Keep your lawn or garden healthy before it goes into a period of winter dormancy with an application of fertilizer in the late fall. This is the time when cool-season grasses recover from summer stresses. And turfgrass can begin to store carbohydrate reserves in the stems, rhizomes, and stolons. These carbohydrate reserves help grass resist winter injury and disease, and they serve as an energy source for growth the following spring.
Late-fall fertilization will also provide:
- Better winter color
- Enhanced spring green-up
- Increased rooting
- Replenished soil in depleted garden beds
When to Fertilize
Plan to put down your fall fertilizer when the grass has stopped growing or has slowed down to the point of not needing to be mowed. If fertilizer is applied too early while grass or garden plants are vigorously growing, it can invite winter injury and snow mold the following spring.
However, don't wait until the ground freezes, and don't apply fertilizer over snow or ice. On the flip side, it is best to fertilize a lawn right before rain. The rainfall will help to water in the fertilizer, allowing it to sink into the soil. Just make sure the rain forecast doesn't call for a heavy downpour, as that can wash away the fertilizer.
Equipment / Tools
- Fertilizer applicator (optional)
Choose the Right Mixture
A complete fertilizer with a high ratio of both nitrogen and potassium is essential for enhanced rooting, cold hardiness, disease resistance, and wear tolerance. An ideal fall fertilizer blend has a nitrogen to phosphorus to potassium (N:P:K) ratio of 24-4-12 with isobutylidene diurea (IBDU).
In this formulation, a small amount of nitrogen is immediately available to the plant. The rest is in slow-release form, allowing it to break down and provide an extended feeding to the grass. Be wary of applying a fertilizer with too much phosphorus (P), as the runoff can damage rivers and streams.
Determine How Much Fertilizer You Need
Nitrogen is the most important nutrient for a fall fertilizer. A recommended dose for lawns is 1 pound of soluble nitrogen for every 1,000 square feet or 1 1/2 to 2 pounds of slow-release nitrogen for every 1,000 square feet. Also check what the label recommends on your chosen fertilizer.
Create a Fertilizing Schedule
It's possible to overfertilize your lawn and garden. Too much fertilizer can cause fertilizer burn (which appears like leaf scorch), impede water uptake by the roots, and lead to excessive but unhealthy growth.
One mid to late summer feeding of a lawn, followed by a light fall feeding, can produce a better lawn than the old recommendation for three or four major feedings for each growing season. In addition, mulching lawn clippings rather than bagging them can be a natural source of nutrients for your lawn, allowing you to reduce fertilizer application.
Flower and vegetable gardens similarly can thrive with fewer fertilizer applications than once believed, especially if they are properly amended with compost and other organic materials. Most gardens do well with one feeding shortly after planting and one as the growing season concludes. However, plants that produce large quantities of vegetables or large, plentiful flowers might need more fertilizer. So always check the specific fertilizer requirements for your plant species.
Nutrient Pollution: A Persistent Threat to Waterways. Environmental Health Perspectives.
Too Much Fertilizer Is Not A Good Thing! North Carolina State University Cooperative Extension.