Thickening an Established Kentucky Bluegrass Lawn in Detroit

Core Aeration + Overseeding

Rent a core aerator (early fall preferred) and run over the entire lawn. Immediately spread a perennial ryegrass‑dominant seed blend (matches dark‑green KBG color) at a heavy rate. Rake lightly, roll, keep seedbed moist (daily light watering) until established (3–4 weeks), then transition to deep weekly watering.

Fertilization Schedule

• Late May: 1 lb N/1000 sq ft
• Early September: 1 lb N/1000 sq ft
• Early November: 1 lb N/1000 sq ft (after top growth stops—feeds roots)

Avoid early spring and summer applications. Use a 3‑1‑2 or 4‑1‑2 ratio fertilizer with slow‑release nitrogen.

Mowing and Watering

• Mow frequently at 2.5–3.5 in., never removing >1/3 blade.
• Water deeply (1 inch) once per week; during seed establishment, water lightly 2× daily.
• Rake leaves promptly in fall.

Bare Spot Repair

Rough up soil, mix in bagged garden soil or compost, seed, firm, keep moist.

Topdressing Note

Compost topdressing (½ inch) can help but is secondary to aeration and overseeding.