Turf will begin to recover from the stresses of summer and grow more vigorously. Several conditions may exist in turf that need to be addressed, such as weeds, compaction, thin areas, etc. Do you have a complete plan in place to address all of your turf problems? This is the optimum time of the year to address most lawn issues, so you should re-examine your program to ensure the best results.
While this time of year is not the best time to soil sample, it can still be done effectively, especially if you plan on renovating or aerating a lawn. By taking a soil sample, you will be able to determine if the soil pH is optimum (between 6.0 and 7.0). Additionally, the need for phosphorus or potassium will be indicated by the soil test as well. Lime applications work best when incorporated into the soil, and aeration is a prime time to get it down into the soil profile.
Fall is the best time of year to control most weeds. Hard to control weeds like ground ivy and wild violets can be controlled best with fall applications of herbicides. While spring is a necessary time to control clover, dandelion, and other summer annuals, perennial weeds will be better controlled in conjunction with a fall application. Check the label of 2 or 3-way herbicides to make sure your target weeds are on the label. There are some great products available to control most broadleaf weeds. Remember to add a surfactant if the product recommends one being added.
While not always possible, it is important to perform aeration when soil moisture is optimum. If soil is too dry, tines will not go deep enough to make a real impact on soil compaction. You also run the risk of breaking tines or your equipment. If the soil is too wet, you may further create compaction, as most ride-on aerators are well over 1,000 lbs. Make sure that soils are somewhere between dry and wet, so that a full-length core (2.5-4 inches) can be pulled. Finally, make sure that you are pulling enough cores over a lawn. Depending on your aeration equipment, it may be necessary to go over a lawn several times.
Most lawn aerators are designed to move quickly; 3-5 mph. While these units can cover a large area in a short amount of time, have you ever considered what impact they are actually having on the soil? Look at the chart and see the relationships between tine size and tine spacing. The majority of lawn aerating equipment comes standard with ½" to ¾" tines, on 4" x 8" spacing. It may appear that there are lots of tines on the machine, but it is clear that a small amount of area is impacted by one aeration pass. For example, only 1.38% of the surface area of a lawn is impacted by an aerator with ¾" tines and 4"x8" tine spacing. In order to really make an impact on a lawn and alleviate compaction, you should target a higher percentage. A good number to target for lawns is 10%. Golf superintendents shoot for 15-20%, but the equipment used on golf courses are typically piston-type aerators that move slow.
While it may not be economically feasible to make 7 passes over a lawn, it may be in your interest to make 3-5 passes. This is something to keep in mind for high-value properties, athletic fields, or properties that need serious attention or renovation. Depending on your equipment, it may not be possible to change your tine spacing, but can you change your tine size? It may be in your interest to do so. As you can see, simply changing from ¾" to 1" tines almost doubles the surface area impacted. Customer satisfaction is of primary importance, so educate your clients on what you are doing and how it will make a big or bigger difference next year.
Table 1. How Tine Size and Spacing Affect Surface Area of Turf Being Aerated
|Tine Size||Spacing (inches)||# Holes per Square Ft||Surface Area Impacted by One Tine||% Surface Area Impacted||Number of Aerifications Needed to Reach 10% Surface Area Impacted|
|1/2"||2 x 4||18||0.196||2.45%||4.1|
|1/2"||2 x 8||9||0.196||1.23%||8.2|
|1/2"||4 x 4||9||0.196||1.23%||8.2|
|1/2"||4 x 8||4.5||0.196||0.61%||16.3|
|3/4"||2 x 4||18||0.441||5.51%||1.8|
|3/4"||2 x 8||9||0.441||2.76%||3.6|
|3/4"||4 x 4||9||0.441||2.76%||3.6|
|3/4"||4 x 8||4.5||0.441||1.38%||7.3|
|1"||2 x 4||18||0.785||9.81%||1.0|
|1"||2 x 8||9||0.785||4.91%||2.0|
|1"||4 x 4||9||0.785||4.91%||2.0|
|1"||4 x 8||4.5||0.785||2.45%||4.1|
One final thing to keep in mind is proper seed selection. Make sure to select the proper species of grass for the location. There are no seed mixes or blends that should be used everywhere. Match the type of seed that you will put down with what is already present, or what you are converting to. The saying "you get what you pay for" usually bodes true with seed. Seed prices have skyrocketed over the past few years, but that doesn't mean you should buy what is cheapest. Do your research; look at NTEP (National Turfgrass Evaluation Program) data and select seed by the location of turf. Otherwise, you may find yourself doing it all over again, or trying to remove grass you put in the year before.