University of Maryland Extension

FAQs - Lawns - Management Practices - Fall

lawn in the fall

Lawns-Getting StartedLawns-Overseeding & Renovation
Lawns-Management PracticesLawns-Weed Management

      Back to FAQ's

More lawn information

Can you explain to me what the three numbers on every bag of fertilizer mean?

When exactly is the best time to fertilize my lawn? I have heard both the spring or the fall but I want to do the right thing.

My county is urging homeowners to leave grass cuttings on the lawn. I thought it was better to bag them. Similarly, I heard a radio "expert" recommend that leaves should be "mulched" and left on the lawn. What are your recommendations?

My soil test indicates that I have to lime my lawn.  It tells me the amount to apply but not the type of lime. Is there any difference between pelletized lime, hydrated lime, and agricultural lime being sold at the stores? Also when is the best time to apply it?

I was wondering if it really is necessary to fertilize my lawn every year? I really prefer not to use any pesticides.

Can you explain to me what the three numbers on every bag of fertilizer mean?

What you are referring to is sometimes called the guaranteed analysis or nutrient guarantee. The three numbers are separated by hyphens and represent the percent by weight of nitrogen (N), phosphorus (P) and potassium (K). Nitrogen promotes plant growth and color, phosphorus helps with root development and potassium contributes to the overall health of plants helping turf to withstand stresses such as drought or disease. Most Maryland soils have sufficient phosphorus. Soil testing will determine if applying phosphorus is necessary and should only be applied if a soil test shows that your soil is in the low to medium range.
      
When exactly is the best time to fertilize my lawn? I have heard both the spring or the fall but I want to do the right thing.    

The type of grass that you have determines the best time to (PDF) 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. They go dormant in the fall and fertilizer applied then would run-off into the Bay.

My county is urging homeowners to leave grass cuttings on the lawn. I thought it was better to bag them. Similarly, I heard a radio "expert" recommend that leaves should be "mulched" and left on the lawn. What are your recommendations?

Grasscycling or leaving grass clippings on your lawn has many benefits including returning nutrients to the soil, contributing about 25% of the total nitrogen needed for a healthy lawn. Perhaps reducing your fertilizer applications to one per year.  It saves time and energy by eliminating the need to bag or rake and reduces the amount of lawn clippings in the landfill.

A thin layer of tree leaves can be mulched by running them over with a lawn mower and left on the lawn to decompose. You will have to rake the leaves or spread them out if they are thicker than about ½”. Excess mulched leaves can be added to a compost pile or used as mulch in a vegetable or ornamental bed.

My soil test indicates that I have to lime my lawn. It tells me the amount to apply but not the type of lime. Is there any difference between pelletized lime, hydrated lime, and agricultural lime being sold at the stores? Also when is the best time to apply it?

You are correct; there are different types of lime available to homeowners to apply to their soil.  Hydrated lime is produced by adding water to burnt lime.  It changes the pH faster, but only 75% of the recommend amount should be applied to your lawn.  Agricultural lime and pelletized lime are very similar and are interchangeable; they should be applied according to your soil test report. Pelletized lime is easier to apply.  Burnt or ‘quick lime’ should not be used because it can burn plant roots. Lime can be applied to your lawn anytime. However, the fall is a particularly good time because the freezing and thawing of the soil helps to work it into the soil.

I was wondering if it really is necessary to fertilize my lawn every year? I really prefer not to use any pesticides.

Fertilizing lawns at least once a year is important to keep the turf healthy. Healthy turf helps to slow down and filter storm water before it reaches storm drains. A blanket of grass also helps to prevent soil erosion better than a thin lawn where the soil is exposed. Apply fertilizer in the fall to help promote a deep root system. Lawn fertilizers available in stores now will have zero phosphorus and will have to comply with (PDF) The Fertilizer Use Act of 2011. Also, fertilizers are not pesticides. They are safe to handle and are not harmful to you or the environment if used carefully and correctly.

Please send us a question at Ask the Experts if you have a lawn question you would like answered. Digitial photos can be attached to your question.

Spring Summer

Back to Top

Maintained by the IET Department of the College of Agriculture and Natural Resources. © 2017. Web Accessibility