They're Baaaaaaack! Voles.

Posted by Alison O'Connor, Larimer County Extension

Well...to be honest...the voles may not be back so much as they never really left. We've blogged about voles before. Tony blogged about them in the lawn, and Irene blogged about them too--twice!

Meadow vole. Kinda cute, but crazy destructive.

Voles are small, mouse-like creatures with short, stubby tails. They are sometimes called meadow mice and we have eight (8!) species that live in Colorado. They are most active at night, but you will see them during the day--and like mice, they will run frantically when disturbed. You'll see damage in the lawn with their tunnels and also on landscape plants that they chew.

Vole tracks in the lawn.

The good news is that voles are a boom and bust species. We'll see huge populations one year, and the next season they will crash. Our state veterinarian once told me that some species of voles do their part to help control populations--male voles will become sterile when he has too many siblings. Fascinating.

They do have natural predators, like birds of prey, coyotes, and fox, but there seems to be so many voles and too few predators. Plus, voles love our landscapes where there aren't a lot of predators and it's a cozy, safe place to take residence. And that's where they are a problem. They like to live in tall grassy areas, and also in landscape beds--especially those with mulch and landscape fabric.

Voles love to live under landscape fabric, because it's safe from predators.

I visited a friend's landscape in Berthoud recently and over the winter, when voles were actively feeding on her plants, she ended up losing most of her roses, some lavender, and a few perennials. She literally just pulled the plants from the ground. Voles love to chew at the base of many ornamentals and fruit trees, girdling them. In the case of my friend, they chewed so much, the plants just broke off at the base.

All of her roses were killed this winter.

Girdled rose chewed by voles.

It's especially upsetting, since we all know that landscape plants are an investment. Losing this many can affect the budget--plus, the plants were mature and her landscape was beautiful last summer. The one that really got me was her fantastic dwarf blue spruce...which still looks perfectly healthy, but it's only a matter of time before it goes into decline. When you have the entire base of the tree that's been girdled, there's no way for the tree can move water and nutrients up and down the tree, since the xylem were damaged.

What looks like a perfectly healthy dwarf blue spruce...

The base of the spruce was girdled completely, approximately 2-3" off the ground.

Another sign of voles is damage to junipers. Voles love junipers--it must be their form of chocolate. I received an email earlier this week from a client who wanted to know what caused the browning in his junipers. I suspect it's voles and asked him for confirmation.

Potential vole damage in junipers.

Trace back the branches to the base and look for chewing where those branches attach to the shrub. The only remedy in this situation would be to individually (and painstakingly) cut out each damaged branch. Oh, and control the vole population.

What works best are unbaited mouse traps, placed end-to-end, near areas of activity and cover with a piece of gutter. Voles aren't smart animals and they will run, with free abandon, throughout the landscape. If you place the traps near active tunnels or near where they are actively feeding, you'll snap them, just like mice. Traps need to be checked and reset daily. There's lot of recommendations of baits that you can use (including Juicy Fruit gum!?!) but voles aren't motivated by baits--they are herbivores. Unbaited is best. They also don't seem to eat poison baits, which poses other potential issues for non-target animals.

Unbaited mouse traps, placed end-to-end, near active voles.

Cover the traps with a piece of gutter. Voles like the protection and shelter of above canopy, which is why they live under landscape fabric or in tall grass. They are less noticeable to predators.

Another tool that shows promise is using an organic fertilizer called Milorganite. This product has been around for decades and it's composted sewage sludge from the good people of Milwaukee, Wisconsin. (Don't worry--it's been heat-treated to 1600 degrees and poses no harm to humans.) Voles and other mammals, like rabbits, groundhogs, and even deer, don't like the smell.

