branch from a native spicebush is adding more shade to the area. Today I counted only two very small tree-of-heaven seedlings. So whenever I spot these seedlings I decide whether the shade is dense enough to halt its growth or pluck it out. To uproot them I use a hand-held weeder or a nearby twig to loosen the soil as I pull each small stem and root. The roots are so viable that if laid on the ground to dry they can re-root.
The other ubiquitous invasive I keep finding is garlic mustard. Some are the first year’s seedlings, which I simply uproot and leave, and uproot and solarize those with flowering stems and seedpods. I’m careful not to pull out anything I don’t recognize, but will seek help online to identify the plant — as I did when I first spotted what turned out to be white wood aster. For really tricky IDs try Flowers Forums.
Last year I let an area of wild blackberries grow and then cut them back early this year to plant some arrowwood viburnum and elderberry. Now the blackberries are growing out-of-control and I wonder what species they are. Two likely candidates are our common native Allegheny blackberry or some non-native species. An online search indicates that they all have three and five leaflets and ribbed canes. Either way I decided (wisely, I think) to dig them up.
The large stems of blackberries have deep root crowns that must be dug out or pulled with a large weed wrench (available online). The horizontal rhizomes that spread laterally from beneath the crown should also be removed, since young shoots emerge from them. I used a hand weeder to get under the shoots and pull up the rhizomes. Will return in a few weeks to remove new growth as many roots and seeds still remain in the ground.
So the question arises, what to do about unwanted or nuisance native species that benefit wildlife but get out-of-control. I’m talking about poison ivy, pokeweed, grape ivy, and Virginia creeper. My thoughts are that where these plants are growing or likely to grow should be the determining factor. Poison ivy and pokeweed…not where people and pets may wonder; grape ivy and Virginia creeper…not near wanted trees and shrubs.
Lesser Celandine or Fig Buttercup It’s the last day of April, 2015 and beautiful 9 petal bright yellow buttercup flowers cover lawns, hill sides, stream banks, bogs and anyplace ground cover can grow. Uprooting one of the multi-stem plants reveals the cluster of tubers that identify it as fig buttercup, also known as lesser celandine — a native European invasive to Long Island.
A website search discovered that this recent, fast growing plant is exploding in the Pacific Northwest and beginning to do so here in the Northeast. And as with many of our invasives this plant is edible. The tubers, pulled before and after the flowers bloom can be boiled, roasted, and hot pickled. As with harvesting young invasive garlic mustard leaves, don’t be concerned about exhausting the supply.
To slow the rapid growth of fig buttercup, start removing the plants as soon as they can be identified. Hand pull plants before they set seed or form bulbils. The stems of the heart shaped, wavy edged leaves, which may be solid green or with deep plum blotches, can be easily grabbed at the ground, and gently yet firmly wiggled and slowly pulled to uproot the tubers. If the ground is compact use a hand weeder garden tool. Cook or solarize the tubers to destroy them.
Garlic Mustard The young sprouts of the first year’s growth remain relatively small throughout the growing season and don’t flower. In late April/early May of the second year the plant matures with small clusters of white flowers at the top of each stalk. Uproot and leave the small first year’s seedlings on site. Uproot and solarize all other stages, beginning with the flowering stage of this plant to prevent seedpods from developing and dispersing.
These flowering stems will continue to grow and produce seedpods — even if the entire plant is uprooted and composted or left on the ground and not destroyed. But first, because garlic mustard is edible, you may want to pinch off and cook the first year’s growth or the tender stems several inches below the young flowers in the plant’s second year. Then uproot, solarize and dispose of the rest yard waste collection.
Collect a bag of the flowering stems with the tender leaves and even the seedpods for a delightfully pungent green vegetable side dish. Saute and prepare, as for broccoli rabe. For a sweeter flavor, add orange or mango juice, cover, and steam for a minute. Garlic mustard also makes a tasty pesto.
Japanese Knotweed This shrublike plant can grow to over 10 feet tall. The stems are smooth, stout and swollen at joints where the six inch leaves meet the stem. Leaves are oval to somewhat triangular and pointed at the tip. In mid summer, small white sprays of flowers are followed by small winged seeds.
