CO-Horts Blog

Thursday, September 29, 2022

A Transplant Success Story

A transplant success story

A way to improve transplant success? Yes please! 

Silverton bluemat penstemon
By Cassey Anderson, Adams County Extension Horticulture.

As gardeners I believe we’re all endless optimists, maybe hoarders? Perhaps that’s just me! This means that we may purchase plants at times of the year that are not ideal, but who can pass up a sale or when we find a plant that's been on our list for ages? We then suddenly need to get them in the ground. For our Colorado Master Gardener Xeriscape Demonstration garden in Adams County we got a bunch of plants in June, and then again in August this year and wanted to ensure their success. 

Over the last few years one of our CMGs began experimenting with providing shade for new transplants and we’ve had an incredibly good success rate. The first year we only lost one plant, this year we have only lost two. In previous years before we began shading we lost far more. We’re hoping to start tracking more carefully in future so we could tell a more precise story, but alas have not thus far.

Pinetip Penstemon enjoying morning sun

The process we now use is simple, take a small piece of shade cloth (in our case it was a piece of the large sailcloth shades that go over decks and the like), prop it up to provide afternoon and evening protection. We left the shades up for about a month to ensure establishment. We do also practice root washing to the best of our ability (especially for plants with larger root systems, for those with less roots we knock as much potting soil off as possible). These systems prove remarkably resilient in wind and rainstorms so no real adjustment is necessary until it comes time to take the covers away. 

For smaller plants we used old plant stakes that had lost their tags with clothespins to hold the cloth onto the stakes. For larger plants such as the wax currant (below) we planted this year we used a tomato cage as a support for the shade cloth. Since this plant came with some scorch already happening, we surrounded it completely with shade cloth. Many of those original leaves have dropped but new ones have replaced them.

Wax currant came with scorch so
we took extra precautions. 

One side advantage of shading the plants as they establish has been that the soil stays a little moist for longer, particularly beneficial in our xeric garden that typically only gets watered once a week. That said, we do also provide supplemental water a few times a week in the first few months for our newly establishing plants. This is also a great way to mark new plants so that volunteers don't accidentally weed them out, and it's easier to find them for watering. 

Hopefully you can enact similar successes in your own landscapes! 

Tuesday, September 27, 2022

May The Gourds Be With You

Posted by Donnetta Wilhelm, Arapahoe County Master Gardener

The Cucurbitaceae family of plants features about 975 species of food and ornamental plants, which includes cucumbers, gourds, melons, squashes, and pumpkins. It is one of the largest plant families used as food for human consumption. Three standouts of this plant family: it boasts some of the biggest fruits and vegetables in world, the plants have many interesting characteristics, and this plant family offers a variety of uses other than just human consumption.

Grow Big

The Guinness Book of World Records lists the largest pumpkin in the world weighed just above 2,702 pounds in Italy in 2021. The longest bottle gourd, known as calabash, measured 12.5 feet long in Canada in 2015. The longest cucumber on record is 42.1 inches in 2011 in the United Kingdom. Not to be outdone by other countries, the heaviest butternut squash weighed 65.5 pounds in 2021 in Rhode Island.

Interesting Characteristics

Cucurbitaceae plants are monoecious, meaning they have both separate male and female flowers. While only the female flowers produce fruit, they need the male flowers to accomplish this task. Plants in this family are mostly prostrate or herbaceous annuals and are native to the tropics and subtropic regions. When grown in Colorado, they are warm weather lovers, need full sun, and for best production, plenty of water as the fruits begin to develop.

A squash bee (Peponapis spp.). Photo: Susan Ellis,

Bumblebees and squash bees (Peponapis spp. and Xenoglossa spp.) are the best pollinators of pumpkins and squash since they forage in the morning. Squash bees have a life cycle that is perfectly timed with the life cycles of cucurbits. These bees have very fuzzy bodies that accumulate substantial amounts of pollen.

Three genera, Cucumis spp. (cucumbers, melons), Cucurbita spp. (pumpkins, squash), and Citrullus spp. (watermelons), rank among the top 10 in economic importance among the edible crops of the world.

An interesting fact about cucumbers is that because they have seeds in the middle and grow from the flower of a cucumber plant, they are botanically a fruit. Watermelon is considered the most popular among the cucurbits whose delicious fruit are widely consumed throughout the world. The red pigment of watermelon is the antioxidant lycopene, and watermelon has more lycopene than tomato.

