Hort Notes: Massachusetts Prohibited Plants and Non-Invasive Alternatives

September 6, 2016

The 2016 drought in Massachusetts has caused damage to even established landscape plants. As plants need to be replaced this fall and in the coming year, it will be important to help customers understand that some plants in their landscapes are on the Massachusetts Prohibited Plants List and are no longer available for sale at nurseries and garden centers. Plants on the Prohibited Plants List are invasive in Massachusetts and are no longer permitted to be sold or grown in the state. Some of these are common landscape plants, and need to be replaced with non-invasive alternatives. It is important to keep in mind that this includes cultivars, varieties and hybrids of the prohibited plants and plants brought in from other states.

Plants that are determined to be invasive can have the following characteristics:

Few or no natural enemies (insects or diseases)
Grow and mature rapidly
Spread quickly
Can flower and set seed over a long period of time (generally produce a lot of seed)
Thrive in many conditions
Difficult to control
Outside of natural range
Likely to cause harm to the environment or economy
Invade natural habitats
Outcompete other plants for resources (light, water, nutrients, space)

The complete list of Massachusetts Prohibited Plants can be found at: https://www.mass.gov/massachusetts-prohibited-plant-list

There are many great non-invasive alternatives. The following are some of the common landscape plants that are now prohibited along with alternatives.

Prohibited Plant: *Euonymus alatus*		Burning bush or Winged euonymus	Large shrub generally planted for the red fall color. Adaptable to and tolerant of many conditions.
Alternatives: shrubs with red fall color
N	Aronia arbutifolia	chokeberry	6-10’H x 3-6’W; small white flowers in spring, glossy red fruit in late summer-fall
	Fothergilla major	fothergilla	6-10’H x 5-9’W; white bottlebrush flowers in spring; yellow, orange and red fall color
	Fothergilla gardenia	fothergilla	1.5-3’H x 2-4’W; white bottlebrush flowers in spring; yellow, orange and red fall color
	Enkianthus campanulatus	redvein enkianthus	6-10’H x 4-6’W; light yellow-white bell shaped flowers with pink/red stripes; fall color can be red, orange, yellow, or purple
N	Vaccinium corymbosum	highbush blueberry	6-12’H x 8-12’W; white/pink flowers in spring; blueberries; red fall color
N	Vibrunum opulus var. americanum	American cranberrybush viburnum	8-12’H x 8-12’W; white lacecap flowers in spring; red berries in fall; purplish red fall color
N	Itea virginica	Virginia sweetspire	3-5’H x 3-5’W; fragrant white flower racemes in summer; red fall color

Prohibited Plant: *Acer platanoides*		Norway maple	Shade tree with yellow fall color. ‘Crimson King’ is a purple leaf cultivar.
Alternatives: Shade trees or trees with yellow fall color.
N	Acer rubrum	red maple	40-70’H x 30-50’W; red-orange (sometimes yellow) fall color
N	Acer saccharum	sugar maple	40-80H’ x 30-60’W; yellow-orange fall color
N	Quercus rubra	red oak	50-75’H x 50-75’W; brown-red fall color; acorns
	Ginkgo biloba	ginkgo; maidenhair tree	50-80’H x 30-40’W; fan shaped leaves; bright yellow fall color
	Tilia cordata	littleleaf linden	50-70’H x 35-50’W; fragrant flowers attractive to bees

Purple Leaves: Trees that offer purple leaves as alternatives to ‘Crimson King’ Norway maple. Many alternatives are also cultivars
	Cercis canadensis	redbud	‘Forest Pansy’ is a common purple-leaved cultivar
	Fagus sylvatica	European beech	Atropurpurea is the group of purple leaved cultivars; 50-60’H x 30-45’W
	Malus spp.	crabapple	size, leaf color, flowers, and fruit vary by cultivar; important to look for disease resistant cultivars
	Prunus cerasifera	cherry plum	purple leaved cultivars include ‘Krauter Vesuvius’, ‘Newport’, and ‘Thundercloud’; small growing ornamental trees