Japanese knotweed seedlings are edible. According to Wildman Steve Brill, “You can eat Japanese knotweed shoots from mid-April to early May, before the plant gets tough and woody.”
Juvenile plants can be hand pulled and should be done routinely throughout the growing season. Use a pulaski axe to remove the larger plants, including all roots and rhizomes. The roots make a pleasant and healthy tea and are known to cure Lyme’s disease. Any portions of the root system not removed will potentially re-sprout. All plant parts and seeds should be bagged, solarized and disposed of prevent them from reestablishing.
Click here for more information about uprooting herbaceous plants.
Long Island is home to both native and non-native vines. For instance, while our native poison ivy is considered a noxious weed by many, it is only so for people who suffer from rashes after touching the leaf, vine or root. Animals don’t have the same reaction, and in fact the berries are a good food source for them. Poison ivy is listed here among the non-native invasive plants because it grows alongside the truly invasive plants such as oriental bittersweet, winter creeper, English ivy, Japanese wisteria, honeysuckle, porcelain berry, mile-a-minute, and kudzu, and could easily be touched or brushed against by someone attempting to remove one of these non-native species. Another native vine is wild grape. While the berries are a feast for birds, the vines can bring down limbs and eventually kill trees from their dense leaf cover over the canopy, shading sunlight from host trees. (The best season for severing vines from trees is winter when other plants, which could impede access, are dormant. Click Vine Removal for details.)
Most Long Island soils harbor viable seeds from their arrival via wind, birds, or mammals years to decades ago. Under the right circumstances — exposure to sunlight being one — these seeds (possibly noxious weeds or more ivy) will quickly germinate and grow.
So, soon after removing vine roots, cover the ground with mulch (a thick layer of leaves) or replace them with native, shade loving plants (plugs or seeds) such as white wood aster Eurybia divericata, and then mulch. This hardy, fast growing species is a beautiful shade loving weed suppressant. It self-seeds, blooms throughout September and is a source of nectar and pollen for native pollinators. Click Native Plants in Recent Posts:
Oriental Bittersweet: The vine of this species can eventually grow large enough to aggressively entwine trees and other plants. The roots are bright orange; flowers small and greenish-yellow; and fruits are pea-sized capsules that change to bright yellow and split open when ripe, revealing a bright orange-red berry within.
Winter Creeper: Also known as creeping euonymus, in winter this evergreen vine produces a four-lobed pale green pod-like berry, which splits open to reveal the fleshy-coated orange seeds, one seed in each lobe. It often grows along with English ivy and should be removed in the same manner.
English or Common Ivy: An infested tree will exhibit decline for several to many years before it dies; and the added weight of vines makes trees susceptible to blowing over during storms. Cut vines at the foot of the tree and pull them from the ground for at least 2 feet around the tree. Gathered vines can be piled up and flipped semi-monthly until they desiccate.
Asian Wisteria: Beautiful lavender flowers distinguish this vine, and is the reason this exotic species was brought to our shores nearly two centuries ago.
Cut and pull the vines and roots from the ground to effectively remove this plant. The twined vines should also be cut from the trunk. Because this is a difficult plant to control, all the plant material should be removed and discarded, as even the cut vines can set roots and regrow.
Japanese Honeysuckle: Several non-native species of this plant include shrubs and vines; may produce red or black berries; and have yellow, pink or red tubular flowers. Common traits: hollow pith stems, opposite, oval leaves with smooth margins (leaf edges).
The roots grow laterally just below the surface of the ground. Pull out all parts of the root to effectively control the plant. Revisit site every few weeks during the growing season to remove new growth from any remaining roots or seeds.
Porcelain Berry: Similar in appearance to wild grape–even with tendrils–except that the pith (center of the vine) of porcelain berry is solid white; mature bark does not peel; berry colors include white, yellow, lilac, turquoise, green and pink, eventually turning dark blue, and the underside of the porcelain berry leaf is always glossy.
Remove and dispose of the entire root (often many feet long) and berries. Check on regrowth semi-monthly and remove suckers and seedlings as they occur.
