Bermuda grass is commonly used in Phoenix to achieve lush and green summer lawns. As long as it is adequately watered, it is extremely resilient to the desert temperatures. However, Bermuda grass is dormant during the winter, which results in a dead-looking and yellowed lawn. The grass will revitalize around May when temperatures begin to rise. Because of the winter appearance, many landowners in Phoenix invest in overseeding. Overseeding is the process of applying Ryegrass on top of the existing Bermuda grass. Perennial ryegrass is the perfect complement to Bermuda because it grows fast and produces a beautifully dark green and leafy lawn. Initial seeding usually begins the first half of October when the temperatures begin to get cooler. Because of the extreme Phoenix temperatures, ryegrass usually dies in May when temperatures exceed 100 degrees for a consistent period of time, so reseeding will need to be done the following October.
Before overseeding can be done, the lawn needs to be prepared ahead of time. Bermuda grass needs to be mowed to approximately ½ inch high, and all grass clippings should be removed. The lawn is then dethatched; care should be given when doing this. Dethatching is a process that breaks up the ‘matting’ of the Bermuda and allows for better seed-to-soil contact. The combination of low mowing, dethatching, and the removal of the grass clippings exposes the soil for the Ryegrass seeds. In order for Ryegrass to germinate quickly, it must have contact with the soil, and not be competing with other landscape growth. Fertilizer is applied after seeding is finished, and water is key to seed germination. The amount and timing of water is critical and will change once the lawn is established. In the beginning short, frequent, watering will keep the seeds moist and ready to grow. When mowing for the first time, the mower should be set at a higher height to not damage the new grass. Gradually reduce the height, over subsequent weeks, until the desired height is reached. Timing is critical in all phases of overseeding from lawn preparation to seeding to watering and mowing.