Powdery Mildew, Powdery Baking Soda


It’s getting cold here in the Wonderful World of Weed Man! Autumn is most certainly upon us.  The air and leaves are crispier, the wind is blowing, and pumpkin spice is ever present.  Even though the temps have dropped, your lawn is still alive and taking in nutrients in preparation for the winter.  Now is still an important time to maintain the health of your lawn.

Let us help you achieve that by continuing our series on lawn disease.  We last wrote about Rust Fungus, and this week we will talk about a similar type of fungus – Powdery Mildew.  They have a few similarities, including appearing as a powdery substance on your grass blades.

If you were to take a look at our website, you would find this lawn disease describes as,

“Powdery mildew is a damaging disease of blue-grasses and fescues. Periods of low light intensity and poor air circulation favor the disease. Heavily shaded areas are particularly susceptible.” 

You are most likely to see powdery mildew during the spring or fall when temperatures are lower.


Powdery Mildew – even with good fertilization, mowing, and watering habits, still shows up from time to time in my lawn.  When it shows up, it only shows up in one place in my lawn.  The heavily shaded area on the north side of my property.  It gets little sunlight, and poor air circulation due to the position of my house and the fencing attached to it.

It is a fungal disease that looks just like it sounds.  It is fairly easy to identify

  • Grass blades look like they have been dusted with white powder like baking soda
  • Powdery mildew will start off as spots on the grass blade
  • The white spots will spread to cover most of the upper part of the grass blade

powderyInterestingly, powdery mildew does not require much moisture to infect plants like other fungal diseases do.  Poor watering habits is typically a contributing factor to lawn disease, however in this instance you could water well and still run into this disease.  Powdery mildew, though typically does not, can cause damage to the lawn if it is severe enough.  As the fungus covers the grass blade it will disrupt photosynthesis.  As the plant weakens, it will become even more susceptible to other lawn diseases or issues.

The ‘interwebs’ are full of advice on how to deal with powdery mildew.  I found a curious DIY ‘organic’ solution made from Baking Soda.  I cannot professionally account for the success of such a mixture, but apparently if you mix baking soda, water, vegetable oil and dish soap you will create a concoction to combat this disease!  For those of you who would like a less involved approach to resolving powdery mildew you can do as follows –

Once discovered in your lawn, there are some easy steps to clear up the disease:

  • Implement recommended watering habits – deep and infrequently
  • Keep a high mowing height to promote a healthier root system that can withstand disease better
  • Reduce the amount of shade by trimming trees and shrubs that contribute to the shady areas
  • Increase the air circulation by thinning trees and shrubs or making appropriate changes to landscaping to promote air flow in the area of concern
  • Provide a light application of fertilizer to help promote recovery.
  • Reduce thatch with core aeration
  • There are fungicides that can be applied to help recover, however they can be very cost prohibitive to do.

Although there are chemicals that can help control fungus in the lawn, we generally do not recommend it.  There is a time and place for use of chemical treatment, but too often homeowners just want a quick fix.  Many times chemical control for fungus treats the symptoms and not the underlying cause.  Chemical control can get very expensive as it needs applied consistently and often to work.  If you make the necessary changes to your cultural practices it will improve on its own.

If you are seeing powdery mildew in your lawn, and need some help with it, don’t hesitate to call the Weed Man! 208-888-9911 www.weedmanboise.com #wecareforyourlawn











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