Invasive Plant Inventory 21St Century Planting Design and Management

Tree of Heaven, Ailanthus altissima

Species characteristics: • Deciduous Tree • Size: up to 80 feet • Flowers: clusters of yellow-green flowers at the ends of upper branches • Leaves: pinnately compound with 11-14 leaflets • Fruit: seeds develop in the fall, each seed is con tained in a sumara, yellow green changing to orange red in fall, brown in winter • Bark: gray with a snake skin like texture, lenticles

WINCHESTER What makes this plant so aggressive? HIGH SCHOOL • Rapid growth rate, saplings can grow 3-4 feet per year • Mature tree can produce 350,00 seeds per year • Seeds are transported by wind and water. • Roots give off a toxin that can inhibit the growth of other plants. • Root sprouts up to 50 feet from trunk. N Why is this plant so damaging to native plant communities? It out competes native species for light. It forms impenetrable SHORE ROAD thickets and tolerates adverse soil conditions.

SKILLINGS ROAD 0 50 100 200 Factors that limit species growth: It is intolerant of full shade.

Management strategies • Hand pulling of seedlings. • Cutting twice per year, once in June, and again September 15th. • Herbicide application, cut trees and apply undiluted

GRIFFIN triclopyr (Brush-B-Gone) to the stump or cut and PHOTOGRAPHY MUSEUM spray resprouts.

JENKS CENTER

POLICE STATION Species characteristics: • Deciduous woody twining vine FIRE • Size: Can reach 18 meters in height STATION • Flowers: female plants produce small greenish flowers • Leaves: variable in size and shape, alternate arrangement, broadly oblong to sub orbicular, tip acute to rounded, base MOUNT VERNON STREET cuneate to obtuse, margins finely toothed, glossy, yellow to gold fall color TOWN HALL • Fruit: 6 to 8mm long, change from green to bright yellow, after ripening the yellow outer covering splits open to reveal a red aril • Root: Outer surface of roots has a characteristic bright CONVERSE PLACE orange color

What makes this plant so aggressive? LIBRARY • High reproductive rate - 95% of seeds germinate • Seeds germinate and establish in low light conditions • Seeds persist in soil for many years • Plants grow in full sun to heavy shade conditions • Plants spread by root suckers, particularly if cut • Rapid growth rate • Vine forms large colonies

Why is this plant so damaging to native plant communities? MAIN STREET Asiatic Bittersweet overtakes and strangles desirable native plants. It forms a dense canopy that prevents the growth of other plant species beneath it.

Factors that limit species growth:

MYSTIC VALLEY PARKWAY Higher growth rate with higher light levels

Management strategies: • Cut stems and apply herbicide to cut ends. Triclopyramine LINCOLN SCHOOL (Brush-B-Gone) can be applied by paint brush to stem MAIN STREET immediately after cutting. • Foliar sprays used on large masses. Sprays are less likely to effect surrounding vegetation in October and November when most other plants are dormant. • Vines can be cut and roots completely removed or sprouts repeatedly cut. Cutting without herbicide application can increase plant spread by encouraging new sprouts. Plants should be cut every two weeks. • Continuous monitoring and removal of new plants.

Asiatic Bittersweet Celastrus orbiculata

Invasive Plant Inventory 21st Century Planting Design and Management Plan Sara Bourque, MLA candidate, Andrew Hovey, Bachelors candidate Mill and Judkins Ponds, Winchester Town Center Juli Riemenschneider RLA, ASLA, Catherine Melina RLA, ASLA,

Partially funded by an Educational Development Grant from the Boston Architectural College 2010-2011 April 2011 Multiflora Rose, Rosa multiflora

Species characteristics: • Woody shrub with arching stems • Size: 10-15 feet wide and tall • Flowers: each flower is 1 inch wide and has five white petals with many yellow anthers, blooms in May to June. • Leaves: alternate odd-pinnately compound, 5 to 11 leaflets, each 1-3 inches long. Margins are serrated. • Fruit: rose hips ¼ to ½” diameter, green ripening to glossy red. WINCHESTER HIGH • Stems: arching stems with thorns SCHOOL What makes this plant so aggressive? • Each plant can produce a million seeds per year. Birds distribute seeds. • 90% of the seeds are viable, and can remain so for 20 N years. • Arching branches that reach the ground can root. • Fast growth rate. It can grow 1 to 2 feet per week.

