Back to Info Sheets	Maintenance of Your Established Lawn   Spring Clean-Up Remove dead grass and debris from the lawn by raking. If a lot of road salt has been dumped on the lawn, water it thoroughly to help leach the salt away from the grass roots. Established turf will benefit from aerating to get oxygen and water down to the root zone. An early spring application of limestone will help sweeten acidic soils. A general rate of application is 50 kg/100 m2 (100 lbs/1,000 ft2). Half may be applied in spring and half in the fall. Test soil every three years to determine lime requirements. Apply a slow-release lawn fertilizer (Parkwood 21-6-12) at the recommended rate by mid to late May. Use a rotary or drop spreader when the grass is reasonably dry at the recommended rate. It's a good practice to mow a little high in spring to encourage deep root growth and smother weeds.   Mowers set to two and a half inches will provide a well-groomed cover and allow for optimum root development.   Summer Treatment Late June to early July, this is time to give a second fertilization with a high nitrogen fertilizer such as Parkwood 21-6-12.  Do not fertilize if the lawn is water stressed or if the temperatures are above 25 oC  !!! If there is a shortage of rainfall, give the lawn a deep watering weekly. Mow frequently with a sharp mower set to cut high, 2.5" - 3" . Delay use of weed killers until early fall (Aug. - Sept.), or when temperatures are between 15 and 20 oC for best  results. Watch for evidence of insect and disease activity. The most prevalent pest in lawns are Chinch bugs, Sod Cutworm, and European Marsh Crane Flies.  Time application of pesticides for best results before too much damage has been done.  Check out The Backyard Bug Brigade booklet to find out more on these pests.   Fall Fall is a good time to apply lime to your lawn. Half may be applied in fall and half in spring. Determine limestone requirements via a soil test, or use a general rate of  50 kg/100 m2 (100 lbs/1,000 ft2).  Half this rate if you are making an application in the spring and the fall. Fall is the time to apply fall fertilizer with a lower nitrogen number but higher phosphorus and potash  numbers (ie. 6-8-14).   This will strengthen the roots and improve disease resistance of the grass.   Terminology Aerating: using a manual or mechanical device to remove small cores of soil which relieves soil compaction and allows for better gas exchange and deeper water / fertilizer penetration into the soil. Topdressing: very early in the spring you may apply a very thin layer of clay ,peat, and sand over the lawn to help decompose organic mater and enrich the soil. Slow Release Fertilizer: fertilizer that has been designed to release its nutrients to the grass slowly over the summer. vol. 97 no. 1
© Murray's Garden and Horticultural Services Last updated: March 2 2008