Mile-a-Minute: Leaves of these thread-like vines grow quickly to cover and obscure sunlight from shrubs and young trees, interrupting plant photosynthesis.
Because this weed is an annual the root will not generate new growth. However, the seeds are prolific. Remove the barb-bearing vines (be sure to wear thick gloves and long sleeves) in early August, just prior to flowering; bag, and allow to cook in full sun. Revisit the site annually to check for new growth.
Kudzu, aka The Vine That Ate the South: KUDZU AND GIANT HOGWEED HOTLINE: Residents should take photographs of suspect kudzu or giant hogweed plants and email them to email@example.com . You can also call 845-256-3111 to report.
Get expert help from NYSDEC by calling the hotline noted above before attempting to remove this invasive.
Poison Ivy: Most people recognize the three leaves of poison ivy. If you need a reminder, google search the name with “images” to see hundreds of photos. This picture was taken of the vine in winter without leaves. Here you’ll see the root hairs that attach to the tree. If allergic to the leaves of poison ivy you’ll want to protect yourself from the vines as well.
Notice that the vine in this photo is starting to encircle the foot of the tree. Cut, remove and dispose of this portion, and extract as much of the root as possible. Keep in mind that poison ivy is native to Long Island, and unless it is creating a health risk leave it for wildlife to enjoy.
Many of the trees we see growing on Long Island are highly invasive and non-native — commonly Chinese exotics brought here over 200 years ago. Today, most Long Island soils harbor viable seeds dispersed from their descendants via wind, birds, or mammals years to decades ago. Under the right circumstances — often sun exposure when land is cleared — these seeds will germinate and grow to out-compete native species.
Long Island’s invasive trees include the ubiquitous tree-of-heaven, Japanese angelica, Norway maple, and sycamore maple, plus some newcomers such as glossy buckthorn and Callery pear. Tree Control will address removing small seedlings and saplings — defined as young trees four inches or less in diameter at breast height. Larger tree removal may require a town permit and some trees may need treatment before cutting to prevent roots from sending out numerous sprouts.
Soon after removing tree seedlings and saplings, cover the open ground with mulch (a thick layer of leaves) or replace them with native, shade loving plants (plugs or seeds) such as white wood aster Eurybia divericata, and then mulch. This hardy, fast growing species is a beautiful shade loving weed suppressant. It self-seeds, blooms throughout September and is a source of nectar and pollen for native pollinators. Click Native Plants in Recent Posts:
Ailanthus altissima, tree-of-Heaven aka tree from hell, is very invasive. It is often confused in appearance with our native sumacs and black walnut. The trunk of tree-of-heaven is smooth (no ridges) and blotchy — resembling pig skin. However, the outstanding difference is the single “tooth” at the base on the otherwise smooth margin of the leaflets. Black walnut bark is deeply ridged and the leaflet margins are toothed.
The tree-of-heaven is dioecious — meaning trees are either male or female. Annually, the females can produce 300,000 or more wind dispersed seeds, which deposit on open ground and germinate by the hundreds or thousands in large patches for great distances downwind of the trees. The female can be recognized by the feathery-looking seed stems that remain at the crown of the tree through the fall, winter, and early spring after the seed pods (samaras) have dropped. Since the tree aggressively sprouts when cut, the trunk is often girdled to kill it a year or so prior to cutting down. Click Tree Control for ideas on removing seedlings/saplings.
Acer platanoides or Norway maple is similar in appearance to sugar maple. The easiest way to identify this tree is to break the leaf at the node where it joins the stem (petiole). You’ll notice white sap at the break, whereas saps from other maples are clear. Also, the point tips on Norway maple leaves have fine “hairs”, while the tips on other maple leaves are rounded.
The shallow roots of this species allow for simple removal of young trees and seedlings. See Tree Control.
With Sunday (April 12, 2015) being the first sunny and warm day of the year, four volunteers agreed to cut a dense thicket of oriental bittersweet from a stand of sassafras and and black birch trees in a small wooded area at Caumsett State Park on Long Island’s North Shore. They wore thick gloves and were equipped with several large loppers and limb saws.
