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)

Understanding when weeds germinate helps explain why some weeds show up at certain times and how to manage them. Cool-season weeds begin growth when soils are cooler, so they tend to germinate in spring and again in fall. Warm-season weeds wait for warmer soils and usually germinate in late spring through summer. In Wisconsin yards this pattern is common: cool-season weeds like dandelion sprout early in the growing season and can also re-emerge in fall, while warm-season weeds such as crabgrass start later as soils heat up.

The statement that matches this timing and gives Wisconsin-typical examples is the one that says cool-season weeds germinate in spring and fall, warm-season in late spring or summer, with dandelion as an example of a cool-season weed and crabgrass as a warm-season weed. Dandelion is a classic cool-season, broadleaf weed, and crabgrass is a classic warm-season, grassy weed, illustrating the different temperature windows each group needs.

The other ideas don’t fit Wisconsin reality: some cool-season weeds do germinate in winter, which is not typical for most lawn weeds; cool-season weeds are not restricted to grasses only—they include broadleaf species; and warm-season weeds aren’t limited to late spring or summer in all cases, nor are cool-season weeds restricted to non-weed categories.