Northern Delaware. I usually cut down to 4", but this season I've left my mower (Scag Liberty Z) at max height which is around 5" I believe, and the grass looks pretty good. Are there any real drawbacks to keeping the grass taller? Seems to handle periods without rain better. A lot of people seem to cut fescue shorter (even down to 3") and I don't really get it.
Also tangential fescue question: My lawn is nearly exclusively TitanRX Tall Fescue at this point. They have a new GLX variety out that's supposed to be more fine and a bit darker. Does anybody have experience with GLX, and do you think it'll mix okay with an RX lawn if I start overseeing with that going forward? I want the benefits of the new gen but also don't want patchy color mismatch.
by clingbat
15 Comments
The higher you cut it the better it looks. The higher it is the more canopy / cover it has so it protects the roots better.
FWIW, keeping it taller has also really helped reduce weed growth.
Landscapers do not want to adjust their mowers from lawn to lawn.
You can get increased fungal pressure with taller grass. Thats the only downside. I mow mine at 4 and like it. 3.5 is my favorite but we’ve gotten little rainfall so it’s been 4 inches for the past month or so
Every deck is different but we run scags in Wisconsin and cut fescue at 4-4.5 in. A lot of lawn companies will “drop the deck” in summer/ drought periods to continue to mow every week. I prefer to skip weeks mowing and make up revenue in weed control/ side projects
I personally think shorter and more dense growth looks better, but that’s only doable with warm season grasses or kbg with a lot of maintenance.
But with fescue, you’re right, taller is better. I think 4.5 inches is the sweet spot for fescue. The taller the fescue, the deeper its roots can grow and the better it can keep itself cool in hot weather. Most people aren’t aware that grass sweats through its blades to regulate temperature. That’s why water is even more important in the summer, it uses it for not only growth and to sustain biological functions, but to cool itself off.
I have 4th Millennium Tall Fescue mowed at 2.5 in and it does well … with irrigation.
Taller is better, 4-5″ max. It allows for better growth of the roots, less stress overall, and protects the soil surface and sub-surface biome and moisture levels. Also makes a for a thicker stand, and that can help prevent weeds from establishing..
A couple of things to note:
– A lot of fescue will start laying over under its own weight at greater than four inches.
– Most pop-up sprinkler heads are 4″, so if you’re mowing it at 5″, there’s a chance your sprinkler is going to be blocked by the grass around it, requiring you to cut it shorter around the heads for clearance.
– A lot of residential mowers max out at 4-4.5″, making 5″ not possible with most homeowner’s equipment.
Overseeding? Your new lawn looks terrific! It’s thick and green. If you keep it that way why overseed? OK, yes, eventually age will take a toll. By then there may an even better cultivar. Deal with it if and when the need arises. It might be so far in the distance you will want to upgrade the whole lawn. If you choose to overseed I doubt there will be much color difference, genetically. Soil fertility will have more impact on that.
I had a turf science prof who said the lower the height of the grass the more savy management must be. Think about a lawn’s total leaf surface. How many cubic feet of green blade? That’s the size of the food factory. Tall grass has capacity to manufacture more food for itself – assuming sufficient water and nutrients. Short grass needs constant attention because it struggles to maintain itself. Golf course superintnedents work where the grass is a quarter to one-and-a-half-inches tall. They make big money to keep it green, healthy and playable. And they have big budgets to assomplish it.
I keep mine 3.5 to 4. I will take it lower if things are really wet, Down there where the grass lives it’s a jungle and sometimes we need to get some air down in there to avoid fungal and other problems at a level that never dries out. It’s a spring and fall consideration. Summers for me ae always tall for the shade. And I normally go short at the end of the season. There’s no need for all that vegetation to flop over and/or snow to bury it. Nothing good can come from it.
The other thing with tall(er) height of cut is standability. It’s a small consideration. Keep soil pH right and potassium levels adequate.
Ideal cut length 3.5 to 4 inches. It may feel weird leaving tall fescue this high. But try to get use to it. Is their golden length.
The only downfall to mowing higher than 4’ is the increased risk of fungus/disease during very hot/wet conditions.. if your keeping and eye on those things and treating properly your only benefitting from mowing higher. Enjoy!
I like my fescue around 3-4” keeps it lush and retains moisture better
Fungus infection during the rainy season?
Central Delaware. I mowed mine at 3” earlier in the season, just increased to 3.5” a week or 2 ago. I’ll probably bump it up to 4” in mid-June depending on the weather.