Winter Lawn Overseeding
Since we live in a desert environment, it is important to use our water as efficiently as possible.
Limiting, or forgoing, overseeding is one of many ways to conserve water. There are significant benefits to not overseeding, such as reduced water costs and lower costs associated with preparing and maintaining the winter lawn.
The overseeding process is VERY stressful to Bermuda. Just at the time when it is beginning to store sugars in its roots and rhizomes, all the vegetative parts are cut off stopping that process. It can't manufacture food which weakens the grass making it difficult for it to grow back vigorously in the spring. Its root structure is weakened and it has low tolerance to extreme temperatures. When this process is repeated year after year, the grass may become so weak that it becomes thin or dies out in patches leaving bare spots when the rye dies in late spring.
An option is to allow your Bermuda lawn to rest or go dormant for the winter season. There is nothing wrong with this and in fact, University of Arizona turf specialists agree it’s better for the lawn in most cases. This will save you the costs of installation, maintenance and water. Non overseeded Bermuda will begin greening up as early as February/March. This option allows for other maintenance issues to be resolved and can be used as an opportunity to 'spruce up' landscape areas (see below).
Tip: While Bermuda grass typically goes dormant in the cold months, it is possible to extend the length of its growing season and lush green appearance well into winter. The University of Arizona turf specialists recommend multiple applications of iron (2-4 oz of actual iron per 1000 square feet). Apply the first application about October 1, the next 10 days later and follow up again after another 10 days. Do not apply nitrogen fertilizers. Remember that even dormant Bermuda needs ½ inch of water per month during the winter (from U of A Turf Tips below).
Things to do if you don't overseed
Winter is a great time to work in the yard. If you decide to forgo overseeding this year, you can use the free time for the following garden improvements:
Irrigation schedules. Check for leaks and adjust irrigation schedules for the season. At a minimum, irrigation systems should be adjusted quarterly according to the season.
Pruning. Winter is a good time to prune some landscape shrubs. Instead of regular shearing, consider an annual selective pruning to produce a more natural-looking plant that will bloom to its full potential. Wait until late February or March to prune bougainvillea, lantana, and other frost-damaged plants.
Planting. Fall is the perfect time to plant new areas, replace plants that have died or remove high water use plants. Planting in the fall gives roots a chance to establish in the cool months before the hot summer temperatures hit. There are many low water use plants to choose from. Be sure to select a plant that, at maturity, will fit the planting area. This eliminates the need for future shearing to make it fit the spot.
Weeds. Fall is a great time to get a handle on your weed problem. Application of a pre-emergent herbicide will affect seeds laying dormant in the soil. A post-emergent herbicide can be applied directly to weeds that have sprouted.
Things to do if you do overseed
While it's true that overseeding Bermuda grass lawns with winter rye will provide you with a green, lush lawn for the winter months, it may surprise you to know that more lawns in Chandler are overwatered in the winter months than in summer.
If you are going to overseed, you can save water by irrigating properly. Before you overseed, ask yourself the following questions:
- Will the grass area be used?
Homeowners may decide to forego overseeding the front yard in lieu of overseeding the back yard where family and pets play.
- Is the lawn on a slope?
Sloped areas are difficult to irrigate without causing run off onto sidewalks and streets. Divide your watering cycles over a period of time during the day so water has a chance to soak into the soil. Be on the look out for over watered areas: soils that are constantly soggy, molds or fungi growing on the surface or yellowing of the grass.
- Is the lawn in a narrow strip?
Efficiently watering strips of grass that are less than eight feet wide can prove to be a challenge. Over spray from sprinklers can hit driveways, sidewalks, streets and cars. You may want to consider removing these strips of grass as part of a long-term renovation project.
If you choose to overseed your lawn this fall, using the proper techniques can help save money and water.
Once the rye grass is established and you have mowed it for the first time, it is time to switch your watering schedule. The every day schedule designed to help germinate the seed needs to be changed to irrigating once every 3-10 days. In January your timer should be adjusted again to water every 7-14 days. After a winter rain you can shut off your water for one or two cycles.
Check out the watering guide Landscape Watering by the Numbers for tips on how to water efficiently. An interactive online version is available at www.wateruseitwisely.com. Many water conservation offices also offer free landscape and irrigation workshops in the spring and fall.
City of Chandler
Water Conservation Office