How to keep St. Augustine, Zoysia, and Bermuda thriving from December through February
If you’ve lived in South Florida long long enough, you already know winter here is not really winter. Our lawns don’t go fully dormant like they do in north or central Florida. Instead, growth slows, soil biology cools slightly, and nutrient demand shifts, but your lawn still actively uses nitrogen, potassium, and certain micronutrients all winter long.
Below is the ideal winter fertilization schedule for South Florida lawns, with month-specific guidance, NPK targets, and product recommendations specifically designed for South Florida lawns.
Winter Growth in South Florida
Mild temperatures mean mild dormancy
From December through February, most lawns here experience daytime temperatures in the 70s, soil temperatures in the upper 60s to low 70s, reduced but not halted photosynthesis, active root metabolism, and continuous micronutrient usage. This means your turf, whether St. Augustine, Zoysia, or Bermuda, still needs consistent nutrition, just in adjusted amounts.
Why winter fertilization matters
When done correctly, winter treatments maintain color without surge growth, strengthen roots before spring, improve stress tolerance during cold fronts, support soil biology as temperatures dip, and reduce early-spring weed pressure.
When done poorly, especially with too much nitrogen, winter fertilization can cause surge growth that is susceptible to fungus, create salt stress, increase chinch bug pressure, or simply waste product the lawn cannot use efficiently.
The Ideal Winter Fertilization Schedule (Month-by-Month)
December: Low-nitrogen, high-potassium stabilization
December is the transition month. Growth slows, but soil temperatures are still warm enough for nutrient uptake.
Recommended NPK Target:
- 0–0.25 lb nitrogen per 1,000 sq ft
- 0.25–0.50 lb potassium per 1,000 sq ft
Potassium boosts stress tolerance during cooler nights, low nitrogen maintains color without pushing blade growth, and this combination supports root stability going into January and February.
Ideal products include a 0-0-25 or 0-0-22 potassium blend, a micronutrient package high in manganese and iron, and an optional small dose of slow-release nitrogen.
January: Micronutrient and soil-health month
January is typically the coldest month in South Florida, and lawns use nitrogen more slowly than at any other point in the year.
Recommended NPK Target:
- 0–0.10 lb nitrogen per 1,000 sq ft
- 0.25 lb potassium per 1,000 sq ft
- Iron, manganese, magnesium
Iron helps maintain color without generating excess growth, manganese supports root function in cooler soils, and potassium helps protect during cold snaps. Avoid moderate or high nitrogen to prevent disease issues.
Ideal products include an iron/manganese blend, 0-0-25 potassium, and humic or fulvic acids to support microbial activity during cooler weeks.
February: Pre-spring nutrition primer
By late February, soil temperatures begin rising and the lawn prepares for the spring growth window.
Recommended NPK Target:
- 0.30–0.50 lb nitrogen per 1,000 sq ft (slow-release preferred)
- 0.25 lb potassium per 1,000 sq ft
- Iron, manganese, magnesium, trace elements
This promotes gentle green-up without causing surge growth. It supports lateral spread, new stolons, and stronger roots heading into March.
Ideal products include slow-release nitrogen (poly-coated or organic), an 18-0-18 style blend, and a micronutrient package.
What Not to Do in the Winter
Avoid high nitrogen
High nitrogen in winter often results in fungus outbreaks, rapid but weak growth, unnecessary thatch accumulation, and increased insect pressure.
Avoid phosphorus unless a soil test calls for it
Most South Florida soils, particularly in Palm Beach and Broward, already contain sufficient phosphorus. Only add P if a soil test indicates a deficiency.
Avoid fertilizing during extended cold spells
If daytime temperatures stay below about 65 degrees for several days, wait until conditions warm back up.
Winter Fertilization by Grass Type
St. Augustine (Floratam, Palmetto, CitraBlue)
St. Augustine has the lowest nitrogen demand of the major warm-season grasses. It responds best to potassium and micronutrients in winter. Avoid more than about 0.25 lb nitrogen at any time before late February.
Zoysia (Empire, Zeon, CitraZoy)
Zoysia is a very efficient nutrient user in cooler periods. Iron is especially helpful for maintaining winter color. Keep nitrogen low until mid-February.
Bermuda (Celebration, Bimini)
Bermuda remains semi-active due to South Florida’s retained soil warmth. It can tolerate slightly more nitrogen in February but still benefits from consistent potassium for stress tolerance.
The Floridist Preferred Winter Schedule (Simple Version)
December:
- 0-0-25 potassium and a micronutrient blend
January:
- Micronutrients only (iron and manganese)
- Optional humic acid
February:
- Slow-release nitrogen (0.3–0.5 lb N per 1,000 sq ft)
- 0-0-25 potassium
- Micronutrients
Should You Fertilize More Often in Winter?
Winter is a maintenance period, not a growth period. More fertilizer does not equal a greener lawn this time of year. The goal is stability, not pushing new growth.
Winter Irrigation Guidance
Granular applications should be watered in with about 0.25–0.50 inches of water. Liquid applications can be applied in the morning; irrigation may or may not be needed depending on the label. Avoid overwatering in January to reduce fungus risk.