Apply this fertilizer to any area of the landscape, including the lawn, landscape beds, or vegetable beds, at a rate of 15-20 pounds of product per 1,000 square feet. The 40 pound bag will cover about 2,000 square feet total and runs about $20. Now, this product is a repellent. It will make the voles go elsewhere, so using it in the entire landscape may not be practical, but focusing on active vole areas can work (or where you have rabbit damage). Once you apply the product, water it in. You'll notice the "earthy odor" for a day or so, but voles and rabbits will notice it for perhaps three weeks. Plan on applying it every month. It's not sold at most box stores, so check farm and ranch stores, or local hardware stores. As a side note, it's an excellent fertilizer, so you can use this to fertilize your lawn too.

Milorganite has been found to work to repel voles and rabbits in the landscape.

I should also point out that Extension doesn't usually list specific products, but Milorganite was tested in several research studies at the University of Nebraska, which is why we're recommending it. We'd love to hear if it works for you--be sure to let us know!

It's always something, isn't it? If it's not voles, it's late spring frosts. Or hail. Life as a gardener is truly a test of patience.

Junipers: Love 'em or hate 'em?

Posted by: Alison O'Connor, Larimer County Extension

Junipers. Every time you mention this plant, you get a variety of reactions--anything from the wrinkled nose to the nod of appreciation. Junipers seem to be one of those "love 'em or hate 'em" plants.

Junipers! Sited properly at Centerra Shopping Mall in Loveland.

For those who've heard me teach, I'm usually trash-talking these sturdy evergreen plants. But I recently had an epiphany: I don't actually hate junipers; I hate what people do to them.

Juniper "art"? (Photo by Eric Hammond)

I hate that people shear them within an inch of their life. I hate that people whack them back to keep them from growing on the sidewalk. I hate that people put them in the wrong spot and then torture the junipers (through pruning) to get them to behave.

Sheared. To death. (Photo by Deryn Davidson)

Stay off the lawn, juniper! (Photo by Eric Hammond)

Sited properly, junipers are, quite possibly, one of the most tolerant, drought-loving plants we have in the nursery trade. They come in a variety of shapes, sizes and colors and are one of the few plants that can actually fit into the "I have a 5-foot wide space but need a plant that grows 20 feet tall" request.

Did I really just defend junipers? Wow.

But really, junipers definitely have a place in the landscape, but it needs to be the right place. Sure, they collect trash and other debris and it's nearly impossible to remove grass growing through the foliage, and pruning them properly results in an itchy rash on the body, but they can look quite nice. And while they are a favorite of voles, they are a sturdy groundcover.

Junipers and all sorts of ugly. But a good plant choice for this location!

So give junipers a chance...a fighting chance. A legitimate chance to do good. And don't mistreat them or plan on shearing them. In their natural shape, junipers can be quite attractive. But when humans get involved, that's where things get ugly. What do you think? Did I convince any of you to appreciate this plant, even a little?

Keep ‘Em on the Up and Up Protecting Upright Evergreens from Snow-load Breakage.

By Curtis Utley, CSU Extension Agent, Jefferson County

Upright junipers. The center specimen has a co-dominant leader

Upright or fastigate evergreens are a common and attractive feature of many home landscapes often used as screen plantings or focal points in narrow planting beds. However, In Colorado, or any community frankly that experiences heavy snow fall in the winter, these narrow specimens can be damaged, disfigured or down-right destroyed by heavy snows.  Why does this occur?

Snow-load impacted Arborvitaes

Narrow tree forms succumb to snow load breakage because the side branches are poorly attached. The strongest branch attachment forms a 90 degree angle between branch and trunk (think of any native spruce or fir). When branches are attached more acutely there is

Right-angle branching

less trunk material to hold the branch into its socket. The likelihood of included bark forming between the trunk and a branch increases if a branch immediately ascends from the tree’s trunk. The other reason Fastigate cultivars often break in snow load events is our fault in how the trees are pruned and managed. Most narrow cultivars are sheared to keep their appearance balanced and tidy. If the terminal branchlette is clipped and apical dominance is removed, aggressive, competing side branches will try to grow up and become the leader.

