Grass needs routine care to remain healthy, compete with weeds, and recuperate from drought, disease, or insect damage.
Maryland’s Lawn Fertilizer Law authorizes the Maryland Department of Agriculture’s Nutrient Management Program to regulate the use of fertilizer on turf not used for agricultural purposes. The following lawn care practices take this law into consideration.
Late Summer to Fall (mid-August through mid-September)
Perform a soil test if you are planning a lawn renovation project. Otherwise, soil testing every 3-4 years is sufficient. Apply nitrogen based on University of Maryland Extension (UME) fertilizer recommendations only.
If soil test results indicate a low pH (6.0 or below) apply lime according to the lab's recommendation. Fall application is best because of winter snow and rain, combined with the freezing and thawing of soil, help to work the lime into the soil. It is not necessary to lime on a yearly basis.
Apply lawn fertilizer according to University of Maryland Extension (UME) fertilizer recommendations.
Core aerate and overseed if needed.
Plant a lawn alternative in areas where grass does not grow well such as heavy shade or sunny slopes.
Late Fall
Rake and remove fallen leaves or use a mulching mower to chop the leaves up and let them decompose on your lawn. Bagged leaves can be composted or used in ornamental or vegetable beds as a winter mulch.
Mow your lawn 1/2 - 1 inch shorter than the usual height to discourage matted grass and snow mold.
Do not apply lawn fertilizer between November 15th and March 1st according to Maryland’s Lawn Fertilizer Law.
Winter
Avoid foot traffic on frozen turf, as injury to the crowns may occur.
Spring
Apply crabgrass preemergent herbicide if you experienced significant crabgrass or Japanese stiltgrass in your lawn last summer. Crabgrass seeds germinate when soil temperatures average 55° F. for seven days to ten days. Preemergents for crabgrass should be applied mid-March through mid-April depending on where you are located in the state. Japanese stiltgrass germinates earlier than crabgrass so to manage it a preemergent needs to be applied a couple of weeks earlier than for crabgrass prevention.
Look for preemergent herbicide products that do not contain fertilizer. If you use a “weed and feed”, the fertilizer in the product needs to be included in the total amount of nitrogen that you apply to your lawn for the year.
A preemergent herbicide cannot be applied if you plan on reseeding in the spring.
Reseed bare spots in March. Major lawn renovation projects should be postponed until late summer or early fall.
A spring application of fertilizer should not be necessary if your lawn was fertilized in the fall.
Handpull broadleaf or grassy weeds.
Summer
Established tall fescue lawns do not need to be irrigated. They will go dormant during the hot, dry weather and green up again when cooler temperatures arrive and rainfall increases.
Raise mower height 1/2 - 1 inch during periods of hot, dry weather. Do not mow lawns that are not growing.
Leave grassclippings to naturally decompose on your lawn. This will not create a thatch build-up or cause disease but will add organic matter and contribute to your lawn’s nitrogen requirement.
Never fertilize turfgrass during the summer. Wait until September.
Inspect your lawn at the end of summer to evaluate if lawn renovation or overseeding is needed.
By Debra Ricigliano, MD Certified Professional Horticulturist, University of Maryland Extension Home and Garden Information Center (HGIC), 2019. Reviewed and edited by Jon Traunfeld, HGIC Director. Based on HGIC publication HG 112 Turfgrass Maintenance Calendars for Maryland Lawns.