Why your state's lawn calendar differs from the next state's
State lawn calendars differ by grass, by region within a state and by what triggers a task, with examples from Georgia, Texas and Pennsylvania.
By LawnYear editorial team · Published · Updated Windows are read from the extension publications listed under Sources; the dates are approximate.
Approximate dates for your state. Check with your local cooperative extension office before you act.
Read two state calendars next to each other and the dates rarely match. The sources do not give one explanation, but the pages show three kinds of difference.
The first is the grass. A Virginia calendar covers cool-season grasses and puts the preferred seeding and feeding in late summer and fall. A South Carolina calendar covers warm-season grasses and says to apply no nitrogen from September to December. Two state calendars can both be right and still be months apart because they describe different grasses.
The second is the region inside a state. NC State's tall fescue calendar gives August 15 to September 1 for the western region and September 1 to October 1 for the Piedmont and coastal plain. Penn State gives three crabgrass preventer windows: March 15 to April 15 in the southeast, April 1 to May 1 in other areas and April 15 to May 15 in the northern tier and high-altitude counties. Clemson puts preemergent herbicide in mid-February in coastal and central South Carolina and mid-March in the piedmont and mountains. The Texas bermudagrass text says crabgrass germinates around mid-February in South Texas, early March in North and Central Texas and mid-March in the Panhandle. Georgia notes that location can shift its schedule. Ohio's calendar is written for northeastern Ohio and fits the rest of the state only approximately.
The third is what triggers a task. Some sources use dates. Others use conditions on the lawn or the soil. Georgia says not to feed warm-season grasses in spring until the soil at 4 in is constantly 65 F and rising. Texas ties the St. Augustinegrass preemergent windows to soil at about 55 F for 4 to 5 consecutive days in spring and about 70 F for 5 consecutive days in fall, and says the first feeding waits until the lawn has been mowed at least twice (St. Augustinegrass) or 2 to 3 times (bermudagrass). Clemson puts the first feeding in early May after the lawn fully greens up.
Even the shape of the answer differs. Virginia's chart ranks seasons as preferred and second best. Georgia rates each month as best, possible or marginal. Ohio's calendar gives dates. When this site turns these into windows it uses the best or preferred months, and says in each note when it read a date off a chart or interpreted a season word.
Age differs too. The Ohio calendar used here was revised in 2007, the Clemson programs in 2018 and 2024, and the Virginia calendar in 2025. A newer Ohio State article gives a different mowing height from the 2007 calendar, which shows that even one university's guidance changes.
That is why every page on this site shows approximate dates for a whole state.
How we read the sources: where a post sets states or grasses side by side, the comparison is ours, made by reading the extension pages next to each other. Every number comes from the page named.