Introduction: Winter Lawn Biology
During the cooler winter months in Pinellas County, St Augustine turf grass lawns are semi-dormant – living and growing but at a slower pace. The soil microbes are still busy too, doing what soil microbes do – enzymatic digestion of organic matter – aka composting – just at a slower pace.
So don’t be fooled into thinking the soil and turfgrass don’t need food and water in the winter – the St Augustine turf and the soil microbes are living, and growing, and need food and water to stay healthy. Without an active and healthy turf and soil microbe population in winter, the St Augustine turfgrass lawn will lag in the spring, losing valuable time during a prime growing season.
5 Things To Do in the Winter for St Augustine Lawns
- Water Your Lawn
- Feed Your Lawn
- Mow Infrequently but as High as the Mower will Go
- Weed Control
- Be Patient
Master these five activities during the winter and you’ll be rewarded with a healthy lawn this spring and well into the summer months.
Water Your Lawn
One persistent myth is that St Augustine needs less irrigation in the winter. This is false. Although semi-dormant St Augustine turf uses less water, our sandy soils dry out at the same rate all year long. Dry soil provides no life-giving water to a lawn - semi-dormant or not.
The turf needs water to survive and soil microbes need moist soil to compost organic matter into plant food. Let the lawn dry out and the lawn and soil microbes die.
The number one determining factor for the health of your St Augustine turf and soil microbes is water – and about 90% of the water your lawn requires will come from irrigation. Therefore, the irrigation system must run, cover the entire lawn, and put out enough water to “fill” the soil. If it doesn’t – then fix and repair until it does.
Feed Your St Augustine Turf Grass Lawn
The main goal of feeding a lawn is not feeding the turf, it is for feeding the soil microbes so that they can compost. Nitrogen, potassium, sulfur, and iron are lacking in our sandy soils and need to be replenished on a regular basis – even in the winter.
I recommend a winter feeding program that focuses on potassium and micronutrients - especially sulfur and iron – but I don’t neglect nitrogen. I limit nitrogen to 0.5 pounds per month per 1000 square feet of the lawn during the winter. One good granular application of a 16-0-8 with a good micronutrient package is sufficient until spring.
Mow Infrequently but as High as the Mower will Go
Winter is not the time to mow low – mowing low does more harm than good in the winter. When you mow low it opens up the canopy, exposing the soil and tender roots and stems to drying sun and cold winter winds. Winter months are a perfect time to skip a few mowings, allowing the canopy to become even higher and reduce wear and tear.
Weed Control is Effective and Safer
Winter is the best time for weed control. Focus on the persistent perennial weeds like Dollar Weed, sedges, and Day Flower. There are other annual weeds that pop up - but they will melt away with the rising temperatures - so focus on the perennials. I suggest Manor and Basagram as good herbicides to use on a St Augustine lawn in the winter months for control of dollar weed, sedges, and dayflower.
Be Patient
This semi-dormant period is natural and very important for the health of the turf – let it do its thing. Pushing the St Augustine turfgrass out of semi-dormancy with excess nitrogen will create a false signal to the turf that spring has sprung and cause havoc with your lawn. I have heard from many homeowners so anxious for a green lawn they overstimulated their winter lawn with nitrogen, saying "My lawn was so pretty - it was the greenest lawn all winter and now it is dead." Don't be tempted to make the lawn green with a parlor trick of high nitrogen fertilizer. Be wise, be patient, and let the grass progress from semi-dormant to spring in a healthy way.
A Word about Professional Lawn Care
Professional lawn care companies, like Barefoot Grass Lawn Care, combine year-round feeding of your lawn with insect and weed control so you don’t have to experiment with different brands and formulations. We know what to do and when to do it – that is what makes lawn spraying such a good service at a good price. If you are overwhelmed by the massive amount of choices for fertilizers, insecticides, and herbicides, you may want to consider hiring a professional.
The end.
