Weeds Will Be With Us – So,
we need to develop weed
management plans.
The First Step: Weed ID –
Its more than a name
How do you correctly identify a weed?
Compare to a photo
Remember weeds can appear different
due to site conditions
Easiest to do when plant is flowering
Keys to Identification
Send a sample to the University
Extension Weed Scientists
Landscape Weed Control – JC Neal, NCSU
Identification Resources
For Piedmont and Coastal Plains
Identifying Seedling and Mature Weeds in
the Southeastern US
Weeds of Southern Turfgrass
Mountains
Weeds of the Northeast
Weeds of Southern Turfgrass
How to order:
Weeds of Southern
Turfgrass
Publication Distributions Center
IFAS Building 664
P. O. Box 110011
University of Florida
Gainesville, FL 32611
(352-392-1764)
On-line: Turffiles
http://www.turffiles.ncsu.edu/turfid/itemselector.aspx
Landscape Weed Control – JC Neal, NCSU
How to order:
PS: I think Clemson has some too)
Landscape Weed Control – JC Neal, NCSU
How to send a sample for ID
Fresh samples: moisten sample; wrap in
DRY paper towel; put in a zip-lock bag and
mail on Monday or Tuesday to the
appropriate specialist
If you cannot send it right away (or if you
get the sample on Thursday or Friday: Lay
flat on between newspaper; press.
Mail the dried, pressed sample to the
appropriate specialist
Weeds of the Northeast
Cornell University Press
P. O. Box 6525
Ithaca, NY 14851-6525
607-277-2211
$29.95 plus $5 shipping
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
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How NOT to send a weed sample
Step 2 -- Develop a weed
management plan
Understand the weed and its life cycle
Weed management options
Optimum time to control the pest
Proper application
Too Dry
Too Wet
Landscape Weed Control – JC Neal, NCSU
Life cycle of an annual weed
Plant
dies
Seed
Plant
sets
seed
Seedling
Landscape Weed Control – JC Neal, NCSU
Life cycle of a winter annual weed
Plant
dies
Summer
Fall
Seed
Plant
sets
seed
Plant
flowers
Seedling
Plant
flowers
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
Life cycle of a summer annual weed
Common
winter annual
weeds
Plant
dies
Spring
Fall
Seed
Plant
sets
seed
Landscape Weed Control – JC Neal, NCSU
Seedling
Plant
flowers
Landscape Weed Control – JC Neal, NCSU
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Common Summer Annual Weeds
Life cycle of a perennial weed
Roots/
rhizomes
spread
Seed
Seedling
J. Derr
Plant
Over-winters
Plant
Flowers
Plant
sets
Seed
New plant
Landscape Weed Control – JC Neal, NCSU
Some common perennial weeds
Landscape Weed Control – JC Neal, NCSU
Perennial Weeds Reproduce
By:
Seeds
Tubers
Bulbs
Rhizomes
Stolons
Landscape Weed Control – JC Neal, NCSU
Types of Perennial Weeds
Simple perennials
Creeping perennials
Rhizomes
Stolons
Creeping roots that produce shoots
Tuberous perennials
Bulbous perennials
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
Simple Perennials
Spread by seed
Tap root or hardy
fibrous root system
Examples: dandelion,
plantain, dogfennel,
pokeweed
Tap root
Landscape Weed Control – JC Neal, NCSU
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Creeping Perennials
Stolon
Reproduce and spread by
Underground stems (rhizomes)
Above-ground stems (stolons)
Creeping fleshy roots that produce
Rhizome
new shoots
Many also reproduce by
seeds or other means.
Tuberous Perennials
Tubers are swollen,
modified stems that are
often resilient to controls,
spread by cultivation, and
may persist in the soil for
years.
