· Michael Blair
Cool-season grass does its root work in autumn, which is why the autumn applications matter most and the spring ones matter least — the opposite of what most people assume.
The autumn feeds
An early autumn application supports recovery from summer and the growth that follows overseeding. A late autumn application, after top growth has slowed, goes into root development and carbohydrate storage.
That second one is the single most valuable application of the year for fescue and the one most often skipped.
Spring
A light spring feed is reasonable, and heavy spring nitrogen produces lush top growth with shallow roots going into a Middle Tennessee summer — exactly the wrong combination.
It also means more mowing for no benefit to the plant.
- Late autumn is the most valuable application
- Early autumn supports overseeding and recovery
- Spring feeding light, not heavy
- No nitrogen on dormant summer fescue
- Soil test rather than guessing at rates
Never in summer
Nitrogen on heat-stressed or dormant fescue pushes growth the plant cannot support and burns it. There is no benefit and real risk.
A dormant lawn in July needs water to keep the crown alive and nothing else.
Test the soil
A soil test gives pH and nutrient levels, and Middle Tennessee soils vary. Applying phosphorus that is already plentiful is wasted and runs off.
Extension services offer inexpensive testing, and it turns a fertiliser programme from guesswork into a plan.