Fall is best time to improve a lawn
Fall and winter are times when many people forget about yard care, shutting the door on yard work when they put the lawn mower away for the season. This is understandable ó out of sight, out of mind. However, of all the seasons where proper lawn care is essential for success, fall should be at the top of the list.
Turfís ability to survive winter depends on healthy root systems. Protection of the root from drying requires a bit of water during winter if we are having a dry season. Critically dry soils can lead to a dieback of part of the root system, which will directly limit the ability for top growth of turf during the following growing season. Typically, lawns benefit from watering once every four weeks if we are not getting much rain or snow fall. This keeps the roots hydrated in the soil and prevents them from being pruned by drying out. Keep tabs on how much rain or snow falls at your house ó not across town or in Denver where the TV stations are located ó and water your lawns if you donít get 1 inch of water during the month.
Fertilize for health and color
Kentucky bluegrass, tall fescue and perennial rye are turf types that should be fertilized in the fall. This will enhance their health, increase shoot growth, help suppress weed and disease problems and add a lovely green color through the fall and winter.
Late-season application of fast release nitrogen fertilizer is recommended any time between Oct. 15 and Dec. 15, depending on the condition of the turf. Earlier is better in this time frame, because the grass must be green, the soil must be three weeks away from freezing and free of snow for about six weeks after application.
Dormant or winter season fertilization is different than late season fertilization, and is done with slow- release fertilizer after the turf has lost its green color.
Nitrogen is the most important food to feed the turf ó extra potassium or phosphorus is not as critical. In the late season, the nitrogen in the fertilizer should be from sources such as urea, ammonium sulfate or others that donít need microbes in the soil to release them. Soil microbes slow their activity during cold weather, which may delay release of nitrogen to the plants and make the late season application unsuccessful.
Because fertilizers typically need to be watered in, time the application for when the sprinkler system is still in operation, before it is blown out for the winter. If the lawn canít be watered after fertilizing due to watering restrictions, try to time the application for those brief days when storms are predicted, to take advantage of the natural moisture. In this situation, a combination of fast and slow release fertilizer will give great results.
There is one note of caution for fall fertilization ó if you have sandy soils, donít fertilize after September because the excess may leach into the groundwater.
Aeration opens up soil
Fall aeration is a wonderful practice that will open up the soil for water and reduce compaction, and October is the month to complete this. Core aerators pull plugs of soil from the ground and leave them on top of the lawn to decompose, adding nutrients to the upper top layer of turf. To get the best pull from your plugs, water the lawn 24 hours before you plan to aerate. Pass the aerator over the turf in two to three directions to open up many holes.
Spring Master Gardener
Our Colorado Master Gardener program in Boulder County is currently taking applications for the spring class. If you are interested in helping others garden, the Colorado Master Gardener program is for you. Classes run January through March and will be from 8:30 a.m. to 4 p.m. every Wednesday. Contact the Colorado State University Cooperative Extension Office in Boulder County at 303-678-6238 to receive an application.
For more information on a variety of horticulture topics, visit www.planttalk.org or call (888) 666-3063. Planttalk Colorado is a free service of Colorado State University Cooperative Extension, Denver Botanic Gardens and the Green Industries of Colorado.
Carol OíMeara is with the Colorado State University Cooperative Extension office at the Boulder County Fairgrounds in Longmont. Colorado State University Cooperative Extension, together with Boulder County Parks and Open Space, provides unbiased, research-based information, about consumer and family issues, horticulture, natural resources, agriculture and 4-H youth development. For more information contact Cooperative Extension at the Boulder County Fairgrounds, 9595 Nelson Road, Box B, Longmont, 303-678-6238, or visit www.coopext.colostate. edu/boulder.