Tubers form on rhizomes
Landscape Weed Control – JC Neal, NCSU
Bulbous Perennials
Tubers
Landscape Weed Control – JC Neal, NCSU
Weeds Are Also Classified By:
Persist through the
dormant season as a bulb
Wild garlic and
wild onion produce
bulblets, aerial bulblets,
and seeds
Cotyledons (Seed leaves)
Monocot
(one seed leaf)
Landscape Weed Control – JC Neal, NCSU
Monocots
Dicot
(two seed leaves)
Landscape Weed Control – JC Neal, NCSU
Monocots -- Examples
One seed leaf when
plant emerges
Long narrow leaves
Parallel veins
Grasses
Onions
Garlic
Landscape Weed Control – JC Neal, NCSU
Sedges
Rushes
Lilies
Dayflower
Landscape Weed Control – JC Neal, NCSU
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Grasses
seedhead
Rounded or flattened stems and
nodes
Have fibrous root systems
Some have fibrous roots, rhizomes
or stolons for reproduction
Growing point is below surface
blade
ligule
sheath
Grasses are
identified by:
auricles
midrib
collar
stolon
bud leaf
crown
rhizome
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
Ligules
Vernation or Leaf Bud
Rolled in the bud
Folded in the bud
Absent
Membranous
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
Auricles
Ligules
Absent
Hairy
Membranous
Hairy
Absent
Landscape Weed Control – JC Neal, NCSU
Present
Clasping
Landscape Weed Control – JC Neal, NCSU
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Seed heads
Panicle
Branched spike
Seed heads
Spike
Panicle
Branched spike
Landscape Weed Control – JC Neal, NCSU
Grass-Like Weeds
Sedges: Sedges have triangular “stems”.
Grasses have flat or rounded “stems”.
Annual and perennial species
Most common and difficult to control are
yellow and purple nutsedge
Wild Garlic and wild onion: hollow
leaves have a pungent onion-like or
garlic-like aroma
Wild garlic is the most common
Landscape Weed Control – JC Neal, NCSU
Wild Garlic (Allium vineale)
Bulbous
perennial
„ Strong scent
„ Reproduces by
bulblets, rarely
by seed
„ Emerges in the
winter and dies
back in late
spring or early
summer
Spike
Landscape Weed Control – JC Neal, NCSU
Yellow and Purple
Nutsedges (Cyperus spp.)
Grass-like, but “Sedges
have edges” – triangular
“stems”
Leaves emerge 3-ranked
Spread by rhizomes and
over-winter as tubers
Tubers often introduced in
top soil
Landscape Weed Control – JC Neal, NCSU
Dicots or Broadleaf weeds
„
Two seed leaves (cotyledons)
Leaves have netted veins
Largest group of weeds
Often with bright showy flowers
Exposed growing points
ART FROM 2-2
Aerial bulblets
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
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Unique Characteristics
How to ID Dicots
Look for:
Flowers
Unique Characteristics
Growth Habit
Leaf Orientation, Shape, Etc.
Thorns or spines
Square or winged stems
Compound leaves
Whorled leaves
Milky sap
Landscape Weed Control – JC Neal, NCSU
Growth Habits
Landscape Weed Control – JC Neal, NCSU
Leaf Orientation
J. Neal
J. Neal
Opposite
Whorled
Alternate
Spreading
Upright
Landscape Weed Control – JC Neal, NCSU
Simple Verses Compound Leaves
Rosette
Landscape Weed Control – JC Neal, NCSU
Other Ways to Identify Cont.
Leaf shape
Leaf margin
Toothed,entire,lobed, or deeply cut
Pinnate
Simple
Palmate
Petiole length
Hair on leaves or other parts
Compound
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
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Leaf Shapes, tips & bases
Deeply
lobed
Leaf Margins
Shallow
lobes or
toothed
J. Ditomaso
Entire
Landscape Weed Control – JC Neal, NCSU
Hairs –
present or absent, & where?
Mouseear chickweed -Hairs on stem & leaves
Landscape Weed Control – JC Neal, NCSU
Tell Me What You See?
Common chickweed -Hairs absent
Landscape Weed Control – JC Neal, NCSU
Tell Me What You See?
Landscape Weed Control – JC Neal, NCSU
Tell Me What You See?
Rosette
Broad, nearly
entire leaves
5 veins
Flowers on
spikes
Broadleaf plantain
Landscape Weed Control – JC Neal, NCSU
Landscape Weed Control – JC Neal, NCSU
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Tell Me What You See?
Alternate leaves
Deeply divided
(dissected)
leaves. Twice
lobed.
Landscape Weed Control – JC Neal, NCSU
Assignment – Weed Collection
25 common weeds
Press, dry and mount
Correctly identified
Include required specimen label information
Due Date: October 20th
Landscape Weed Control – JC Neal, NCSU
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