Strong central leader

If these competing side branches are maintained they will grow into co-dominate leaders that will have included bark in the future and may break in future snowstorms.

Co-dominant leaders failing after heavy snow load

So what should you do to protect your fastigate trees in the winter?

Wrap them with Ag fleece.

Ag Fleece protects shrubs from snow-load and desiccation

1. Wrap them with straps

Wide strap wrapped around a Woodward juniper

Light cord or Christmas lights can prevent snow load breakage 

2. Wrap them with Christmas lights or light cord

3. Stake them when small and tie them loosely to the stakes

Multi-Site Woody Plant Trial 2006 Planting: Woodward Columnar Juniper

A mature Woodward juniper at the Colorado State University Arboretum 

The Colorado Multi-Site Trial of Woody Plants evaluates the suitability of “new” and underused woody plants across the various climates of the Colorado.  For more information about the trial and test sites see this previous post.  

The 2006 planting of the trial contained a number of interesting plants.  Some of which were very successful  and some which struggled or failed to survive.

The 2006 planting at Harding's Nursery outside of Colorado Springs

2006 Planting:

·       Acer monspessulanum (Montpelier maple)

·       Juniperus scopulorum ‘Woodward’ (Woodward columnar juniper)

·       Larix decidua (European larch)

·       Prunus serrotina (Black cherry)

·       Pyrus ussuriensis ‘Burgundy’ (‘Burgundy’ ussurian pear)

·       Quercus polymorpha (Monterey oak, Netleaf white oak)

·       Quercus undulate (Wavy leaf oak)

One of the plants which is particularly promising based on its performance during the five year trial period is the Woodward columnar juniper.   I know using the word “promising” in the same sentence as “juniper” has caused me to lose credibility with a significant portion of those reading this but hear me out; this is a really worthy plant.  Woodward performed well in the trial and consistently demonstrated both adaptability to our climate and ornamental features which would make it an asset in a variety of landscapes.

Woodward columnar juniper in Fort Collins in the spring of 2016. 

 Woodward was “rediscovered” by Front Range horticulturalists growing at the then defunct Cheyenne Horticultural Field Station.   It is a cultivar of Rocky Mountain juniper selected for its upright habit and strong apical dominance.  As a species, Rocky Mountain juniper (Juniperus scopulorum) is valued as a reliably cold hardy (Zone 3) and drought tolerant conifer.  This bore out with Woodward in the trial.   Across all the sites only a handful of plants did not survive the five year trial.  We observed little winter desiccation, wind burn or pest issues on any of the trial plants.  It is even more notable that we did not observe any damage from snow loading as such damage often plagues woody plants with upright habits.   This may be due to Woodward’s relatively small and shorter lateral branches and strong apical dominance.  The trial plants retained their narrow form and were remarkably consistent in their width across all five planting sites.   More than all this, they were attractive. They had a soft blueish green needle color and a “stately” form.

  

Mean width data for Juniperus scopulorum 'Woodward' the trial five sites.

Based on the data from the trial it appears Woodward columnar juniper is a tough plant which can be grow successful throughout the state.  Its well suited for small landscapes or tight spaces and could be used as a screen or even as an interesting specimen.  It was promoted by Plant Select in 2015 and was in high demand.  So, if you are interested in planting one get to the nursery early next year!    

Woodward juniper in Orchard Mesa in 2010

Holiday Decor: Hortie Style

Posted by: Alison O'Connor, Larimer County Extension

For some people, they jump into the holiday season head-first and excited; I tend to warm more slowly to the hustle and bustle of December. But after taking a wreath making workshop at the Gardens on Spring Creek (once again taught by the incredible Nancy Frank), I caught the bug. Perhaps it was the scent of fresh greens in the air...

Holiday "wow" on your doorstep.