Cucurbits are rich in carotenoids, terpenoids, saponins, and phytochemicals. Fruits, vegetables, and edible seeds from the Cucurbitaceae family have a positive influence on human health. Various studies have shown the plants in this family have antioxidant, antidiabetic, anti-inflammatory, and cleansing properties, and the seeds and oils have high nutritional value.


Cucurbitaceae is one of the most varied and widely used plant families. The cucumber is mostly used as a consumption crop, used in soups, sandwiches, drinks, dips, and a variety of pickling. But cucumbers are also used in a wide range of hair, skin, and beauty products. Muskmelon and watermelon are used fresh in desserts, and alone or in combination with other fruits in salads. Watermelon rind is commonly pickled. In Russia, beer is produced from watermelon juice. Pumpkin and squash are cooked with other vegetables or used in pie-making, cookies, breads, and roasted seeds.

Squash blossoms are edible and can be stuffed with a variety of ingredients. Photo: Canva

Luffa, bottle gourd, ash gourd, bitter gourd, pointed gourd, and Indian squash are cooked, and some are fried for the preparation of various dishes. Blossoms of squash, pumpkin, and ash gourd are consumed as edible flowers stuffed with a variety of delectable cheeses, herbs, rice, mushrooms, and crabmeat. Hundreds of recipes can also be found for the use of pumpkin leaves.

Gourds are not only used for food, but for making musical instruments, containers, and other decorative pieces. The Lagenaria siceraria (bottle gourd) is commonly used for anything from bowls to musical instruments to smoking pipes. They are the preferred water vessel containers in many parts of the world because they are lighter than earthenware jars. Luffa cylindrica (sponge gourd) is used as loofah, sponges and scrubbers, and even as filters, while Sicana odorifera (casabanana or musk cucumber) is often used as an air freshener as the ripe fruits produce a long-lasting, fruity fragrance. Siraitia grosvenorii (monkfruit) is used as a sweetener, 300 times sweeter than sugar and lower in calories.

Many different gourds found in Africa and India are used to make musical instruments such as drums, lutes, and sitars. Shaker gourds are probably one of the earliest of all musical instruments, and the Cucurbita palamta (coyote melon) is used to create maracas.

Jack-o'-lanterns. Photo: Pixabay

When Irish immigrants moved to the United States, they brought with them the myth of “Stingy Jack.” Rather than carving turnips like in Ireland, they began using the locally grown pumpkins for carving. The Jack-o’-lantern variety of pumpkins have a thinner shell and less flesh for better carving.

Western culture esteems ornamental gourds for autumn decorations inside and outside the home, special occasion accents, and birdhouses.

Whether trying to grow the world’s largest zucchini, pumpkins for the World Championship Punkin Chunkin competition, cucumbers for grandma’s favorite pickling recipe, or the beautiful ornamental gourds for autumn or holiday d├ęcor, there is a Cucurbitaceae perfect for your garden.

Tuesday, September 20, 2022

Preparing Your Home for Wildfire

 By Mark J. Platten, CSU Extension Director, Teller County

As we've seen with the Marshall Fire, Black Forest Fire, and Waldo Canyon Fire, wildfires can affect urban environments as well as the more rural, forested environments we associate with wildfires. In this blog we'll discuss strategies that can give you the highest likelihood of having your home survive a wildfire, although there are no guarantees.

Defensible Space

Mountain Shadows (Waldo Canyon Fire, June 23, 2012)

Defensible space is the buffer you create between a building on your property and the grass, trees, shrubs, or any wildland area that surround it. This space is needed to slow or stop the spread of wildfire and it helps protect your home from catching fire—either from embers, direct flame contact or radiant heat. Proper defensible space also provides firefighters a safe area to work in, to defend your home. 

It is NOT a guarantee that firefighters will be able to save your house during a wildfire.

Fire Behavior Triangle

Three factors determine wildfire behavior: fuels, weather and topography.

         We cannot alter weather or topography, so we must concentrate on altering fuels.


Home Ignition Zone (HIZ)

Two factors have emerged as the primary determinants of a home’s ability to survive a wildfire:

1. The quality of the defensible space and,

2. A structure’s ignitability.

         The primary goal is to reduce or eliminates fuels and ignition sources within the HIZ.

Building Envelope


The likelihood your home will survive a wildfire is based largely on how your home is built and what materials are used. 


Install or replace your roof with a Class A-rated roof with noncombustible coverings.

