Our gardens are a great place to start identifying and eradicating harmful and invasive weeds. This class covers the most common garden invaders (including pesky weed species) and best practices for making sure they leave, and don’t come back.

1. January 2012
© Independence Gardens LLC
Garden
Invaders
Independence Gardens
Portland, OR
Download the handout that goes
along with this slideshow!
h p://bit.ly/AgInWs
Tuesday, January 31, 2012

2. What We’ll Cover Today
Intro
we are Independence Gardens
• We build raised beds, chicken coops,
terraces, trellises, & other garden
infrastructure
• Help with garden design & planning,
cleanup, prep, and installation
• Teach edible gardening classes
• & make Doo Tees!
Tuesday, January 31, 2012

3. What We’ll Cover Today
Preview
Topics We’ll Cover
Got Questions?
• Top four baddie invaders
Please ask as we go along.
• Weeds: invasive, noxious, or
just annoying?
• Other garden invaders
• Recommended prevention.
control, & disposal methods
• Resources
• Take-home message
Tuesday, January 31, 2012

4. And Some Other Options
Our “favorite” garden invaders
Himalayan blackberry English ivy
Bu er y bush
Field bindweed Why are these “favorites”?
Because we don’t feel particularly con icted
about removing them...
Tuesday, January 31, 2012

5. And Some Otherblackberry
Control for Options
• Manual
removal of
canes
• Manual
removal of
rootballs
• Mow (or
use goats)
to prevent
foliage
regrowth
Tuesday, January 31, 2012

6. And Some Other for ivy
Control Options
• Remove foliage, vines, and
roots manually
• Cut all vines that run up trees at
base of tree
- Ivy owers and fruits on vertical
growth, so focus on ge ing rid
of it
• Use goats to help keep foliage
from growing back
Tuesday, January 31, 2012

7. And Some Other Options
Control for bu er y bush
• Intervene
before it
goes to
seed...
• “One-cut
pruning”
• Remove
stumps
manually
(or get
help...)
Tuesday, January 31, 2012

8. And Some Other bindweed
Control for Options
• Remove vines
• Reproduction
occurs by
rhizome, so
try not to
leave pieces
• Solarize
• Apply thick
sheet mulch
• Monitor (esp.
edges)
Tuesday, January 31, 2012

9. And Some Other Options
Weeds that aren’t so bad
White clover
Trifolium repens
Li le western bi ercress
Cardamine oligosperma
Plantain
Plantago major
Chickweed Red deadne le Dandelion
Stellaria media Lamium purpureum Taraxacum officinale
Tuesday, January 31, 2012

10. Why Compost?difference?
What’s the
• Good weeds a ract bene cial insects, give clues about
our soil quality, add nutrients to our gardens, and feed us
• By de nition, invasive weeds are non-native & were
introduced here; they tend to be aggressive competitors
for space & resources
• Noxious weeds have a negative economic impact and are
regulated by federal & state governments
• We focus on removing invasives and noxious weeds, and
tend not to worry as much about the others...
Tuesday, January 31, 2012

11. Why Compost?
Parallel invaders: Pests
• Similar to weeds, pest
invaders require:
- Positive identi cation
- Familiarity with method
of reproduction/spread
- Properly timed
intervention
- Effective use of
deterrents
- Responsible use of -cides
Tuesday, January 31, 2012

12. Why Compost? “Oopsies”
Parallel invaders:
• Oopsies = plants that have
reproduced without your
permission
• Similar to other weeds,
“oopsies” require you to
- Notice early
- Observe functions/let them
serve those f ’ns if appropriate
(e.g. pollinator a ractors)
- Remove ASAP
Tuesday, January 31, 2012

13. Why An ounce of prevention...
Compost?
• “Being there”
- Observation, then
intervention
• Focusing on
maintaining soil health
and encouraging
desired plants’ growth
• Watering YOUR
plants, not the whole
garden area
Tuesday, January 31, 2012

14. Why Prevention: Raised beds
Compost?
• Effective barrier to
weeds that spread by
rhizome
• Loose soil makes
weeds easy to pull
out
• Still have to monitor
for oopsies and bird-
dropped/wind-
blown seeds
Tuesday, January 31, 2012

15. Why Compost? crops & mulch
Prevention: Cover
• Nature abhors a
vacuum (and bare
soil, too)
• Cover crops are
noninvasive/non-
irritating
competitors
• Mulches smother
weeds/prevent
photosynthesis
Tuesday, January 31, 2012

16. Why Compost? Hoes!
Removal:
• Plants can’t make
food if foliage is
disconnected from
roots
• Use the hoe to cut
the plant just below
the soil surface
• Adjust blade angle
so you don’t have to
bend to use it
Tuesday, January 31, 2012

17. Why Compost?
Removal: Other tools
• Hand pruners
• Loppers
• Saws
• Machetes
• Hori-horis
• Lawnmowers
• Fire: don’t (just) play with
it!
Tuesday, January 31, 2012

18. Why Compost?
Disposal
• Commercial
composting (pu ing it
out in your yard debris
roll-cart) is the best bet
• Non-noxious weeds that
have not gone to seed
can be composted in a
backyard system
• If you do use chemicals,
don’t assume safety
Tuesday, January 31, 2012

19. A note on herbicides
• Please...avoid weed & feed &
other non-speci c products
• Follow IPM hierarchy (chemical
control comes in dead last)
• Look for pre- and post-emergent
control products that are OMRI-
listed, if possible
• ALWAYS read the label and
ALWAYS follow instructions
• Wear your PPE!
Tuesday, January 31, 2012

20. Common pitfalls
• Time constraints
• Lack of consistency
• Discomfort with
eliminating living
things
• Improper technique
• Trying to eliminate
ALL weeds
Tuesday, January 31, 2012

21. Take-home message
• Some weeds are way worse
than others
• Your involvement is key
• Include others in your
garden routine if at all
possible
• Don’t let a problem become
a Problem
• It’s OK to ask for help
Tuesday, January 31, 2012

22. Resources
Do this!
• Oregon noxious weeds lists:
h p://www.oregon.gov/ODA/
PLANT/WEEDS/
statelist2.shtml
• Weed identi cation: h p://
mint.ippc.orst.edu/
weedidenti cation.htm
• Paci c Northwest’s Least
Wanted List:
extension.oregonstate.edu/
catalog/pdf/ec/ec1563.pdf
Not this.
Tuesday, January 31, 2012

23. Got Questions?
Tuesday, January 31, 2012