This post documents how I keep a healthy tall fescue yard in San Diego County, California which is in the transition region. Adjustments may need to be made for lawns in locations other than San Diego County.
If something in this post in incorrect or if there is a better way, please add a comment to the end of this post.
Enjoy your yard! You've put in the effort - you deserve it!
And brace for the heat. Once daytime temperatures exceed 90 degrees, fescue will become highly stressed. The grass blades will curl up and turn brown to protect the plant. Since fescue is deep-rooted (up to 3 feet), the plant is not dead but is very stressed. Once daytime temperatures drop under 90 degrees again, the brown grass will recover and turn green again.
Make sure to continue mowing the grass at a 4 inch height.
July - September
There are additional things that can be done to protect the yard. I typically don't need to do this in my area, but it may help your yard.
5-10-30 Fertilizer plus Iron: Since this is low in nitrogen, it is safe to apply during the summer. 30% Potassium helps the grass fend off heat and drought.
Humic Acid: This increases the soil water retention capability, increases nutrient holding capability, and excites microbes that encourage nutrient exchange between the plant and soil. Fulvic acid produces a very similar result.
Hydretain: converts moisture to water droplets the grass can use. It sucks the humidity out of the air to reduce water needs and is often used by golf courses to reduce water bills.
September
Time to start preparing the lawn for fall!
Start the process of getting rid of any Bermuda grass and other undesirable plants. This requires three yard treatments spaced three weeks apart so it needs to be started no later than September 1 in the San Diego area.
1. Cut the lawn at 2 inches tall
2. In a sprayer, mix:
a, Pylex herbicide (kills Bermuda grass, Dallis grass, crab grass)
b. Triclopyr (kills ivy, clover, etc)
c. Drive XLR8 (kills all of the above)
d. An adherent such as Crop Oil Concentrate (Sure Fire Crop Plus) or Menthylated Seed Oil (Prime Source Duo Stick Select)
3. Spray the mixture on the entire lawn then do not water for 24 hours afterward
4. Repeat this process three times, three weeks apart
Note that this will kill most of the plants listed above but there may be some remnants that come back the following year. For this reason, the process will need to be done several years in a row.
Other things that can be done:
Consider applying a fungicide to prevent fungus and disease (example: Scott's DiseaseEX).
A liquid aeration product such as Chemwise Simple Aeration plant food (0-0-8 + 1.5Fe) can also be used.
October
With the lawn still at 2 inches tall, aerate the entire lawn.
Two to three weeks after the last application of Pylex and Triclopyr, overseed the entire yard. When this is done, the ground temperature must be between 50 to 65 degrees, which equates to an air temperature of 60 to 75 degrees. It is recommended that 1 pound of tall fescue be used for every 100 square foot of ground. I have used Medallion Tall Fescue with great results.
Use a fertilizer with a high middle number immediately after reseeding.
November
The lawn can now return to being 3 to 4 inches tall.
The lawn should go dormant in the winter with little mowing or other maintenance needed until February or March of the following year.
I have used the steps outlined in this blog post to maintain a nice tall fescue yard. It is not perfect, but I don't have time for 'perfect'. Enjoy!
