Monday, August 18, 2014

Things that make you stop and say "Huh!"

Posted by: Tony Koski, CSU Turfgrass Specialist

As seen on the CSU Campus...What is causing the pine needles to stand upright in the soil? Any guesses?

Monday, August 11, 2014

August 11, 2014
Posted by: Mary Small, Jefferson County Extension

Got Mushy Raspberries?

They’re here and they’re gross. I’m talking about the spotted wing drosophila (SWD) in our Research and Demonstration garden’s raspberry planting.
SWD ovipositor, serrated and sclerotized

Of course, these little gems have to be different than other fruit flies. The females have a sclerotized (hardened) serrated ovipositor, (egg-laying structure) just right for laying eggs in intact, still-ripening fruit. They couldn’t be like their relatives who are more interested in fallen or overripe fruit, no!

What’s so disgusting about the whole thing is that the larvae rapidly turn raspberries into a liquid mess. One morning, a staff member collected a small bag for a snack later in the day. When she went to eat them, the now liquefied fruit was infested with tiny white maggots.

Liquified raspberries with maggot (just above center)

While they will damage many types of small fruit, peaches and cherries, they prefer the volatiles of raspberries. To add insult to injury the insects feed on other soft- fleshed fruit found in our landscape – elderberries, chokecherries, mahonia and honeysuckle. So there’s plenty of food to keep them hanging around, even if it’s not their favorite!

We first found SWD late last summer and began a sanitation program: keeping fruit regularly picked and collecting fallen fruit from the ground. We started a trapping program in July using a yeast-sugar water bait placed in red-lidded empty peanut butter jars. (Thanks to my dedicated family for eating all the peanut butter!)  While we’ve collected mostly male and female SWDs, it is interesting to see who else likes the bait. So far, we’ve also collected sap bugs, earwigs and other fruit flies. 
Trap for SWD 

This year we’re using sanitation and trapping to monitor the population and sort-of manage it. Being a garden on public property that can be accessed virtually any time of day, we’re a bit reluctant to introduce pesticides.

One of the benefits of the infestation is that we have a living laboratory for training our volunteers.  The clinicians will also be able to identify the adults after an upcoming workshop, so they can better assist customers.

And frankly, when I check the raspberry fruit I am amazed at how many thrips are wandering around in them. I wonder how many I've consumed over the years.  Maybe I should just view SWD in the same way – extra protein, anyone?

Wednesday, August 6, 2014

Earwigs: A case of "Ewwww"

Posted by: Alison O'Connor, CSU Extension in Larimer County

There are certain insects that seem to like to jump out at you and say "Boo!" Earwigs are one of those--they hide in small spaces and make their appearance known by quickly crawling away. And they always seem to show up in unexpected spots--like tucked in the bloom of a peony. The species we see in Colorado is the European earwig (Forficula auricularia). Even though my BFF Carl Linnaeus named this species back in 1758, it doesn't mean I have to like them.
European earwig (photo courtesy of Whitney Cranshaw)
Earwigs, characterized by their rear-end "pincers", cause damage to a wide array of plants, including ornamentals and edibles. Their pincers, by the way, are not dangerous--they use them for mating. These insects pose no threat to humans (except for increasing your heart rate when you come across them in damp, dark areas), but they are a nuisance both indoors and out. It has been reported that if handled, their bite is mildly painful. So don't handle them. Why would you want to handle them??
Boo! Earwigs in a peach.
(photo courtesy of University of Nebraska Dept of Entomology)
It's been a darn good year for earwigs. At the farmers' market, it seems we get at least one or two questions each week on "Something is eating my plants, but I don't see any bugs!" That's because earwigs are nocturnal feeders. They come and munch on your garden buffet at night. And mid-July to mid-September is the prime season to see damage. Why are they so rampant this year? My guess is it's because of our wet weather.
Earwig damage on common mallow
(photo courtesy of Whitney Cranshaw)
Earwig injury to peaches
(photo courtesy of Utah State University Extension)
So if you're seeing feeding injury on plants, but aren't sure what might be causing it, try setting out earwig traps. This is a fun and enjoyable project for the entire family. You can use rolled up, moistened newspaper or corrugated cardboard. Place in the garden and unroll in the morning to see if you caught any (or just throw in the trash if you're squeamish). Another option is to put a small cup of oil (vegetable, canola) in the garden, in a shallow hole. Make sure the oil is at least 1" below the soil surface. The earwigs will fall into the cup and drown in the vat of oil.
Earwig newspaper trap
(photo from
Dr. Whitney Cranshaw, our state entomologist, is doing some research this summer using various oils and other condiments. For now he recommends using oil (vegetable, canola, mineral) and even add a dash of soy sauce. A couple years ago he caught over 500 earwigs in one evening using his canola-oil trap!
Canola oil earwig trap. In one evening,
Dr. Cranshaw caught 535 earwigs!
If you're not into trapping, consider cleaning up around the house or in the vegetable garden where debris and mulch may be piled. Seal cracks near doors and windows. Insecticides can be applied as a barrier. For more information on European earwigs and the control options, refer to CSU Extension Fact Sheet #5.533.

