Differentiate between cool-season and warm-season weeds, and give an example for Wisconsin.

Differentiate between cool-season and warm-season weeds, and give an example for Wisconsin.

• A. Cool-season weeds germinate in spring and fall; warm-season weeds germinate in late spring or summer; examples: dandelion (cool-season); crabgrass (warm-season)
• B. Cool-season weeds germinate in winter; warm-season weeds germinate in spring
• C. Cool-season weeds do not germinate in Wisconsin; warm-season do
• D. Cool-season weeds are always grasses; warm-season are always broadleaf

Answer: (A)

The main idea here is how soil temperature determines when weeds germinate. Cool-season weeds take advantage of cooler soils and typically germinate in spring and again in fall, while warm-season weeds wait for warmer soils and emerge in late spring through summer. In Wisconsin’s climate, this pattern fits well: you’ll see cool-season weeds like dandelion germinating in spring (and often back in fall), and warm-season weeds like crabgrass appearing in late spring and continuing through summer as the heat arrives. Dandelion is a classic example of a cool-season weed because it thrives and germinates when soils are cool enough in spring, and it can persist and flower across cooler periods. Crabgrass is a classic warm-season weed because it requires warmer soil temperatures to germinate, typically in late spring or early summer when lawns heat up. Other statements aren’t accurate because winter germination isn’t the general rule for Wisconsin weeds, and cool-season weeds aren’t restricted to grasses—many are broadleaf like dandelion. Likewise, warm-season weeds aren’t restricted to broadleaf forms.

The main idea here is how soil temperature determines when weeds germinate. Cool-season weeds take advantage of cooler soils and typically germinate in spring and again in fall, while warm-season weeds wait for warmer soils and emerge in late spring through summer. In Wisconsin’s climate, this pattern fits well: you’ll see cool-season weeds like dandelion germinating in spring (and often back in fall), and warm-season weeds like crabgrass appearing in late spring and continuing through summer as the heat arrives.

Dandelion is a classic example of a cool-season weed because it thrives and germinates when soils are cool enough in spring, and it can persist and flower across cooler periods. Crabgrass is a classic warm-season weed because it requires warmer soil temperatures to germinate, typically in late spring or early summer when lawns heat up.

Other statements aren’t accurate because winter germination isn’t the general rule for Wisconsin weeds, and cool-season weeds aren’t restricted to grasses—many are broadleaf like dandelion. Likewise, warm-season weeds aren’t restricted to broadleaf forms.