A Greener View: Mysterious culprit digging in yard
Oct 26,2007 00:00 by Jeff_Rugg

Q: I would love for you to solve this mystery. Lately I'm finding small clumps of turf pulled out. At first I thought it was a mole or gopher, but I don't see any tunnels beyond the removed clump. I read that moles prefer areas that have a grub problem. I did fight the grubs last month; however, some of the lifted little clumps are in healthy lawns as well.

Well, first I guess we need to rule out that someone in the family is not secretly spending time in the yard practicing their golf swing or football moves while wearing spiked shoes.

The only other animal type that would be digging up small clumps of grass is going to be a mammal. If you had grubs and possibly still have grubs, then it could be skunks, opossums or raccoons. But they all tend to be less tidy and usually dig large patches of grass rather than small ones. Occasionally deer, dogs and other large animals paw at the ground and loosen tufts of grass; however, commonly this kind of damage is more extensive in one spot and not scattered around the lawn.

The most likely choice at this time of year is squirrels. They bury nuts in lawns and flower beds by digging small holes. They won't dig very deep or wide. They also don't leave a nut in every hole, so you might not find anything if you check. Sometimes other squirrels remove the nut and rebury it in a new place. Squirrels are squirrely and sometimes seem to just dig for the fun of it. There is nothing you can do about it, except sometimes eat squirrel stew.

Q: Recently, after walking around in the backyard, I noticed a strange dark brown powdery substance covering my shoes and feet. I am assuming this is a rust fungus. Could it be dangerous to the health of humans and animals in anyway? How can I eliminate this from happening? Is this harmful to our lawn if not treated?

A: I have never heard of any health problems arising from lawn fungal spores. If someone was allergic to mold, then I suppose there could be a problem since this is a type of mold. We are all exposed to fungal spores floating in the air all the time, but as you have seen, the lawn rust fungus is very prolific.

Walking through an infected lawn will turn your shoes orange or brown as you rub the spores off the grass blades. If you look at a blade of grass after you rub the spores off, you will see raised bumps where the fungus broke through the grass blade to release the spores.

This disease mostly affects ryegrass, but can grow on some bluegrasses and zoysia grass. Warm weather with heavy dew in the morning as well as overnight irrigation water allows it to spread rapidly. Interestingly, lawns most susceptible are mowed too low, lack water and need fertilization. It is usually a summer problem, not a fall problem.

Lawns affected by rust are more likely to be damaged by winter weather. Fixing the problem in the summer will help the lawn later. At this time of year, you can still start some watering and fertilizing after your first frost.

Sometimes only shady areas are affected. Lawns sodded in the front and seeded in the back may only be affected in the back. Sod is usually a blend of grasses that doesn't include ryegrass. Seed mixes are often a mix of bluegrass, ryegrass and fescue. The ryegrass is what turns up orange with rust first.

The nice thing about rust is the fact that it is a slow growing fungus. Next spring, if the lawn is fertilized and watered, the grass can outgrow the disease. Before the fungus can mature enough to release spores, the blade grows long enough to have the infected portion mowed off. Remove the clippings for a few mowings to slow the return of the disease. In severe cases, a fungicide can be sprayed weekly until it is gone.

E-mail questions to Jeff Rugg at info@greenerview.com.

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