Prohibited Plant: *Berberis thunbergii*		Japanese barberry	Depending on cultivar can be planted for purple of yellow leaf color, red fall color, red berries in fall, form, or because of thorns.
Purple Leave Alternatives:
	Weigela florida cultivars	weigela	size varies by cultivar; spring blooms; purple leaved cultivars include ‘Wine and Roses’ and ‘Elvera’ (Midnight Wine)
	Physocarpus opulifolius cultivars	ninebark	size varies by cultivar; late spring – early summer blooms; purple leaved cultivars include ‘Summer Wine’ and ‘Diabolo’
Red fall color:
N	Itea virginica	Virginia sweetspire	3-5’H x 3-5’W; fragrant white flower racemes in summer; red fall color
N	Vaccinium corymbosum	highbush blueberry	6-12H’ x 8-12’W; white/pink flowers in spring; blueberries; red fall color
Red berries:
N	Aronia arbutifolia	chokeberry	6-10’H x 3-6’W; small white flowers in spring, red fall color
N	Ilex verticillata	winterberry	3-12’H x 3-12’W; deciduous holly; female plants have red berries in fall-winter
Form:
	Rhus aromatic ‘Grow-Low’	Grow-Low fragrant sumac	1.5-2’H x 6-8’W; spreading shrub with somewhat arching branches; orange-red fall color
	Potentilla fruticosa	cinquefoil	2-4’H x 3-5’W; yellow flowers in summer; bushy mound
	Cotoneaster apiculatus	cranberry cotoneaster	2-3’H x 3-6’W; mounding shrub with arching branches; red berries in late summer – winter; purple-red-bronze fall color
	Deutzia gracilis	slender deutzia	2-5’H x 2-5’W; small fragrant white flowers in spring
Yellow foliage:
	Chamaecyparis pisifera ‘Golden Mop’	Japanese falsecypress	size varies by cultivar; golden yellow foliage; evergreen
	Weigela florida cultivars	weigela	size varies with cultivar; spring blooms; cultivars with yellow leaves include ‘Briant Rubidor’ and variegated ‘French Lace’
	Physocarpus opulifolius cultivars	ninebark	size varies with cultivar; late spring-early summer flowers; yellow leaved cultivar includes ‘Dart’s Gold’
Thorns:
	Rosa ‘Radrazz’ Knockout	Knockout rose	3-4’H x 3-4’W; shrub rose with single red-pink flowers May to frost

Prohibited Plants: *Lonicera maachii , Lonicera x bella , Lonicera morrowi, Lonicera tatarica*		Amur honeysuckle, Bell’s honeysuckle, Morrow’s honeysuckle, Tatarian honeysuckle	Large shrubs with showy white and/or fragrant flowers, fast growth, or red fruit.
Alternatives:
	Deutzia spp.	deutzia	small-medium shrubs with small white fragrant flowers in spring
	Kolkwitzia amabilis	beauty bush	6-10’H x 6-10’W; pink flowers in spring
	Philadephus spp.	mockorange	size depends on species and cultivar; fragrant white flowers in summer
	Spiraea x vanhoutteii	Vanhoutte spirea	5-8’H x 7-10’W; white flowers in spring
N	Amelanchier spp.	serviceberry	large shrub to small trees; white flowers in spring; purple-black berries; red-orange fall color

Prohibited Plant: *Lonicera japonica*		Japanese honeysuckle	Vine with fragrant flowers
Alternatives:
	Lonicera x heckrottii	goldflame honeysuckle	vine; pink/yellow flowers in summer; fragrant; red berries in fall
	Lonicera sempervirens	trumpet honeysuckle	vine; red/orange/yellow flowers in late spring; red berries in fall

Prohibited Plant: *Elaeagnus umbellatus*		Autumn olive	Large shrub with silver leaves. Red fruit in fall. Drought tolerant. White fragrant flowers.
Alternatives:
N	Salix sericea	silky willow	6-12’H; silvery leaves; yellow fall color
N	Cornus sericea	Redosier dogwood/red twig dogwood	6-9’ x 7-10’W; red stems; white flowers in spring, white-blue fruit; good fall color. Also yellow twigged cultivars
N	Myrica pensylvanica	bayberry	5-10’H x 5-10’W; grayish fruits; gray-green leaves
N	Ilex verticillata	winterberry	3-12’H x 3-12’W; deciduous holly; female plants have red berries in fall-winter
N	Aronia arbutifolia	red chokeberry	6-10’H x 3-6’W; small white flowers in spring, red fall color; red berries late summer-fall