Cooperative Extension

Lawns Online! Lesson 3 - December, January & February

Fertilizer

Fertilizer should not be applied during the winter months when the grass is not actively growing.  In fact, applications of fertilizer made when the ground is frozen can lead to serious problems with nutrients actually running off the lawn.  The fertilizations made in the fall will help fescue maintain a reasonably good color throughout most of the winter.  Of course, severe cold for extended periods of time in January and February can cause some temporary "yellowing".  However, when the grass begins to break winter dormancy it will use the food stored from the late November fertilization to green-up quickly.

Crabgrass Prevention

Crabgrass is usually considered a weed in fescue lawns. Because it is an annual (grows from seed each spring, produces seed in the summer, then dies with the first killing frost) it leaves bare soil with no protection over the course of the winter. The fact that it is an annual makes it easier to plan for control. Crabgrass can be prevented by applying a pre-emergent herbicide in early spring. When applied prior to germination, a pre-emergent herbicide sets up a barrier which effectively kills the germinating seeds. The rule of thumb: apply the pre-emergent crabgrass control when the forsythia is in full bloom. The soil temperature that stimulates crabgrass seed germination coincides very well with forsythia blooming. Where crabgrass has been a problem, it is often necessary to make a second application of the pr-emergent 6 to 8 weeks after the first application (consult the label). This ensures full season protection.

Important to control of crabgrass is to be sure the weed you want to control is really crabgrass. Frequently, homeowners mistake common bermudagrass (wiregrass) for crabgrass. Since bermudagrass is a perennial rather than an annual, pre-emergent herbicides give no control at all! Check the illustrations below to help with proper identification.

While spring is not a good time to seed, sometimes it is unavoidable. If you need to seed and control crabgrass there is only one product available for that purpose. Siduron is available in local garden centers for this purpose. It can be applied at the same time fescue seed is planted providing crabgrass control and will not hurt the fescue. Keep in mind, however, that spring seedings come up great, then tend to die out from the heat of summer.

Since we don't recommend fertilization in early spring, use a pre-emergent herbicide that does not contain fertilizer.

Watering

Mother Nature usually takes care of water for us during the winter. With cooler temperatures water loss is not the problem it is during the hot humid days of summer. Also, dormant fescue has less need for water than actively growing fescue. Finally, deciduous trees (those that drop their leaves in fall) are not competing with the roots of grass for moisture.

Mowing

Continue to mow grass as long as it's growing. Fescue grows best when mowed 3 to 4 inches high. During the dormant period (winter) this can be lowered to 2 to 3 inches high. However, it's important to raise the lawn mower again when we get into the warm days of April and early May. Remember, plants produce food through photosynthesis. That means they absorb light through their leaves (blades) which they use to manufacture food for their roots. The longer the blades of grass, the more food they are able to produce. Mowing too low reduces the amount of food grass plants can make.

Weed Control

In Lesson 2 we discussed the value of broadleaf weed control in late fall. Common weeds such as chickweed and henbit germinate in the fall and grow slowly through the winter. Through the first warm days of February they start growing rapidly. Before you know it they are 4 inches tall and starting to bloom. If you missed the fall treatment period (late October/ early November) you can still treat during the winter IF you get two or three days with temperatures above 60 degrees.

clover	henbit	lespedeza

Key Points for Winter

• Keep mowing as long as the grass continues to grow.
• Don't fertilize after the end of November or early December if the grass is not actively growing.
• If you reduce the mowing height on your lawn mower for winter, don't go below 2 inches and be sure to raise it again in the spring.
• If you wish to control crabgrass, use a pre-emergent herbicide when the dogwood is in bloom (usually mid to late March).

Questions? Contact us by e-mail

If you have specific questions about your lawn, email ourExtension staff at edwardssu@chesterfield.gov.

• Go to Lesson 1 - August & September
• Go to Lesson 2 - October & November
• Go to Lesson 3 - December, January & February
• Go to Lesson 4 - March & April
• Go to Lesson 5 - May, June & July
• How to measure your yard