Clay and concrete tile are noncombustible and because of their relatively large thermal mass, retard the transfer of heat

Metal shingles and panels are noncombustible, but they readily transfer heat. If they are installed over wood battens, fire-retardant-treated battens should be specified and installed. 


An open overhang. The exposed timber rafters and decking are susceptible to ignition, and embers and hot gases can enter the attic through unprotected vent.


Remove all debris from the roof and gutters to prevent embers from starting a fire. 

Make sure to remove branches that overhang the house.


Exterior wall coverings that are noncombustible or fire-resistant and not susceptible to melting are recommended. 

A minimum fire-resistance rating of one hour.

For the best protection, ensure that exterior wall coverings are noncombustible or fire-resistant and not susceptible to melting.

Concrete, fiber-cement panels or siding, exterior fire-retardant treated wood siding or panels, stucco, masonry, and metal are recommended materials.


Cover exterior attic vents, dryer vents, and under-eave vents with metal wire mesh no larger than 1/8 inch to keep embers out.


Exterior doors are subject to the same types of exposure as exterior walls in a wildfire.


Garage doors are typically made of wood, aluminum, or steel and are insulated or non-insulated.

         The common split-rail or picket fence can become fuel for a wildfire, especially when the fence is old and weather-beaten.

This type of fence can also collect embers and firebrands in a wildfire and act as a horizontal ladder fuel by allowing the fire to travel along the fence toward the main building.


Replace combustible materials with noncombustible or fire-resistant materials.Replace timber railings with railings constructed of fire-resistant materials.

Construct deck skirting around the deck or max 1/8-inch wire mesh.

Don't store combustible items on the deck.  



Double-pane, tempered glass is best.

Install metal screens on all windows.

Plastic skylights can melt.




These are recommendations to give your home the best chance of surviving a wildfire.

Fall Heroics: Or, How My Garage Became Filled with Plants

Posted by: John Murgel, Horticulture and Natural Resources Educator, Douglas County 

 Across much of the state, fall is in the air. First frosts have come and gone in the mountains; here on the Front Range we have a few weeks left before our average “end of tender annuals.” I am content to let most of these flashy fillers die, but some, like succulents, semi-hardy trees or shrubs, and tender bulbs and tubers are worth the effort to try to preserve year after year. These are plants which improve with size—becoming truly show-stopping only after years of cultivation. Who hasn’t admired an enormous Colocasia, prize Dahlia, or bulging Aloe? The only trick is that unlike gardeners in more temperate climes, you will have to invest some energy in keeping such plants alive to impress again next year. 

 With the exception of true tropical plants, many bulbs and tender plants used as annuals in Colorado still require a cool dormancy—a winter of sorts. Just not a Colorado winter. So the trick to keeping them for use next year is to provide the conditions of a dormant season from their native range—sometimes this is cool and damp, sometimes cool and dry, and sometimes merely dry. 
Pink Geranium maderense flowers
Geranium maderense will only flower after a "cool" winter.

 The first step is to evaluate what plants will require extra effort to be saved. Anything in a container is a must—the exposure above ground is too much for even some normally hardy plants. Tender plants and bulbs tucked into in-ground beds will likely require digging, but a plant that is at the edge of its hardiness might surprise you in the right microclimate—some Dahlias planted deeply and tucked against the foundation on the south side of the house, for example, might pull through. Without microclimate magic, though, and for real treasures, moving to storage is safer! For bulbs and tubers, dig after the tops of the plants have been killed by frost. Be extremely careful to avoid damaging the storage organ in the process; any wound is a site for decay to develop. Clean off excess soil and dry them in the shade (or indoors) for a few days to allow them to cure. Then it is time for storage. For successful winter storage, aim for 35 - 50 degrees F. If you have root cellar, they were designed for this. Garages that stay above freezing work, and even a refrigerator can work too (agreeing my wife and children on the exact ratio of ornamental plants to actual food at my house is a work in progress). Bulbs and tubers need to be kept from drying out; it seems that nearly as many techniques for this exist as gardeners. Commonly, things like Dahlias, Colocasias, and Caladiums are stored in plastic bins, loosely packed in a dampened medium, like sawdust, shavings, or even shredded paper. Check on them a couple of times a month and remove any that are beginning to rot. Keep them in the dark (remember that we’re pretending they’re in their natural habitat, underground) to prevent them from sprouting in storage. 
dahlia flower

 Succulent plants, in contrast to bulbs and tubers, need to be stored somewhere where they will get ample light. My garage is perfect for this, as it has a convenient window. The cooler your storage location for most succulents, the more important it is that they stay absolutely dry through the winter. Wet roots will translate easily into rot if it’s cool. If you need to disassemble a container for storage or plan on dividing any succulents, make sure to do it before it becomes too cool in your storage area, or keep the plants someplace warm for a while before moving them to their overwintering location—they need time to heal any root damage from re-potting to help defend against rot. "Curing" the plants out of soil for a couple of days can be very helpful too. Don’t overwater them! 

container of mixed succulents for dividing
Time to divide this container's contents!

