Bentgrass plus drought plus heat, means dead patches on lawns

When we receive unseasonably high heat and dry weather, these conditions cause bentgrass and other annual weedy grasses in lawns to brown out much earlier than we normally see it. If you are seeing areas on your lawn yellowing or browning right now, there is a good chance it is Bentgrass (Agrostis stolonifera),  or one of its close cousins, Poa Annua (annual bluegrass) or Poa Trivialis (Rough Bluegrass).bentgrass poa annua 006 with writing

Bentgrass and Annual Bluegrasses,  can invade a lawn through use of a low-quality seed mix, from sod (more commonly found then anyone likes to admit) or from a nearby golf course.  These weed grasses are encouraged by too frequent, shallow-watering.  Golf courses use bentgrass because it doesn’t mind being mowed very short (so the ball can roll).  They can spread quickly through a lawn during cool, wet weather, taking over areas where the rest of your grass isn’t doing well. But it is helpless against heat and drought. Once that weather hits, an invaded lawn will start to brown out in large, uneven patches.

Here are some tips on identification, and what to do about Bentgrass in your lawn.

The damage in this lawn is easily identified. The dividing line between healthy and dead grass is sharp. You can also see that the blades of the brown grass are much thinner than those of the healthy grass. Bentgrass also roots shallowly, which just makes droughts worse as its root structure quickly dries out in the top level of the soil, while the more deeply rooted desirable grasses remain protected deeper in the soil profile. This patch pulled right out when Kyle tugged on it.

The only way to deal with Bentgrass is to replace it with more desirable grass cultivars. If you have a dead patch now, there is nothing to do but rake it all out, loosen the soil, and reseed with a proper seed varietal. In the future though, you can avoid ugly brown patches like this by dealing with patches of Bentgrass before they die. In the early Spring, when everything is going well, you can find Bentgrass when it is healthy and green. Look for patches of lighter-coloured grass with the characteristic skinny blades. The shallow roots make it easy to pull out at this time, too.

Patch of annual bluegrass - Poa Annua

Patch of annual bluegrass – Poa Annua


Finding a patch early in the year gives you time to spot-seed the area while giving the desirable  grass time to establish itself. Then by the time the heat strikes, you will have stronger grasses among the weak bentgrass. This method also avoids making the kind of large area of open earth that weeds consider an open invitation to take root.

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    2020 is now behind us.  Together with our customers, we face Covid-19 head-on as a community-minded local small family business and are extremely grateful to be able to survive and keep all of our loyal employees working hard with us through it all.

    2020 threw everything bad that it could at us:

    • Nine days of snow, ice and wintry weather in May.
    • One of the hottest driest summers on record with long spells of grass-killing heat and drought. Read more here in our 2020 summary blog.
    • A bumper crop of crabgrass that germinated in the perfect (rainless) storm.
    • Chinch Bug numbers were record breaking and persisted through the dry heat they love, secretly killing lawns while dormant! We can help with Chinch bug damage
    • We put together an easy to read lawn care service timeline that you can use to know when to expect us for each scheduled service in your package. 

    I want to reassure you that in every decision we make around COVID-19, our number one priority remains the health and safety of our employees and customers.  Safety, Integrity and honesty are our most important core values.  We will continue to follow strict safety guidelines that ensure “zero touch”.  We will not let our guard down on exercising our safety protocols!

    Thank you all for your understanding and extra patience during these challenging times. Our team works hard, so if you are met with our exceptional service from our technicians or office team members- please give them a thumbs up to make them smile or let me know through a quick email to

    We thank you for supporting our local, family-owned business of 31 years.
     genuinely appreciate each and every one of you and promise that we will do our part to ensure our mutual safety and look forward to be back on your lawn as soon as possible this Spring

    Thank you in advance,
    Kyle Tobin
    Chief Environmental Officer