To choose the best winter fertilizer, customers should purchase a plant food mixture which contains high amounts of nitrogen and slightly elevated amounts of potassium. These two chemicals encourage vibrant leaf growth and strong root structures respectively. Slow release fertilizers are frequently applied in the late fall months of the year to prepare lawns and gardens for the low, cold temperatures experienced during winter. Some manufacturers of gardening supplies prepare a fertilizer mixture that is labeled specifically for application prior to winter and contain similar amounts of these essential nutrients.
A winter fertilizer applied early in the fall when temperatures are still warm a majority of the time should contain a high amount of nitrogen. This chemical ingredient is necessary for healthy leaf growth and can be applied to both lawns and flower gardens, which may continue to grow for several more weeks as the season grows cooler before becoming dormant. Consumers can determine how much nitrogen is contained in a bag of fertilizer by reading the first number in the chemical ratio listed on the label. This ratio identifies the amounts of nitrogen, phosphorus, and potassium used in the mixture respectively. Most types of winter fertilizer contain low or no amounts of phosphorus in the mixture.
The cooler weeks of fall require a winter fertilizer that is higher in potassium. This chemical establishes a strong and extensive root network, and is essential when laying seed for a new lawn. Fall is the best time of the year to seed grass because germination can occur over a long period of time, and roots can burrow deep into the ground to access and store much needed ground water and nutrients. Providing a new lawn with potassium also improves the cold hardiness of the grass. The fertilizer should be applied as plants slow in their growth rates, but before the ground has frozen.
Slow release feeding products are common in use as a winter fertilizer. These chemicals are designed to break down over a long period of time instead of feeding plants and lawns immediately. Breakdown of this type of plant food typically occurs through the work of microbes in the soil, and root systems are provided with nitrogen and potassium in small doses throughout the winter. Organic fertilizers also fall into this category as a slow release product and may be applied while temperatures continue to remain relatively warm during daylight hours.