(guest post by Valerie Smith for Sod Solutions)
Fall is right around the corner and with it comes cooler weather and family gatherings for the holidays. One of the best things you can do to ensure a beautiful, thriving lawn in the springtime is care for it during the fall. The experts at Sod University have compiled a list of some of the most important tips to help your warm or cool season lawn transition into the cooler months ahead. Be sure to also take a look at these fall lawn maintenance blogs written for homeowners who have zoysia, St. Augustine, bermuda grass, centipede grass, bluegrass or fescue.
1. Reduce Mowing for Deeper Roots
It’s actually recommended that you mow your lawn a lot less during the fall months. This is good for warm season lawns like zoysia, bermuda grass, St. Augustine and centipede grass. Keeping your warm season lawn slightly higher will encourage deeper root growth during the fall so that the grass will survive through winter dormancy.
For cool season lawns like bluegrass and fescue, a mowing height between 2.5–3.5 inches during the fall is ideal. This mowing height will also help prevent snow mold in snow prone regions. However, if it gets too long, it’ll create a mat layer, which is ideal for disease breakouts. To learn more about mowing heights for each grass type, visit the Lawn Mowing Guide.
2. Water Less as Temperatures Drop
It’s important to water your lawn less as temperatures drop as too much water can lead to disease. Temperatures change around this time of year so as temperatures drop, soil conditions also change. Fall is one of the most optimum times of the year for disease to start appearing—especially when over-watering and shade from fall leaves combine. Disease can be caused by a number of things, but it’s usually caused by over-watering, changing temperatures and shade.
Regardless of disease outbreaks, you’ll still want to water your lawn to prevent drought stress while the grass is actively growing. Even though your warm season lawn will begin to enter stages of dormancy, light watering will prevent dehydration. Warm season grass typically requires one inch of water per week including rainfall. In comparison, cool season lawns require about 1–1.25 inches of water per week including rainfall. Watering both types of grasses in the early morning will decrease the risk of certain turfgrass disease. If you would like to learn more about irrigation for each grass type, visit the Lawn Irrigation Guide.
3. Fertilize Your Lawn with the Right Nutrients
Fertilization differs this time of the year compared to the other active growing seasons (spring and summer). As previously stated, outdoor temperatures are starting to change—so are soil conditions. Your grass is a living thing that needs specific nutrients at this time. Warm season grass will likely enter a state of dormancy and cool season grass will still endure cold temperatures.
Sod University recommends two different fertilizer options for the fall, however, you will only need to use one of the two options for fall fertilization. The Fall Fertilizer Box, in particular, has three separate bottles of liquid fertilizer in it that help your lawn recover from the hot summer temperatures it just endured as well as prepare for the colder temperatures ahead. You can read more about The Fall Fertilizer Box and it’s mixture of nutrients in a separate Sod University blog here.
Lawnifi Foundation is a slow-release granular fertilizer option that comes in a 25-pound bag and lasts for three months. With a 29-0-5 NPK formulation, Lawnifi Foundation is an ideal granular fertilizer for lawns and gardens. The two percent iron included in Lawnifi Foundation’s mixture helps plants carry oxygen throughout the leaves, roots and other parts of the plants to promote a green, healthy lawn. Featuring slow-release nitrogen, Foundation gradually feeds your lawn over an extended period of time without overwhelming your lawn with nitrogen during the fall.
4. Control Weeds with a Pre- or Post-Emergent Herbicide
Your warm or cool season lawn has just made it through the summer months when herbicide applications damage grass due to hot temperatures. Now that it’s starting to cool down, you are free to apply both post-emergent and pre-emergent herbicides without risking any damage to your lawn if applied properly. You may even notice that the weeds from summertime are starting to die off. Unfortunately, there are winter weeds that will start to pop up when the months are colder too. We recommend applying a pre-emergent during the fall to prevent winter weeds.
Some hard to control weeds that may appear around this time include Poa annua, sedge, crabgrass, goosegrass, chickweed or henbit. There’s a difference between pre- and post-emergent herbicide control for weeds. A post-emergent herbicide controls any current weeds you are experiencing whereas a pre-emergent herbicide, as its name suggests, serves to prevent weeds from appearing.
Fall is actually the best time to apply a pre-emergent—especially if winter weeds have been a big problem in the past years. You can also do this in the springtime around March or April. Check out some pre-emergent products listed in this article online and be sure to read labels thoroughly before application. Read more about pre-emergent applications in the fall in How to Use a Pre-Emergent Herbicide in the Fall and learn about the various types of weeds in Identifying Common Lawn Weeds.
5. Keep an Eye Out for Insect Invasions
Although there could be a variety of insects that may be invading your lawn at this time, the main ones to look out for include grub worms for both warm season and cool season lawns, as well as chinch bugs. Chinch bugs are usually the most active in the months of June–early September, but may still be present in some lawns such as St. Augustine. Other insects that may appear in the fall are sod webworms, fall armyworms and mole crickets.
If you have insect activity, treat with a broad-spectrum insecticide labeled to treat the insect you are seeing. We’ve listed a few in this article online. Be sure to read product labels thoroughly before application. If you use a granular variety of insecticide, water the lawn immediately after application to help with absorption. Visit the Insect Identification blog for more details.
6. Prevent Disease Outbreaks as Temperatures Change
We recommend applying a systemic fungicide at preventative rates around the beginning of the fall season or right beforehand. This helps the grass enter colder months in a healthier condition by keeping disease outbreaks at bay.
If you’ve had a problem with disease around this time before, you may need to make multiple applications of the systemic fungicide in affected areas. If spring dead spot was a problem during the spring, apply a fungicide at high rates to the problem area(s). Spring dead spot is caused by a disease that damages grass during the winter—you just can’t see the damage because the grass is brown and dormant until the spring when everything greens up again. Applying a fungicide at a preventive rate will keep it from coming back.
Consider mapping those areas because fungicide treatment can be expensive. If you use a granular variety, water the lawn immediately after application to help soil absorption. Above all, read product label instructions thoroughly before application for detailed instructions. If you have a warm season lawn, be sure to check out the Sod University blog, Beware of Late Fall Fungus for Warm Season Lawns. For generalized disease control information, read Lawn Disease Control.
Tip: Remove any dead leaves. As dead leaves accumulate on the ground during the fall, they create shady, darker spots on the lawn. Light cannot reach these areas and moisture becomes trapped. This quickly damages the grass underneath these spots. When warm season grass goes dormant, it can be difficult to notice any discoloration after the leaves are removed. Come springtime, you will notice the damaged areas while the rest of the grass turns green again. Depending on how many trees are nearby, consider raking once a week. Learn more here.
Fall lawn maintenance differs from that of spring and summer maintenance. With the changing of the seasons also comes the changing of temperatures, weather and soil conditions. It’s important you make these changes in maintenance so that your grass is prepared for the cooler months ahead. For more specific information for each grass type, view fall lawn maintenance tips for zoysia, St. Augustine, bermuda grass, centipede grass, bluegrass or fescue.
Want to learn more about achieving a great lawn? Check out more Sod University tips here.
Editor's Note: Sod Solutions has helped successfully develop and release to the market over 20 different turfgrass varieties over the past 27 years including PalmettoⓇ and CitraBlueⓇ St. Augustine, EMPIREⓇ and InnovationTM Zoysia and CelebrationⓇ, Latitude 36Ⓡ and NorthBridgeⓇ Bermudagrass. The company is based in the Charleston, SC area.