Calendar · Minneapolis MN · Burlington VT

Perennial Ryegrass care calendar for zone 4

Cold continental winter with a meaningful growing season April–October. Cool-season grasses dominate; buffalo grass viable in the western half (semi-arid). Snow mold is a real concern: last mow of the year should drop the lawn to 2–2.5 inches before the first hard freeze.

Perennial ryegrass germinates in 5–7 days, faster than any other common lawn grass, which is why it is the standard "quick green-up" component of Northern seed blends and the standard winter overseed for warm-season lawns from zone 8 south. It is bunch-type, so it does not self-repair, and it is susceptible to gray leaf spot in humid summers.