SHORE ROAD • Thorny branches and dense growth make it difficult to

SKILLINGS ROAD remove. 0 50 100 200 Why is this plant so damaging to native plant communities? It forms impenetrable thickets that exclude native species. It in- vades disturbed sites

Factors that limit species growth: There is a multiflora rose seed chalid that infests 95% of seeds in Asia. This and several other biological control methods are being studied. Plants grow slowly for the first 1 or 2 years and expand GRIFFIN PHOTOGRAPHY rapidly after that. MUSEUM Management strategies • Repeated cutting can slow spread but will not eliminate JENKS CENTER it. • Mowing 3 to 6 times per year around the perimeter of a stand will control expansion. • Herbicide application of triclopyr (Brush-B-Gone) in spring before and during flowering. • Application of glyphosate (Rodeo) after flowering until early fall. Cut stump applications work but are difficult to do because of the dense thorny branches. • Follow up monitoring and removal will be necessary do to eliminate seeds remaining in soil.

POLICE STATION

FIRE STATION

MOUNT VERNON STREET Species characteristics: TOWN HALL • Tall perennial grass • Size: up to 15’ tall • Flowers: bushy panicles in July and August, purple or golden in color

CONVERSE PLACE • Leaves: elongate leaves 1- 1 ½” wide. • Fruit: produces thousands of seeds annually, however viability is low • Roots: dense network of roots and rhizomes, 80% of the LIBRARY plants biomass is below ground

What makes this plant so aggressive? • Spreads by rhizomes that can grow 10 feet in one year. • Rapid growth rate, shades out other vegetation • Fragments of rhizomes in transported soil or that wash down stream can grow into new plants • New plants can grow from seeds.

MAIN STREET Why is this plant so damaging to native plant communities? Once established it overtakes native species, can change hydrolo- gy in marsh areas, and alters wildlife habitat. It becomes a quickly becomes a monoculture.

MYSTIC VALLEY PARKWAY Factors that limit species growth: It usually grows in tidal, non tidal brackish and fresh water marsh- es, on the shores of lakes and rivers and along roadsides. Water

LINCOLN levels of 2” or more prevents seed germination. SCHOOL MAIN STREET Management strategies • Cut at the end of July, leaving less than 6”. • After cutting, cover with black plastic anchored with sand bags or rocks. Remove plastic the following spring and pull or cut any shoots. Only works where sun will heat plastic. • Combination of cutting plants in midsummer and applying glyphosate (Rodeo) when regrowth reaches 2-3 feet. Two to three weeks after herbicide application cut stalks to stimu late emergence of other plants.

Common Reed, Phragmites australis

Partially funded by an Educational Development Grant from the Boston Architectural College 2010-2011 April 2011 Japanese Knotweed, Polygonum cuspidatum

Species characteristics: Species characteristics: • Herbaceous perennial • Size: large clumps to10 feet tall • Flowers: small greenish white in branched sprays, bloom in August & September • Leaves: 6” long by 4” wide, broadly oval to triangular with a pointed tip • Fruit: small winged fruit containing very small black seeds WINCHESTER HIGH SCHOOL What makes this plant so aggressive? • Reproduces by seed • Reproduces by rhizomes that can spread 15-24 feet. • Early season emergence and fast growth rate shade out other plants • Rhizome fragments in transported soil or that wash down N stream can sprout and form new colonies. • Can survive floods and is able to rapidly recolonize disturbed areas.

SHORE ROAD

SKILLINGS ROAD 0 50 100 200 Why is this plant so damaging to native plant communities? It displaces all other vegetation. Once established it is almost im- possible to remove. Any remaining rhizome can sprout into a new plant.

Factors that limit species growth: These plants rarely invade undisturbed forest. They have high light requirements.

GRIFFIN Management strategies: PHOTOGRAPHY MUSEUM • Minimum of three cuttings per year, to off set growth, possibly combined with herbicide application. Multi year cuttings required. When plants are gone, revegetate area with plants JENKS that will provide dense shade at ground level. CENTER • Prevent establishment of new stands, monitor and eradicate new plants. • Glyphosate (Rodeo) application when leaves are translocating to rhizomes, late summer, early fall. Repeated applications necessary. • Cut stand in late June, allow to regrow, after August 1st spray with glyphosate (Rodeo).