Friday, August 1, 2014

Golf Course Wildlife

Tony Koski, Extension Turf Specialist

Those unfamiliar with golf courses (only a little over 9% of the U.S. population plays golf) often think of them as wildlife-unfriendly, chemical-laced, overwatered lawns. Nothing could be further from the truth. While some courses are more attractive to wildlife than others, every golf course can be a haven for birds, mammals, native pollinators, amphibians, reptiles and all other sorts of wildlife. The Audubon Cooperative Sanctuary Program for Golf program teaches member golf courses how to become more wildlife-friendly. You might be interested to know that 42 of Colorado's approximately 250 golf courses are Audubon Sanctuary courses.

Sandhill cranes at Ritz-Carlton Grande Lakes Club.
This last week Alison and I attended the American Society for Horticultural Sciences meeting in Orlando, where we were able to take a few "field trips" to area golf courses. While playing the Ritz-Carlton Grande Lakes Club (an Audubon Sanctuary course), we watched a flock of sandhill cranes feeding and playing in a sand bunker on the 18th hole following a thunderstorm. It's not easy to get so close to these beautiful birds.

Anhinga (water-turkey) at the Waldorf-Astoria Golf Club

 While playing the Waldorf-Astoria Golf Club, we found a very tame anhinga (commonly called the "water-turkey") sunning itself on a golf cart bridge. And I found this rather large snail alongside one of the tees.

Croquet ball-sized snail!
And while we never saw any alligators at any of the golf courses, we found this guy outside of our hotel, just across the street from the Orlando Convention center.

Monday, July 28, 2014

Into the Great Wide Open

Micaela Truslove
Broomfield County Extension

One of the amazing things about Colorado is its variable terrain, which encompasses several life zones from the grassy plains to the high alpine tundra. While many of our gardens are starting to wind down in the lower elevations, up high the flowers are in full bloom. Below are some photos taken from a recent hike along the 4th of July Trail to Diamond Lake in Boulder County. Hopefully this inspires you to get out and enjoy the height of wildflower season in the higher altitudes.

Common Name: Scentbottle
Scientific Name: Limnorchis dilatata
Look for this little beauty near water. These were located on along a hillside stream.

Common Name: Colorado Columbine
Scientific Name: Aquilegia coerulea
It isn't any wonder that this columbine was chosen as the state flower. "Columbine" is Latin for dove, a name chosen because of the graceful appearance of the flower. "Coerulea" refers to the blue color of the petals.

Common Name: Pink Pussytoes
Scientific Name: Antennaria rosea
Who can resist a plant with a name like "pussytoes"? As the name suggests, the blooms resemble the toes of a cat. Pussytoes can be found in local nurseries and, due to their mat-forming habit, make a wonderful groundcover.

Common Name: Monkshood
Scientific Name: Aconitum columbianum
The showy "hood" of this flower resembling a monk's cowl can be deep purple to blue to greenish white. Flowers are visited by hummingbirds, bumblebees and hawkmoths.
Common Name: Wooly Thistle, Mountain Thistle, Frosty Ball
Scientific Name: Cirsium scopulorum
Thistles have a bad reputation, but most of the thistles found in Colorado are natives and are an important source of pollen and nectar for native bees, they provide food for many species of butterflies, and thistle seeds are a favorite of finches and other birds. For more information about thistles in Colorado, check out Thistles of Colorado: Identification and Management Guide, which was produced by the Larimer County Weed District.

For more information on Colorado's wildflowers, check out the Colorado Plant Database or the CSU Extension Native Plant Master program. Happy wildflower viewing!

Thursday, July 24, 2014

A Darn Good Year for Fire Blight

Posted by: Alison O'Connor, Larimer County Extension

It seems that the summer of 2014 has been the "best year ever" for fire blight. I've never seen it so much and for awhile, our Extension Office phones were ringing off the hook about people seeing brown branches and crooked twigs from this bacterial disease. Fortunately CSU has a very good Fact Sheet on the subject.

If you haven't seen fire blight, it's characterized by the tip of the branch curling over, resembling a Shepard's crook:
The Shepard's crook of fire blight
If you look further down the branch, most of the leaves will be brown and you'll see a distinct darkening along the stem where the canker has infected tissues:
The bacteria turns the branch/stem a dark brown/black color
So what is fire blight? Well, as I mentioned, it's a bacterial infection caused by Erwinia amylovora that only occurs on plants in the Roseaceae family (apples, crabapples, mountain-ash, hawthorn, etc.). Remember, the Roseaceae family is one of the largest families in our landscapes, so it can affect a number of plants.

