The Honeylocust Arch-Memesis...Thyronectria!

How to prevent and control Thyronectria

By Chris Leinster - August 22, 2026

The Honeylocust Arch-Memesis...Thyronectria!
Honeylocust are among the most popular shade trees sold in Colorado. They perform well in our climate, are relatively clean, and they grow quickly. Majestic Honeylocust line the streets of Denver where their over-arching branches form a canopy over our most historic avenues. Their tiny leaves allow a fair amount of light to penetrate through their foliage, so they keep the area underneath them bright while their cooling shade offers a refreshing respite. They are ideal for uplighting, as the light penetrates high up into the crown and softly reflects a warm glow back to your patio or entryway. The leaves are so small that they sort of shrivel up and mulch into your lawn or garden beds and really don’t require raking.

Unfortunately, Honeylocust harbor an arch-nemesis…the fungal infection Thyronectria. Thyronectria is an airborne fungus that enters the enters the Honeylocust (and sometimes Coffeetree) trees through wounds or cracks in the bark. It can also spread from tree to tree through interconnected root systems. Once infected, the fungus feeds on the tissue of the trees leaving soft spots, or cankers, that weaken the trees and disrupt the flow of water and nutrients through the vascular system of the trees’ trunks and branches. Drought stricken, nutrient deficient, stressed, or otherwise unhealthy trees are unable to fend off the disease. Without intervention and proper care, the fungus slowly consumes the tree until it eventually dies.

Fortunately, healthy Honeylocust are quite adept at combating the fungus and have the ability to resist and recover from minor infections. Just as humans have an immune system, trees also respond to interloper organisms by initiating chemical and hormonal defenses. The sap you may see oozing from open infections is actually the tree attempting to flush the fungus from it’s tissue.

Ryan Bartlett, a colleague and lead instructor for the Arborist Apprenticeship Program at Front Range Community College and owner of Sanctuary Tree PHC, likens Thyronectria to the common cold. He says “it’s ever-present…just don’t let it turn into pneumonia. If the tree looks vital (good canopy, good water, etc…), then it’s just a runny nose and will get better.” Healthy people who exercise regularly and have a good diet rarely become ill, or if they do, they experience only minor symptoms and recover quickly. The elderly, malnourished, or those with compromised immunity may fare far worse to even minor infections, and sadly for those individuals common maladies may even lead to death.

Trees are no different. Robust trees that are well fed and that receive ample water are well equipped to resist even major intrusions of foreign microbes. Trees that lack nutrients, or that are heat or drought stressed are unable to mount an ample defense and are likely to succumb to the disease.

So, should we exclude Honeylocust from our quiver of tree choices? Certainly not! Given that Colorado’s harsh climate and extreme weather variables eliminate so many trees from consideration, Honeylocust are an important addition to our urban forests contributing to our biodiversity. Most trees and plants have a correlating pest or disease associated with them. Knowing this, it’s important to proactively take measures to protect and properly care for your trees.

The advice I’d offer for the care and maintenance of Honeylocust is the same I advise for every Happy tree. Water properly and fertilize regularly. Proper watering means soak the tree when you water, but give it a few days to drain and somewhat dry out between waterings. Happy Trees fertilizes every tree we plant with Green9. Green9 reads like a bottle of Centrum. It’s predominantly iron, but also provides the micro-nutrients magnesium, sodium, zink, boron, molybdenum, copper, and manganese that trees need for a healthy metabolism and immune system support. Fertilizing regularly with Green9 (March, June, and late August), fortifies trees by providing necessary nutrients.

Key to Life, the local Broomfield company that produces Green9, also offers Root Life, a concoction of live beneficial bacteria. It may sound a little gross, but we’ve learned that beneficial microbes form a symbiotic relationship with the trees and assist with water and nutrient uptake. Front Range soils consist mostly of billions of years’ dust blown off the Continental Divide, and are most often devoid of microorganisms. Inoculate the soil around your trees occasionally to enhance microbial activity in your soil, and your trees (and all your garden plants) will benefit greatly.

Visit any undeveloped open space east of the Hogback and you’ll notice that trees don’t naturally grow here. Many trees can thrive here, but only with human assistance with ample irrigation and proper fertilization. If you have crummy soil and can’t commit to caring for your trees, then Honeylocust are probably a poor choice. With a little TLC, Honeylocust trees can provide your family and community with shade, habitat, and beauty for generations to come!
 
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When you have to wash the crew truck but we’re in a drought…

Water smart, water efficiently, and plant trees!

