Over-Seeding

It’s Over-seeding time again. Over seeding is not always necessary and sometimes not even healthy for lawns. If you don’t have and authority such as an HOA requiring you to think of the pro and cons:

Pro’s-
1) It is aesthetically pleasing
2) Year round recreation area
3) Can improve health of lawn area

Con’s
1) Can harm a already struggling lawn
2) Takes water to grow and keep alive
3) Takes time and/or money to maintenance

Aesthetics is a very big deciding factor in most decisions, why shouldn’t it be for landscape decisions too. As long as it isn’t unhealthy for the lawn go for it. It is rare for over seeding to have much if any effect, positively or negatively, directly on the Bermuda “summer” grass.
If your Bermuda grass is fairly young (new) the roots may not be fully establish (hold enough store sugars). If the dormant Bermuda grass doesn’t have enough store energy to out compete the Rye “winter” grass in the spring, there can be a negative effect. If you have to, or really want to over seed, just be careful with the scalping and most likely shouldn’t need to dethatch. You don’t want the Bermuda to use stored sugar in the roots to try and recover doing the fall right after the over seeding process.
But in the cast for already unhealthy struggling Bermuda grass rye can potentially indirectly help with Bermuda recovery in later spring/early summer. It cannot override watering issues, such as over, under or uneven watering. If that has been addressed along with other potential problems such as nutrition deficiencies, Rye is a quick cheap temporary fix. In the spring the rye will help Bermuda to fill bare spots for two reasons. The Rye grass will reduce evaporation from areas that would otherwise be bare. And, two as the rye dies and the roots get broken down, the soil becomes naturally aerated with will help the spread for the Bermuda,
Aeration can be another argument for over-seeding. Overseeded turf areas with foot traffic have less compaction issues that none overseeded areas with foot traffic. Over seeded lawns do take more water than none over-seeded lawns, but not as much as most people think/do. During the two or three month period that Bermuda is dormant Rye grasses needs aren’t much more that the Bermuda roots under them. Dormant Bermuda needs water one every 7 to 14 days. Rye should only need water once every 3 to 7 days.