Infection can occur in a number of ways...through cracks in the bark or pores in leaves, on insect bodies, by splashing of the spores via rainfall or irrigation and through other natural openings. There seems to be a correlation between fire blight and hail-damaged trees from the previous summer. The bacteria kills cambial tissue (where the xylem and phloem are located) and continues to move down the branch.
Everything brown on this tree is fire blight
It's important to note that the tree will try to ward off the spread of the bacteria. Some species and cultivars are better at doing this than others. While a tree may be labeled as "resistant" to fire blight, it can still get the bacterial infection, but it's better at "sealing" off tissues to stop infection. The bacteria survives winter inside infected tissues and tends to ramp up during warm, wet springs. There is generally bacterial ooze associated with this disease.

So what can you do? Well, the best control is to plant resistant varieties. But that's easier said than done. You can prune out infected tissues during the growing season, but it's crucial that you sanitize your pruning tools between each and every cut. That means you have to spray them with Lysol or Listerine or dip them in a 10% bleach solution. Does this sound like a pain to you? It is. I've done it.

Or you can live with the ugliness of the tree this summer and prune out infected areas during the dormant season. By waiting, you don't have to sanitize. But you have to wait.

Regardless of when you prune, the current recommendation is to cut 8-12" below the edge of visible infection. This is a lot of extra branch you're taking off. And if the infection has moved into the main trunk of the tree, it's best to make a final pruning cut at the base.

For a personal anecdote, I was just at the Gardens on Spring Creek in Fort Collins. One of their apples was absolutely annihilated with fire blight. The director and the city forester were discussing the tree and they came to the conclusion to remove the tree. After making all the pruning cuts to remove the infected branches, the tree would have looked unsightly and wouldn't resemble the proper shape.

There are some pesticides that can be used, both as a dormant control and during flowering. The University of Minnesota Fact Sheet has information on the various types of pesticides that can be used to prevent new infections.

Tuesday, July 22, 2014

Weed of the Moment: Crabgrass and its look-alikes

By: Tony Koski, Turfgrass Specialist

Guess what? You might actually be seeing crabgrass in your lawn this time of year! It was late germinating this spring (we didn't see it in Fort Collins until late May), but now it's large and in charge. This is crabgrass in late May:
Young crabgrass
Now it looks like this (late July):
Small (smooth) crabgrass (Digitaria ischaemum)
Small (smooth) crabgrass--growing in concrete!
(That's a joke)
Small (smooth) crabgrass near sidewalk
Crabgrass seedhead
Many think they have crabgrass, but they don't. Here are some other crabgrass look-alikes that are often called crabgrass, but misidentified...

This is not crabgrass; this is bromegrass (wide, coarse blade; often a "W" watermark on upper tip of leaf):

Bromegrass in a bluegrass lawn
This is not crabgrass; this is annual bluegrass (characteristic apple green color; often with seedheads):
Annual bluegrass in a Kentucky bluegrass lawn
And this is not crabgrass; this is tall fescue (clumps of grass with rough edges on the leaf blade):
Tall fescue in a bluegrass lawn
 This isn't crabgrass either; this is orchardgrass (flat "stems" and tall white ligule):

The ligule is located like a collar on the inside of the leaf

Orchardgrass in the lawn
And no, this isn't crabgrass either; this is yellow foxtail (characteristic red base, yellow-y color):
Yellow foxtail, which can easily be confused with crabgrass.
The great news is that the same products that work on crabgrass
will work on foxtail.
Yellow foxtail--look at that distinctive red color!
Finally, this isn't crabgrass--this is bermudagrass (forms runners, invasive, pointy leaf tip):
Crabgrass is characterized by its prostrate growth habit, especially after mowing and a light, apple green leaf color. The seedheads are digitate (finger-like) and will begin forming in earnest in August. Crabgrass is a warm season grass (and a summer annual), so it will die with the first frost.

If you want to control it now, use any herbicide product containing quinclorac (such as Ortho Weed Be Gon Max Plus Crabgrass Control, Fertilome Weed Out Plus Q or Bayer All-in-One Lawn Weed and Crabgrass Killer). Be aware it may take more than one application to completely kill this persistent weed. It's much easier to control when it's a seedling or use preemergence products in early spring.

The big point to make, with the exception of foxtail and crabgrass, is that quinclorac will not work to selectively remove tall fescue, bermudagrass, bromegrass or annual blugrass from your lawn. So identification of grasses that LOOK like crabgrass is essential before you start spraying herbicides willy-nilly.