The Dangers of Invasive Plants

1
The Dangers of Invasive Plants

• Why We Should Be Careful In Our Selection
• By Mark Klym

2
What Do We Mean By Invasive

• Biologists refer to an invasive plant as one
  that, when planted in your garden, may escape
  cultivation, and, when in the wild, has a
  tendency to establish monocultures by clustering
  and choking out native species.

3
There Are Some General Characteristics of These
Plants

• Highly adaptive
• Usually from regions with similar climates as
  ours
• May or may not produce substances to discourage
  other plant species
• Usually reproduce by multiple means

4
What Is The Danger

• They result in a monoculture which means loss of
  biodiversity
• In regions where there are endangered species,
  this can result in
• Loss of the endangered plant
• Loss of habitat and thus loss of the endangered
  animal

5
What Is The State Doing?

• Some aquatic species have been prohibited in
  Texas for a number of years
• Two sessions ago the legislature authorized the
  Department of Agriculture to establish a list for
  terrestrial plants to prohibit.

6
Some Particularly Troublesome Species Not On The
List
7
Japanese Honeysuckle

• Dangers
• Spreads rapidly choking native vine species
• Common Arguments For
• Its been here forever Im sure it is native
• Wildlife Considerations
• Birds will use it, but native species seem to be
  preferred

8
Japanese Honeysuckle Some Native Alternatives

• Coral honeysuckle is a beautiful vine alternative
  to Japanese honeysuckle
• Coral red flower, evergreen
• Carolina Jessamine is another good alternative
• white flower deciduous
• White Limestone Honeysuckle can also be used
  effectively in the hill country
• White flower, evergreen, late blooming

9
Nandina, Heavenly Bamboo

• Dangers
• Forms dense colonies when in the wild that do not
  allow native plants to germinate
• Common Arguments For
• It is not invasive in my garden
• Wildlife Concerns
• Berries are eaten and seed spread well away from
  the cultivated location

10
Heavenly Bamboo-Some Native Alternatives

• Flame Acanthus
• Native red flowered deciduous
• Agarita
• Native red berried evergreen

11
Chinese Tallow

• Dangers
• Quickly choking out prairie plants on the coastal
  prairie
• Common Arguments For
• Color
• Recommended by AM and state agencies
• Wildlife Concerns
• Atwater's Prairie Chicken
• Prairie sparrows

12
Chinese Tallow-Some Native Alternatives

• Red Oaks
• Brilliant red fall color, deciduous
• Prairie Flameleaf Sumac
• Brilliant red to purple fall color, deciduous,
  bushing

13
Pyracantha

• Dangers
• Form dense thickets with little or no light
  penetration in the wild
• Common Arguments For
• Not invasive in my garden
• Birds love the berries
• Wildlife Concerns
• Berries tend to ferment
• Little value to shelter habitat

14
Pyracantha-Some Native Alternatives

• Yaupon
• Beautiful red berries, evergreen
• Agarita
• Red berries, evergreen, good privacy hedge with
  limited penetration
• Possum haw
• Bright red berries

15
Ligustrum

• Dangers
• Form dense thickets with no light penetration
  choking out even native grasses
• Common Arguments For
• Beautiful hedge is not invasive in my garden
• Wildlife Concerns
• Lack of biodiversity
• No shelter at lower levels

16
Ligustrum-Some Native Alternatives

• Prairie Flameleaf Sumac
• Beautiful fall color but often deciduous
• Evergreen Sumac
• White late summer blossom with evergreen leaves
• Cherry Laurel to the east
• Waxy evergreen leaves but does not like to be
  hedged.

17
Red Tipped Photinia

• Dangers
• Forms dense thickets of woody plants often in
  prairie locations
• Common Arguments For
• Its not invasive in my garden
• Recommended for xeric plantings
• Wildlife Concerns
• Prairies among our most endangered ecosystems

18
Red Tipped Photinia-Some Native Alternatives

• Since the appeal of this plant is the red growth
  tips, Prairie Flameleaf Sumac is probably the
  best native recommendation.

19
Salt Cedar

• Dangers
• Water hog
• Common Arguments For
• Were erosion control
• Wildlife Concerns
• Water loss
• Loss of biodiversity

20
Salt Cedar Some Native Alternatives

• Cottonwoods
• Can be messy
• Soft wood
• Willows
• Form nice loose screen along riparian corridor
• Native oaks
• Slow growing
• Often small plants in these areas

21
Cane NONnative

• Most cane in Texas is currently non-native Arundo
  donax
• Dangers
• Changes physical characteristics of the waterway
• Some Arguments For
• Erosion control
• Wildlife Concerns
• Loss of needed habitat characteristics for fish
  and aquatic species

22
Non-native Cane-Suggested Native Alternative

• Native cane Arundinaria gigantea
• Grows to 20 feet and will get to 1 inch diameter
• Can be planted in swampy sites.

23
What Are The Benefits of Native Plants

• Will use fewer resources
• Water
• Pesticides
• Fertilizers
• Many fertilizers and pesticides are petroleum
  based

24
Some Concerns With Natives

• Hard to find
• Costly to buy
• Often attractive to pests

25
For More Information

• Dangers of Invasive Species
• Texas Wildscapes Gardening For Wildlife
• Native Texas Plants
• Gardening With Prairie Plants

26
For Those Interested In The Texas Wildscapes
Programs

• Best of Texas Backyard Habitats will refuse
  certification to any property with 2 species of
  invasive plants
• Texas Wildscapes will refuse certification to any
  property with 3 species of invasive plant.

27
The Dangers of Invasive Plants

• Why We Should Be Careful In Our Selection
• By Mark Klym