You love your lawn and you love looking at its green lushness. But one day you notice that it looks like someone has sprinkled flour or talcum powder on parts of it, which is just weird. These patches grow, and suddenly you have a white lawn!
It can be quite unnerving how quickly it happens and assuming you aren’t looking at the first frost or snowfall of the season – “Why is my grass white?” isn’t an unreasonable question to be asking!
Why is My Grass White?
It’s very likely to be powdery mildew that’s turning your grass white. It starts as light white dust on the individual blades of grass, and from a distance, it looks like a powder of some sort has been sprinkled on your lawn.
OR it could be snow mold which is also white but looks more like a threaded webbing than a powder once you get close up to it.
OR it could be that your lawn is stressed from over-cutting and now the lawn is sick and looks lighter and whiter than it should.
The good news is that even if you see your lawn turning white, in all cases, it is completely rectifiable. The first thing you need to do is to properly identify the problem and then work out the best way to solve it. So, what causes grass to turn white?
Potential Causes of Grass Turning White
What causes grass to turn white? There are a number of factors that could be contributing to turning your grass white. You may have just one, or more likely a slow build-up of a number of factors that all contribute a little towards your sudden appearance of white grass.
Powdery Mildew
If you can see little white balls of dust-like powder sticking to the individual blades of grass, then there is a high chance that your lawn has been infected by powdery mildew. You are more likely to see sections of the lawn looking white rather than the whole lawn appearing uniformly white.
It’s really common in grass varieties like Kentucky Bluegrass. Powdery Mildew is actually a fungus, like a lot of other grass afflictions but it’s usually not too invasive.
Powdery mildew is most common in areas of your lawn that are in heavy shade for most of the day. You’ll find it around trees, buildings, and fences or places that don’t get much sunshine.
Low air circulation or lack of moving air can also be a reason powdery mildew forms. Parts of your garden that are in the shade and sheltered from any breeze are breeding grounds for powdery mildew.
Powdery mildew loves cool, cloudy conditions and thrives in high humidity. How much powdery mildew you get depends on the weather and garden conditions that you have.
Snow Mould
Don’t confuse powdery mildew with snow mold. Snow mold will look more like a webbing over the top of the grass rather than dust on each grass blade.
Both snow mold and powdery mildew look white on the grass but the snow mold will look more like strands than powder when you get up close. Hard to explain but as soon as you see it, you will know what you are looking at.
Stressed or Sick Grass
Sometimes, when your grass is really stressed from drought or overcutting, the blades appear to turn white. New sod that turns white is also a sign of stress. The pale white color can also be a sign that you need to adjust your blade height on your mower so you’re not cutting more than a third of the length of the grass blades each time.
Basically, you are looking at the pale sheath of the grass with no green blade growing from it.
It’s not pretty to see and can be quite distressing but it’s much easier to fix than other lawn diseases!
How to Fix White Grass.
Grass is a type of plant that needs a lot of light and plenty of open space to grow well. When it doesn’t get these conditions, it becomes susceptible to a number of diseases and problems. Once you create the right conditions again, the grass will easily spring back to life and grow lush and green once more. Here are some ways to fix white grass and how to treat powdery mildew on your grass!
Increase Amount of Sunlight
The number one reason you get molds growing on your lawn is a lack of sunlight. Mold can’t grow in places that get a lot of sunshine. Getting the maximum amount of sunlight onto your lawn is the best thing you can do to fight powdery mildew or snow mold.
Try cutting back branches, trees, shrubs, or plants that have grown up and are now creating deep shade on your lawn, if that’s practical.
Don’t Water at Night
Watering at night keeps the humidity high and that’s what molds love. Warm wet environments…Watering your lawn during the early morning hours gives the lawn time to dry off during the day and keep the moisture off the blade where the mold grows. Water your lawn well and regularly rather than lightly and daily.
Increase Air Circulation
Increasing the flow of air in heavily shaded areas will help, too. Cutting back plants that shade the lawn, trimming trees and branches that overhang your yard, or even putting in a fence that has mesh or lattice panels and can let air flow more freely are all things you can do to keep the air moving!
Reduce Nitrogen Fertilizers
For some reason, nitrogen-heavy fertilizer seems to increase powdery mildew activity. Try reducing or eliminating the amount you put on your lawn.
If you have a pretty open lawn but have powdery mildew, reduce the amount that you are using and see if it has any effect on the powdery mildew growing on the blades.
Use Powdery Mildew-Resistant Grass Seed
If you have a problem with powdery mildew try replacing or overseeding with powdery mildew resistant grasses like Kentucky Blue Grass, which is also a more shade-tolerant grass and good for those shady patches. Other grasses that may work in the shade are fine-textured perennial ryegrasses, fine fescues and ryegrasses, tall fescues, and good old Bermuda grass.
To find out what disease-resistant grass seed varieties are suited for the area you live in, ask your local county or university extension service for more information.
Grow the Grass a Bit Taller
If stress is the problem for your lawn, let the grass in shady areas grow a little higher than the rest of the lawn. When the blades are about 3 inches (7.5 cm) tall try mowing them lightly by about a third.
Dispose of Clippings Carefully
If you mow lawns with powdery mildew on them, please be careful of what you do with the clippings. You may inadvertently spread the spores to other parts of your yard (or worse yet, to the neighbor’s yard) by carrying them to the compost bin. Bagging them on the spot or getting rid of the mold completely before mowing again is your best option.
Leave a Reply