Pests and other pressures

After a long, brutally cold and snowy winter in some parts of the country, spring is finally here. So, we spoke with plant pathologist Jill Calabro about pests and other pressures on lawns and landscapes early in the season.

Q:  What effect has the past winter had on lawns and landscapes?

A: At this point I think it’s too difficult to predict. The weather conditions up until the middle of February in the eastern half of the country were pretty much a mild winter and then the middle of February and the first part of March, conditions have been very cold and very snowy in the eastern half of the U.S.

So I think at this point right now, it looks like from the Mid-Atlantic to the Midwest, up into the Northeast and New England, conditions are probably close to two weeks behind normal if not even a little bit further, especially up in New England where they’ve had so much snow.

Out West, conditions have been a lot warmer than normal. However, things have also been very dry out there. So when conditions are dry, generally pest pressure is a little bit lower in most cases but everything is warmer so things are sped up a little bit, especially in the Pacific Northwest and California.

Looking at the long-term forecast, what’s predicted is that finally an El Niño has arrived in the U.S. but it is a weak system of an El Niño. The prediction is that wetter than average conditions will be experienced along the Gulf coast states and along the Gulf states of the U.S. and drought conditions will continue out West.

Q: What does that mean for turfgrass?

A: Given the weather conditions we’ve had the last three or four weeks, on turf some of the things to look out for are damage from cold temperatures in the eastern half of the country.

Freezing damage or damage from cold temperatures is very possible on turf this year up in New England where they’ve had heavy snow cover and long term snow cover has protected the turf a little bit from freezing temperatures, however it has been going on for an extended period of time so that’s the first thing I would look out for is damage from cold temperatures to turf.

Any turf that’s along north facing slopes that are in saturated soils would be most prone to any kind of cold damage, and also turf with a fine texture to it would also be susceptible to cold damage.

Q: Which pests should technicians be on the lookout for early this spring?

A: Early in the season, it’s not so bad. There could be some springtime grub damage from grubs that were not controlled the previous season that can carry over. That’s something to look out for.

Q: What about invasive pests?

A: Definitely emerald ash borer is one to be looking out for this year. It has spread a lot. It’s spread into Colorado, southern Arkansas along the Louisiana border, even in Georgia now. It is continuing to spread so we’ll start seeing probably more positive identifications in areas that previously had not seen emerald ash borer. So definitely watch out for emerald ash borer but again, the signs of that pest you wouldn’t even notice early in the spring. That would be something you’d notice later in the summer, but if you live in an area where emerald ash borer infestations are known to be present, then treatment needs to occur in the spring.

Preventive, or even if it is present, curative treatments would need to be performed in the spring.

Pine mountain beetle out west is another big one to watch out for, at least for people in western states.

Q: What sorts of disease pressure can LCOs expect?

A: The second thing I would look out for coming into the growing season would be some of the cool season diseases. Things like snow molds, which don’t normally happen on non-golf-course areas but with the amount of snow cover up in the Northeast, that is a possibility this year.

So snow mold damage is one thing to look out for as well as red thread. I think red thread will be a little bit more common and in the really saturated soils areas where conditions are really wet, slime molds might be evident. It won’t hurt the turf but it can make it look a little bit different.

Ornamental diseases, at least for the full year diseases on woody plants, most will start in the early spring so trees and shrubs need to be protected once you have your first fully extended leaves. You need to start thinking about protecting leaves from ornamental diseases at bud break.

There are a lot of diseases that cause infection in the spring: rust and powdery mildews, anthracnose all start with early season infections.