Making wreaths is a fairly easy task, but even more "SHAZAM!" is taking ordinary evergreens from around the yard and (literally) shoving them into foam in an urn to make a fantastic welcome to your front doorstep. It's a snap and anyone can do it! It will take you about 30 minutes.

Here's what you need:

• Container (use your favorite from the summer!)
• Styrofoam block (can be purchased at any craft store)
• Evergreens (from the landscape or purchased from a florist)
• An inexpensive pre-made wreath (or make your own)
• Various embellishments for color and pizzazz (from the garden or the craft store)
• Big ol' fancy bow

First, find your container. I used a plastic urn. If you use one that is ceramic or clay, be sure that it won't crack in cold weather. Because the arrangement will be top heavy, fill the lower half of the container with bricks or rock to weigh it down.

Add weight to the bottom of your container so it doesn't tip over!

Then place your foam block on top of the bricks. Make sure it's fairly level. If you feel it may not be sturdy, you can tape it down, but limit how much surface area you cover with the tape (it's hard to poke branches through tape). Because my block was fairly large, I had to shave down the corners to fit our pre-made wreath on top....

Foam block from the craft store. You may have to shave down the sides to fit the wreath on top.

To help cover the container edges, place an inexpensive wreath on top and make sure there is foam showing through the wreath's center. Now, if you don't want to buy a wreath, you can make one. Or be sure to use greens to cover the container edges. But the pre-made wreath is really a time saver! The diameter of your container will determine how large a wreath you need.

Lay the wreath on top of the container and make sure foam is showing in the middle.

It's important to decide how the arrangement will be viewed. Mine is against a wall, so I didn't need to worry too much about making sure the back was attractive. But you do need to "even it out". From the greens you've cut or purchased (or asked nicely for at tree lots), cut a few longer pieces for the back of the arrangement and shove them into the foam. Don't be shy! Push hard to make sure they stay in place.

Start framing your arrangement with longer pieces.

I used common greens from the Colorado landscape. And (gasp!) junipers look fantastic in these arrangements. If you can find them with cones (berries), even better. Maybe junipers really do have a purpose?!? Anyway, I cut junipers, spruce, Scotch pine, Austrian pine and some ornamental grass plumes.

From front to back: junipers, Scotch pine, spruce, ornamental grass plumes and Austrian pine.

After you get your back pieces placed, just keep cutting and adding. Be sure to leave a longer stem so that it's easier to push it into the foam.

A nice long stem to poke into the foam.

Add more greens...

Keep greening away!

And more greens...until you're happy with how it looks. It's all a matter of what you like. It can be really full and bushy or a little more sparse. Just make sure you can't see any foam when you're finished.

The blue junipers really add a little somethin' somethin', don't they?

Once your greens are finished, then add other fun adornments, like ornamental grass plumes, berries, pinecones, sparkly dazzle or whatever moves you. In terms of berries, I'm not sure there is anything in our landscapes that will stand up to December weather, so I always buy the fake cherry red ones at the craft store. But you can absolutely do a natural arrangement.

Ornamental grass plumes from Miscanthus and pampas grass.

Then add your bow (mine, of course, is sparkly!) and move the container to your front step for everyone to "ooh" and "aah". You could consider spraying it with an anti-desiccant, but that's optional. So are posing your beagles :)

Happy Holidays from Hazel and Maple!

When Junipers Go Bad...

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

...it's generally not their fault!  But how many times have you seen poor defenseless junipers pruned into shapes like this? (Please note that I am not a fan of junipers in the landscape, but this is just ghastly....and really funny!)  I took this picture on my way to Fort Collins this morning...a route I drive nearly every day.  I was shocked that I hadn't seen it before now.  So like any good plant dork, I pulled over to take a photo.  I'm guessing one of two things:
1. The company (who shall remain nameless) wanted a pineapple-like shrub to welcome clientele.
2. The person responsible for pruning couldn't reach the top.

What do you think?  Anyone else have pictures of plants that have been pruned, um...artfully?