Northwood News ♦ June 2014
Fertilizing Your Lawn: New Restrictions in Effect
By Jacquie Bokow
Grass looks good and gives us a place to play outdoors, but it does more than
that. The dense roots formed by grass anchors the soil, preventing
soil erosion; filters pollutants from run-off; and slows excess water down,
allowing it to sink into the ground.
But our lawn care practices can have a negative impact on the health of the
Chesapeake Bay. To combat the negative effect of fertilizer on the Bay, the
Fertilizer Use Act passed in 2011 went into full effect 1 October 2013.
Homeowners and do-it-yourselfers are required to obey fertilizer application
restrictions, observe fertilizer blackout dates, and follow University of Maryland
recommendations when fertilizing lawns. Follow these best management practices
for a healthy lawn and healthy waterways:
- Read and follow all label directions on the fertilizer bag.
- Mow the grass high to shade out weeds.
- Remove no more than one-third of the grass height at each mowing.
- Leave grass clippings on the lawn to provide free fertilizer.
- Sharpen lawnmower blades in the spring.
- Let established lawns go dormant during the hot, dry summer months.
Fertilizer Restrictions for Both Homeowners and Professionals
- Everyone must follow University of Maryland fertilizer recommendations.
- A single fertilizer application may not exceed 0.9 pound total nitrogen per 1,000
square feet and 0.7 pound of soluble nitrogen per 1,000 square feet except when using
- Homeowners should visit extension.umd.edu/hgic for additional guidance; lawn care
professionals should consult the Maryland Professional Lawn Care Management Manual at
for annual nitrogen recommendations.
- Phosphorus may only be applied to lawns when a soil test indicates that it is
needed or when a lawn is being established, patched, or renovated.
- Fertilizer may not be used to de-ice walkways and driveways.
- It is against the law to apply fertilizer to sidewalks, driveways, or other
impervious surfaces, including frozen ground. Any product that lands on these
surfaces must be swept back onto lawns or cleaned up.
- Do not apply fertilizer if heavy rain is predicted.
- Do not apply fertilizer within 15 feet of waterways. This setback is reduced
to 10 feet if a drop spreader, rotary spreader with deflector or targeted spray liquid
is used to apply the fertilizer.
- No lawn fertilizer may be applied between December 1 and March 1. From
November 16 through 1 December, only water-soluble nitrogen (no slow release) may be
applied to lawns at a maximum rate of ½ pound per 1,000 sq.ft.
- Enhanced efficiency controlled-release products may be applied at no more than
2.5 pounds per year, with a maximum monthly release rate of 0.7 pound of nitrogen per
1,000 square feet.
- The type of grass that you have determines the best time of the year to
fertilize. Cool season grasses, like tall fescue and Kentucky bluegrass,
should be fertilized in the fall to help turf recover from summer stress and to
promote a deeper, healthier root system. Warm season grasses like zoysia
and bermudagrass should be fertilized in late-spring through early August.
For Professional Applicators
- Lawn care professionals hired to apply fertilizer to turf must be certified
by the Maryland Department of Agriculture or work under the direct supervision of an
individual who is certified. The law applies to professionals for hire as well
as individuals responsible for turf management at golf courses, public parks,
airports, athletic fields, businesses, cemeteries, and other non-agricultural
- Soil tests must be taken for each new customer and once every three years thereafter.
- Professional applicators may continue to apply natural organic or organic products
containing phosphorus, but, since 1 October 2013, each application may not exceed 0.25
pounds of phosphorus per 1,000 square feet with an annual maximum of 0.5 pounds of
phosphorus per 1,000 sq.ft.
See the University of Maryland Extension Service — online at
extension.umd.edu/hgic/lawns — for further details.