Springtime means mowing...and mowing again

Posted by: Alison O'Connor, Larimer County Extension

When it comes to the lawn, I'm a total Lawn Geek. I love my lawn. I'm pretty sure it stems from my days mowing lawns when I was a kid. My brother, Jeffrey, had a business called the "Lawn Ranger" and he gave me a few select clients (read: clients he felt weren't as lucrative to him). I love the smell of fresh cut grass and my sneakers stained green from all that chlorophyll. Maple the beagle also enjoys her green feet.

Maple pretending to be disinterested...but she's really proud of her green paws!

But this time of year, it's tough to keep up with the lawn and how quickly it's growing. Cool season grasses, like Kentucky bluegrass and tall fescue, seem to grow inches overnight and mowing the lawn to keep it tidy can seem like a chore. Plus, you're trying to time mowing between rain showers. Recently, it seems I've rushed home from work to mow, only to find that the lawn is too wet from a shower that blew through. Drat.

At each mowing, obey the 1/3 Rule. This means you don't remove more than 1/3 of the total leaf tissue. This helps keep the lawn neat and prevents hay piles. What this also means is you may have to mow two or three times each week in the spring since the grass is growing so fast. (For someone like me, it's great! For others, this is where mowing becomes a pain.)  NOTE: Those who do mowing for a living - commercial mowing and landscape firms, parks, etc. - mow on a schedule and sometimes can't stick to the 1/3 Rule. This is real life. Fortunately, the grass survives!

A comparison of mowing heights. The photo on the left is how tall the lawn was prior to mowing. The middle picture is ignoring the 1/3 Rule and cutting it too short. The photo on the right is mowed at the proper height for the height of the lawn.

Hay piles are ugly, often clump together and can discolor the grass. Worse, hay piles means you've removed too much plant tissue, which can stress your turf. Stressed turf is more susceptible to drought, weed pressure and disease.

(Not my yard!) Hay piles. We've all done it, but try to avoid this by obeying the 1/3 Rule.

Worse than hay piles are scalping the turf. This means you're essentially removing ALL of the leaf tissue. Doing this in the spring, even once, can result in the turf struggling all season. Don't scalp. Raise your mowing height!

I couldn't bring myself to fully scalp the lawn, but you get the idea. This is just a bit too short and the lawn will get stressed.

Over the weekend, I cut the lawn with the mower set at its highest height. The lawnmower was still sputtering and choking (so was I, for that matter). Once you get the lawn height under control, mow regularly to keep it at that height (still obeying the 1/3 Rule). Once the spring growth rush has passed, set your mower at one height all year and keep the grass at 2.5 to 3.5" tall, depending on what you prefer.

Ahhhh....fresh cut grass!

Mulch your grass clippings back into the turf. Mulching keeps fertilizer (and pesticides) in the lawn system and provides free nutrients! Grass clippings are mostly water and do not add to thatch problems. I only bag my clippings a couple times of year--when the grass gets too tall and mowing nearly kills the engine and also when I want to use clippings in the garden (or feed them to the chickens).

The garlic is lovin' the grass clippings!

Lizzy is a Lawn Geek too!

So there you have it. Maple was a good citizen and helped me mow the lawn and kept track of the height. I mowed once on Sunday and again on Monday, just to reduce the height and get the lawn a bit more tidy. You can see my progression below.

It's good to use a beagle as your measuring device for your lawn. At least the lawn isn't up to her knees anymore!

Hort Peeve: New Sod Torture

Tony Koski, Extension Turf Specialist

The lawn before mowing; that blue flag is 12 inches tall!

This turf peeve is about the mowing of newly planted sod. For some reason, the principles of proper mowing height and frequency are often totally neglected with new sod - sometimes for weeks on end. I’ve been watching the sod that was planted during the renovation of the old Fort Collins post office landscape over the past 6 weeks. The old lawn was replaced with new bluegrass sod – and then taped off as if it were a crime scene. The new sod went unmown for about 3-plus weeks – but was liberally irrigated during that time. As you might expect, it grew tall….VERY tall. So tall, in fact, that it began flopping over (aka “lodging”).

The lawn an hour after mowing torture

The lush, floppy, dense grass was recently mowed to a height of about 3 inches. What was left behind is not pretty – a mess of wet, matted, rutted brown and yellow grass. Mowing in this fashion will kill roots – roots that have been formed in just the previous few weeks. The stressed turf must not only grow a bunch of new leaves and shoots to replace those that were hacked off during mowing – but also will have to produce new roots to replace the ones that died as a result of the severe mowing.

This first mowing left few green leaves...and what happens
when the 1/3 rule is violated so egregiously!

This turf torture occurs all too frequently when new sod is planted. For some misguided reason(s), mowing of the newly planted sod often doesn’t happen for 2-4 weeks following planting. Sometimes the sod supplier tells a client it is better to leave the sod unmown for weeks on end because it will form better roots than if mowed “too soon” (not true). More often it is out of laziness, neglect or fear that new sod isn’t mowed. Because new sod should be irrigated daily, the water must be turned off for a day prior to mowing to give the sod a chance to dry out a little. This temporary drying out of the new sod takes planning and coordination with the person doing the mowing – and it creates the (unjustified) fear that the short-term drying will harm the turf.

The truth is, grass should always be mowed when it needs it – to avoid removing any more than 1/3 of the turf height at a single mowing (we call this the “1/3 rule”) – even if it is new sod.  Luckily, newly planted bluegrass sod is amazingly forgiving of neglect and mismanagement – so this lawn will likely survive and (eventually) look good. I will keep you updated.

Here is the lawn 1 week after its first mowing. Still recovering
from misinformed (stupid?) management. This is someone's
idea of proper turf management?