Weed Control in Landscape Plantings

Question 1

What is a weed?

Answer 1

A plant growing in an area it wasn’t planted and isn’t desired.

Question 2

What are the five categories of weeds, and how do they differ?

Answer 2

Annuals: Complete life cycle in less than on year and reproduce only by seed. Further divided into Summer and Winter.
Summer Annuals:Germinates in spring and early summer. Mature in fall and die.
Winter Annuals: Germinate in late summer and early fall, die when it gets hot in spring.
Biennials: First year germinate from seed, second year produce seed and die
Perennials: reproduce by vegetative structures; Stolons, rhizomes, tubers, fleshy tap roots and bulbs.

Question 3

What are some cultural/management practices for controlling or preventing weeds?

Answer 3

First step is follow practices to promote vigorous growth and development of intentional plantings.
Adapted Turfgrass species
Fertility management. Use Soil tests to keep soil viable for intended plants.
Cultivation:
Irrigation
Insect and Disease Control

Question 4

What is the difference between a selective and non-selective herbicide?

Answer 4

Selective: Controls one species without affecting another
Non-Selective: no regard to species, best used as spot treatment.

Question 5

What is the difference between a preemergence herbicide and postemergence herbicide?

Answer 5

Preemergence stops plants before they germinate and post is after.

Question 6

Herbicide formulation mayb e listed as S, SL, SP, EC, WP, AS or DG. What do these symbols mean?

Answer 6

S/SL: Water Soluble liquid, completely disolve when mixed with water.
SP: Water Soluble Powders.
EC: Emulsifiable concentrates. Oily liquids that form emulsions
WP: Wettable powders Finely ground solids with a dry diluent (clay) plus herbicide
AS: Aqueous Suspension, Suspend in water, but don’t dissolve
DG: Dispersable granules.

Question 7

What is a spray adjuvent, and how is it used?

Answer 7

spray additive that enhances performance of a herbicide.

Question 8

Convert from rate per acre to rate per 1,000 SF

Answer 8

Divide rate per acre by 43.56

Question 9

How would one calibrate a drop spreader?

Answer 9

Place empty bottles at intervals based on spread and measure what is in each.

Question 10

When is the best time of year to apply preemergence herbicides in your area?

Answer 10

This really depends on the weeds you are targeting, but typically before spring growth occors.

Question 11

What is Contact herbicide

Answer 11

Effects only the green plant tissue contacted by the spray. Does not move through the vascular system of plants.