 Keep a careful eye out for pests through the winter, particularly aphids. If any come into storage with the plants, their population can grow quickly in the absence of natural enemies. Scout your plants frequently and deal with any pests you find—early action will save you a lot of pain and heartache later in the winter. When summer returns and nighttime temperatures are above freezing, plants can be returned to their outdoor displays. For plants in the ground, be sure not to plant them in too-cold soil, as this can rot them right at the finish line! For succulents or tender plants, be sure to gradually acclimate them to direct sunlight. Just thinking about all that makes part of me want just to let all those darn plants freeze this year. But I know I’ll relent. I have an Aloe vera that badly needs dividing, and aloe divisions make great Christmas gifts!

Tuesday, September 13, 2022

Exploring Ironton Park Fen

 by Yvette Henson, San Miguel Basin CSU Extension 

Yesterday, I participated in a class sponsored by Great Old Broads for Wilderness in the Northern San Juan Region.  (To learn more: )  We explored a fen in the Ironton Park area on Red Mountain pass in Ouray county.  The class was led by Peggy Lyons, retired botanist for the Colorado Natural Heritage Program in Western Colorado.  She is an expert in native plants of the San Juan mountains.

Peggy Lyons, botanist and fen class leader
(photo shared with permission)

A fen is a peat-accumulating wetland fed by ground water (as opposed to a bog which is fed by surface water).  It takes thousands of years for fens to form. Fens are formed by and need year-round inflow of water, cold temperatures, and stable site conditions to remain.  The perpetually saturated soils of fens create aerobic conditions which slow decomposition and allow organic matter to accumulate.   To be classified as a fen, the organic soil layer must be at least 16” deep.

Fens are great carbon sinks.  They also slow runoff, which helps reduce flooding; the plants in fens filter pollutants, improving water quality; and they provide habitat for plants and animals, unique to that habitat.

A moose family that was seen yesterday just across the highway. 
Moose habitat is wetland, including fens.

The fen we explored was an iron fen.  Iron fens are a special type of fen that occur on iron-rich soils and are unique to Colorado.  The water that flows through the fens is very acidic (with a pH less than 4.5).

A view of Ironton Park Fen, looking North towards Ouray.

The vegetation in fens is very different from surrounding ecosystems.  In iron fens, with acidic soils, vegetation is primarily sedges, rushes, sphagnum mosses and specialized shrubs.  The plants that were new to me were Bog birch and sphagnum moss. 

bog birch, Betula glandulosa

sphagnum moss, Sparganium angustifolium syn. Sphagnum angustifolium

One of the class participants was retired from United States Geological Service and she told us about ferricrete, a stratified rock deposit in the San Juan region that indicates the existence of iron fens thousands of years ago.

ferricrete sedimentary deposit in the hillside above our fen,
indicating their was a fen there thousands of years ago

close up of a piece of ferricrete

What a lovely and informative day I had in the mountains I love.  It was good to see Peggy Lyons and meet new like-minded people.

Most of the participants in the Ironton Park fen class
(photo shared with permission)



Thursday, September 8, 2022

You may not believe it, but cold IS coming

Posted by Todd Hagenbuch, Routt County CSU Extension

This week’s record temps may have us all lulled into a false sense that summer is here to stay, but if you’ve lived in Colorado for any length of time, you know that a frost is just around the corner…at any time! In the high mountain valleys of Northwest Colorado, we’ve typically had a scare with frost by now and are ready to get our gardens through a cool night. I think this Saturday might be my zucchini's closest brush with death this season with a projected low of 37 in Phippsburg…which usually translates to 5 degrees cooler at my house. So what will we do to get through the night in order to keep things going for another week or two?

Plants are all snug under sheets and tarps, plus old-
fashioned holiday lights provide extra heat.
Simple cloth covers like old bed sheets or floating row covers go a long way towards protecting sensitive plants when the temps are just at or near freezing. On Saturday, we’ll likely cover the summer squash, beans, and potatoes with old sheets that we have procured over the years from the local Phippsburg Community Club Rummage Shop. This simple layer of protection will be all those plants need when temps get down to even 30 degrees, and hardier plants like the cabbage and peas will be fine and cruise through the night without issue.