The old adage to always use high quality tools came to mind as we managed to ruin two large loppers in no time, and the rechargeable sawsall’s battery failed to hold a charge. Lesson being, always check your equipment before starting.
These bypass loppers are too lightweight to cut thick bittersweet vines, and forcing them only damages the tool. The loppers twisted, resulting in a gap at the scissor end.
In the process of removing invasive plants the question arises, what to do with the plant material containing viable parts. To prevent reestablishment and spread of the species this material must be properly managed. The best time to remove invasive plants is before plants flower and produce seed. Seeds can lie dormant in the ground for decades until conditions such as soil disturbance, light, temperature, and precipitation are such that the seeds have an opportunity to germinate. It is important to routinely monitor the site cleared of invasive plants until desirable and durable native species become established to out-compete the invasives.
Invasive annual and biennial flowering plants: Timing is critical to successfully control invasive plants. In many cases once a plant flowers or bolts it will produce seeds even if the plant has been uprooted but left on the ground or even composted. The annual mile-a-minute, and garlic mustard, a biennial (meaning the plant lives for two years before it produces seed in the second year prior to dying), typically invade Long Island soils. The best time to uproot these and similar plants is as small seedlings before evidence of flowering (in the first year for biennials). These uprooted seedlings can be left on site or composted. Check for new growth weekly, and flowering stems must be uprooted, solarized and disposed.
Solarize the plant waste by placing the stems, flowers and seeds in clear plastic bags and store in full sun. Black bags smother plants by excluding visible light so the contents don’t gain as much heat, but they do stop photosynthesis, which kills the leaves but not the seeds. Tie and place the clear bags in the sun to trap solar radiation until the seeds have cooked, which generally takes place at 125 F degrees — although temperatures and time varies by species. This process may take a month or two before the wilted plants can be safely disposed.
Invasive Perennials: Perennial plants, including small flowering plants and grasses, are capable of out-competing native plants. Since these non-woody herbaceous plants die back yearly to return in spring from their root-stock, the roots/rhizomes of plants such as Japanese knotweed must be uprooted prior to seeding to prevent the plants from spreading. Pull or dig up roots and bag the stems, flowers, seeds and roots/rhizomes. Solarize as above until the roots/rhizomes have wilted. Some flowers and seeds remain viable once pulled, and should be bagged immediately, solarized and disposed.
Invasive Trees, Shrubs, Woody Vines: Prior to flowering, seedlings and saplings can be pulled and left in place with roots exposed to dry. The larger material can remain on site as a brush pile but should be flipped or turned occasionally to expose roots at the bottom of the pile. Once dried, the wood can be chipped for mulch or composted. If removed during or after flowering occurs, cut out the flowers, fruit and seed parts, and dispose. Do not home compost or leave on site. Some vines and seedpods such as wisteria and porcelain berry stems remain viable once pulled, and should be bagged immediately, solarized and disposed.
Fallen autumn leaves benefit trees and shrubs in several ways. Woody plants live from the nutrients provided them by the leaves that accumulate around their feet in autumn. Living organisms, including microbes and earthworms, help create nutrient-rich humus by digesting organic material, such as leaf litter and other soil detritus, to feed the trees with needed nutrients. Consequently, the entire ground becomes a living, breathing, complex ecosystem, where water, oxygen, carbon dioxide and minerals are exchanged through the activity and interaction of living organisms.
Leaf mulch also protects trees and shrubs from excess evaporation by blanketing the roots. When we rake or blow leaves away from trees we leave the ground bare of insulation and life and are forced to replace missing nutrients by applying inorganic fertilizers. Bare ground invites invasive, light-seeking seedlings to grow. Native plants such as native asters and goldenrod, however, grow through the leaves to trap and hold them in place.
Above: in the foreground is native white wood aster, Eurybia divaricata. This species of aster is a beautiful shade loving weed suppressant; blooms throughout September; and is a source of nectar and pollen for native pollinators.
Below: The 5 foot tall plant in the foreground is a beautiful Joe-Pye weed Eupatorium, growing in front of a native eastern redbud Cercis canadensis tree. Growing up to 16 feet high, this tree — whose rose colored blossoms flower in spring — is often planted as a small ornamental.