Weeds and Weed Removal

1
Weeds and Weed Removal

• Plant Science I

2
What are Weeds?

• A weed is any unwanted plant in an area

3
Specific Weeds

• Some plants are always considered weeds
• Broadleaf plantain
• Buckhorn plantain
• Dandelion
• Crabgrass
• Clover
• Purslane
• Nutsedge

4
Whats so Wrong with Weeds?

• Weeds are plants we DONT want growing next to
  plants we DO want
• Weeds compete for the same nutrients, water, and
  light our plants need to grow
• Weeds are unattractive
• Weeds can attract pests we dont want

5
I have weeds what next?

• Weed removal takes many shapes
• Pre-emergence
• Chemical
• Non-chemical
• Post-emergence
• Chemical
• Non-chemical

6
Pre-Emergence

• Certain herbicides are available to kill weeds
  before they grow (Preen)
• Using clean, sterile soil and mechanics (pots,
  etc.) will help prevent weed growth
• Keeping weeds out of the greenhouse will prevent
  weed seed from getting into plant pots

7
Post-Emergence

• Any number of herbicides exist to control weed
  growth (Round-up)
• Home made sprays such as bleach mixtures
  sometimes work
• Hand-pulling weeds is extremely effective under
  the following two conditions
• The entire weed root is removed
• The weed has not yet gone to seed

8
Questions for Review

• What is a weed?
• Name 5 types of weeds.
• Why dont we want weeds?
• Compare and contrast pre-emergence and
  post-emergence weed control methods.
• Answer questions 7, 9, 15, 16, 19, and 22 in the
  textbook on pages 225-226