If it looks like it’s going to get even colder, then more extreme measures need to be taken. We have metal hoops to put over our plants so heavier materials don’t need to lay on top of them. We can spread the sheets or blankets over the hoops and trap the heat coming off of the soil to ensure plants remain in temps well-above freezing.

When one of those really cold snaps hits and we know we’re going to have another stretch of warm temps ahead, we go all-out to ensure we get our plants through the worst in order to get another week or two of growth out of them. Using the hoops with sheets and blankets to hold heat, we also cover the top with plastic so if it’s a wet storm that’s bringing the cold, the water is shed and doesn’t further weigh down the insulative layer.

If the soil isn’t warm enough to provide the warmth needed, we go a step further and pull out the old C-7 and C-9 holiday lights and string throughout the garden to increase the temps a few more degrees under the covers. Those old lights are super inefficient for holiday lighting when compared to the newer LED types, but that inefficiency means they are awesome heat producers. Take a look at the temperature difference between the space under the covers with the lights and outside- what a difference!

WOW- a 20 degree difference under the covers!
If you think a cold night is coming but that several growing days still exist in your plant’s future, take a little time to cover your garden so they can keep producing. Heck, I know your neighbor needs another zucchini even if they tell you they don’t!

For more information on how to protect your plants during a cold-snap, visit the CMG Garden Notes on the subject at

Wednesday, September 7, 2022

The drawbacks of converting to an all-gravel yard


Irene Shonle, Horticulture Agent, El Paso County

As both water prices and the average summer temperatures rise, many people are reconsidering their lawns.  At first blush, replacing your entire yard with landscape fabric covered with gravel can seem like a good solution- it seems both low maintenance and a way to save on your water bill. In fact, the all-gravel yard is sometimes touted as a ‘xeriscape’ yard- but really, it’s a “zero-scape” yard, and it may not be the solution you are looking for.

First, it’s not as maintenance-free as it may seem.  It can look pristine when first installed, but over time dirt will settle into the pores in the gravel, creating an ideal bed for weed seeds to blow in and germinate. These weeds are hard to pull, because their roots can go down into the fabric.  Because they are hard to pull (and even harder to hoe), this usually means committing to a yearly round (or two) of  herbicide treatment. Additionally, the gravel can shift over time, especially on slopes, exposing the landscape fabric which often frays and tatters. It can be also be difficult to remove leaves and other debris that blow onto the gravel.

Weeds growing in landscape fabric/gravel
Landscape fabric showing through the gravel


Landscape fabrics restrict water and air movement, reducing soil microbial health, and potentially affecting any remaining landscape plants. Over time, landscape fabric pores will trap dirt and other sediments, making them even less permeable. Poor permeability can contribute to excessive run-off in rainstorms.

If you rock your yard, but still have trees and shrubs, be aware that you may need to provide supplemental irrigation. Trees often derive much of their water needs from lawn watering – if no alternative water source is supplied to make up for that, the trees will suffer and potentially die.

All-rock yards also contribute to the urban heat island effect more than lawns because there is no evapotranspiration from the living plants.  Imagine how hot an entire neighborhood would get if all the front yards were rocked in. Imagine how such a place might feel industrial and a bit on the depressing side, rather than a welcoming place to live for people, birds and butterflies.

Another disadvantage is that rock mulch can be difficult to remove if you change your mind (or the next person who buys your house). The gravel is easier to install than to rake up and haul away.

As an alternative to rock, consider replacing your lawn with either a low-water turf alternative such as buffalo grass, or with low-water native plants that support pollinators and birds and increase curb appeal. 

Native plant xeriscape

Thursday, September 1, 2022

Test, Don't Guess!!!


Welcome back to another edition of: “Who Wants to be a Plant Diagnostician?” with your hosts, the Jefferson County Plant Diagnostic Clinic. This week, we wanted to focus on the mantra, “Test, Don’t Guess!”, as it applies to plant diagnostics. In the world of plants, there are many pathologies that present similarly, so it’s critical to thoroughly evaluate the problem at hand and the possible causes in order to best create a management plan. Below, we’ve put together a few examples of some lookalikes that have recently come into our clinic…

Test, Don’t Guess!