POLICE STATION

FIRE STATION Species characteristics: • Deciduous large shrub or small tree • Size: Common 6-18’; Glossy 20’ MOUNT VERNON STREET • Flowers: dense clusters of 2-6 yellow-green 4 petaled TOWN HALL flowers, near the bases of the leaf stalks. Male and female of separate plants, blooms in spring. • Leaves: Common has broadly oval, rounded with a pointed tip and toothed margins, stay green into fall. Glossy CONVERSE PLACE Buckthorn has smooth leaf edges and the undersides of the leaves are hairy. • Fruit: Small black seeds

LIBRARY • Twig: Common buckthorn has a spine at the twig tips, Glossy Buckthorn does not.

What makes this plant so aggressive? • Plants leaf out early • Rapid growth rate. Can produce seeds on current season’s growth. • Seed production, dispersal and germination are effective. • Fruit can float (6 days for Common, 19 days fro Glossy) MAIN STREET making fall flooding a vehicle to distribute seeds. • Forms large thickets.

Why is this plant so damaging to native plant communities? It forms large thickets that create dense and continuous shade. This prevents other plants from growing. MYSTIC VALLEY PARKWAY Factors that limit species growth: Low light can limit establishment. Seeds are more successful in LINCOLN disturbed sites. SCHOOL MAIN STREET Management strategies • Repeated cutting reduces vigor. • Mowing prevents seedling establishment. • Hand pulling newly established seedlings. • Under planting with shade trees that grow to shade out buckthorn. • Girdling and cutting in combination with glyphosate (Rodeo) application.

Common Buckthorn, Rhamnus cathartica Glossy Buckthorn, Rhamnus fragula

Partially funded by an Educational Development Grant from the Boston Architectural College 2010-2011 April 2011 Other Invasive Species

WINCHESTER HIGH SCHOOL

SHORE ROAD

SKILLINGS ROAD 0 50 100 200

Loosestrife, Lythrum salicaria

GRIFFIN PHOTOGRAPHY MUSEUM

JENKS CENTER

POLICE STATION

FIRE Bittersweet nightshade, STATION Solanum dulcamara

MOUNT VERNON STREET

TOWN HALL

CONVERSE PLACE

LIBRARY

MAIN STREET

MYSTIC VALLEY PARKWAY Mulberry, Morus species

LINCOLN SCHOOL MAIN STREET

Partially funded by an Educational Development Grant from the Boston Architectural College 2010-2011 April 2011 Management Plan Strategies: Summary Map

• Eradicate small stands of Phragmites, Japanese Knotweed, Loosestrife to prevent spread (urgent). • Preserve existing trees by removing the WINCHESTER Bittersweet vine that is strangling them HIGH SCHOOL (urgent). • Minimize disruption of plant cover on banks: disturbed soils are condusive to the spread of invasive plants. • Revegetate areas where invasives are N removed. Where possible provide dense

shade at ground level: it limits the growth of SHORE ROAD

some invasive plants. SKILLINGS ROAD 0 50 100 200 • Remove buckthorn, especially in areas where it is out competeing native shrubs. • Remove bittersweet and buckthorn and revegetate with native plants (removal to include continual monitoring and additional removal). • Identify areas where views should be retained GRIFFIN and prioritize removals and revegetation in PHOTOGRAPHY MUSEUM these areas.

JENKS LEGEND CENTER

Tree of Heaven, Ailanthus altissima

Asiatic Bittersweet Celastrus orbiculata

Loosestrife, Lythrum salicaria

Mulberry, Morus species

Bittersweet nightshade, Solanum dulcamara POLICE STATION

Common Reed, Phragmites australis FIRE STATION

Japanese Knotweed, Polygonum cuspidatum

MOUNT VERNON STREET

Common Buckthorn, Rhamnus cathartica TOWN HALL Glossy Buckthorn, Rhamnus fragula

Multiflora Rose, Rosa multiflora CONVERSE PLACE

LIBRARY

MAIN STREET

MYSTIC VALLEY PARKWAY

LINCOLN SCHOOL MAIN STREET

Partially funded by an Educational Development Grant from the Boston Architectural College 2010-2011 April 2011