When you hear the words “spots” and “tomatoes” in the same sentence, you may automatically assume tomato spotted wilt virus (TSWV), a virus vectored by adult thrips. And in some cases, you may be correct. For example, we received a recent inquiry regarding tomatoes presenting with chlorotic rings (shown below), a classic indicator of TSWV:

Tomatoes believed to have tomato spotted wilt virus (TSWV).

However, this assumption does not always hold up. In another recent tomato inquiry, we received photos of tomatoes that also have yellow spots (shown below); these spots, we think, are caused by stink bug feeding. Stink bugs typically feed on green fruit and produce dark pinpricks, surrounded by white tissue. However, as the fruit ripens, these damaged areas turn yellow.

Tomatoes with spots believed to be from stinkbug feeding. 

We say “we believe” the first example of tomatoes has TSWV and the second example was fed on by stink bugs because we haven’t received physical samples to the clinic yet. These are our initial suspicions and, to confirm, we need to TEST! To differentiate between TSWV and stink bug feeding, we would first evaluate the plant for other symptoms. TSWV may result in bronzing leaves, leaves with small, dark spots, tip dieback, streaked terminal stems, or drooping leaves. Conversely, stink bug damage should be confined to the fruit itself. At the end of the day, symptoms may be variable for TSWV though, so, fortunately, we have a great tool at our clinic to rule-out TSWV: a TSWV antibody test! As TSWV and stink bugs have very different implications for management and the fate of the plants, TESTING, and not GUESSING, is key!


Switching over now to woody plants, we received an inquiry regarding spruce trees that were experiencing browning/purpling of needles (see below) and extensive interior needle drop. Due to the cultural characteristics of the affected trees (very mature, very closely-spaced together, located near greater exposure to temperature extremes and winds, etc.) and the purpling of the needles, we felt confident that the trees were experiencing a cycle of high competition for water, drought stress, and winter dessication. However, due to the browning of the needles, needle shedding, and dark banding observed on some needles (see second image below), there was concern regarding fungal colonization of the spruce (i.e. needle cast fungi).

Discoloration and dark bands found on spruce, likely due to water stress and winter desiccation.

Although needle cast diseases are rarely found in dry environments, we made sure to TEST, not GUESS! Roughly one week after plating a number of suspicious areas of needle discoloration onto growth media, we had several different-looking fungal growths on our plates! In examining these various fungal growths under the microscope, we found no evidence of needle cast fungi; rather, we saw several types of saprophytic fungi (see example below) that are typically found in our environment and would not cause damage to spruce. Better to be safe than sorry!

Hyphae of saprophytic fungi (consistent with Alternaria/Ulocladium).


Our last example of the day deals with another woody plant: the Austrian pine. We’ve had a handful of individuals bring samples into the clinic lately, all highly concerned about Pine Wilt/Pinewood Nematode (PWN). The trees generally present with needle discoloration and rapid dieback or death of the tree, which is consistent with PWN. Additionally, some of the samples reveal bluestain fungus in the wood (shown below), which is another indicator of PWN. However, none of these symptoms are conclusive of PWN, so we always have guessed it...test, not guess!

Blue stain found on Austrian pine.

Further examination of the specific sample shown above revealed exit holes, galleries, and Ips pini beetles (see below). Egg galleries of Ips are usually Y- or H-shaped; upon hatching, larvae create smaller lateral galleries from the main gallery. Due to Ips tunneling, affected parts of the tree discolor and die, consistent with the symptoms of our samples. However, Ips typically attack already stressed and weakened trees, so while we have clear evidence of Ips, we can’t rule out PWN without a further test! 

Exit holes (top-right of top image) and galleries/frass (both images) made by Ips pini, found in Austrian pine.

By running a PWN-specific test, we can extract and identify the nematodes responsible for Pine Wilt Disease, if present. Most of our samples came back negative for PWN; however, we did find a few nematodes in the sample (shown below)! BUT, they don’t have the same physical features as PWN…so, on to another test: we’re working through the identification of these nematodes to identify whether they are the Pine Wilt Nematode, Bursephalenchus xylophilus, or one of the many non-pathogenic nematodes that live in and around the tree.

Our unidentified nematode, approximately 300-350 microns in length.

This is an adult, male Pine Wilt Nematode; length approximately 1000 microns. Photo Credit: Pest and Diseases Image Library,

And that concludes today's edition of "Who Wants to be a Plant Diagnostician"! While I've most certainly overused this phrase throughout the course of this blogpost, I'm going to reiterate it one more time...TEST, DON'T GUESS!!!