By Chris Leinster - April 11, 2026

When you have to wash the crew truck but we’re in a drought…
When you have to wash the crew truck, but we’re in a drought? They say go to the carwash, they purify and recycle the water, and they use less water than you and your garden hose. Maybe, but the Ram 2500 turbo diesel Mega-Cab is too big for most auto-washes, and usually the bed is loaded with compost, mulch, fertilizer, tools, and other tactical tree planting accoutrements. I’m in the habit of washing the truck myself, and typically wash it in the driveway

As every skier knows, Colorado is experiencing drought conditions. Low snowpack means less water in reservoirs to supply the Front Range over the high demand summer months. These conditions are cyclical, and the State of Colorado is well prepared to provide and deliver water to every customer along the Front Range.

Still, everybody should be aware that we live in the High Chaparral, a near-desert climate with unique native plant life. Many of the trees you loved from New York, California, Washington, Oregon, and my home state of Virginia, will grow here and have been thriving for over a century. Be advised…without human assistance most of these trees would likely die.

For the most part, “water restrictions” mostly means enforcement of water conservation rules that are and have always been in effect. Check out my previous blog to learn more. Naturally, the utility company and city councils are using the current Quasi-crisis to suck up more taxpayer dollars from high water consumers.

The last thing I want to do is stir up a political debate. The blessing of the current drought is that it should make us all more conscientious of the fact that we should treat our water resources as sacred, and consume it as efficiently and as worthy as it is and ought to be.

So, I washed the truck in the yard! Goofy as it may sound, I think I did the right thing. I didn’t want to watch runoff water pour down my driveway into the gutter. So I parked my truck on the lawn and washed it in the yard! The rinse water fed the grass and trees, and the soap is actually beneficial too! Soap acts as a surfactant, and helps water slip through the soil to reach your trees! None of the water washed over the sidewalk. It was all soaked up by the earth beneath my feet.

I’ve decided to experiment this season with sacrificing my bluegrass lawn and watering only enough to keep it alive. Bluegrass is sensational as it has the ability to go dormant and die back during drought conditions and revive when conditions permit. I’m thinking just once per month, just enough to keep the crown of the plant alive.

My drip lines are different though. I intend to run them efficiently throughout the summer three times per week for fifteen minutes. Drip irrigation is efficient, delivering water only as necessary to help plants thrive. There are no current restrictions on new tree planting or drip irrigation or hand watering, nor are any under consideration. Trees offer many benefits that might help temper wild fluctuations in climate over the years. Again, my previous blog explores more…

I kinda enjoyed washing my truck in the yard. It made me cognizant of water efficiency and felt good to use the water I consumed to serve two purposes. I think this is a practice I will continue, even in water abundant years.
 
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2026 drought causes tree doubt

Plant trees to beat the heat! No restrictions!

By Chris Leinster - April 2, 2026

2026 drought causes tree doubt
Every Colorado skier knows the winter of 2025/26 was sadly one of the worst on record in terms of low snowfall amounts and warm dry conditions across the Front Range and the Continental Divide. Low snowpack means less than full reservoirs and tightening water reserves to supply communities across greater Denver metro area. Local municipalities and water managers are anticipating drought conditions, and are considering or implementing outdoor watering restrictions for the coming summer season.

Many homeowners and potential clients are under the impression that these conditions might prevent them from new tree planting and are delaying or cancelling plans to plant trees this year. The situation in reality is not so dire. The outdoor watering restrictions being considered or mandated in most communities simply follow common sense water conservation practices, and are intended to eliminate wasteful watering practices.

For the most part, the regulations simply mandate or impose watering practices that otherwise ought to be practiced, even in water abundant years. This means operating irrigation systems efficiently, directing sprinkler heads off paved surfaces, and avoiding runoff to sidewalks and streets. Homeowners are directed to water only in the early morning or evening hours when the air is cooler to eliminate evaporation in the heat of the day. This regulation is always in effect, but may be more strictly enforced during this water stressed year. Additionally, residences may be assigned specific watering days to better manage system capacity.

Bluegrass lawns can thrive under most conditions with efficient watering only three times per week. Most communities restrict watering to three days per week regardless of drought conditions. The strictest regulations under consideration that I could find are certain municipalities limiting lawn watering to only two days per week. Most jurisdictions are encouraging delaying firing up irrigation systems until May to allow reservoirs fill up to satisfy higher demand during summer months.

So, is now a good time to plant new trees, and will new tree planting even be allowed? Great news, there are no current restrictions prohibiting the planting of new trees, nor are any under consideration! As always, newly planted trees should be watered efficiently no more than three times per week. Give them a good soaking when you water, but do not water again until the soil drains and somewhat dries out.

How can you know when your tree needs water? Happy Trees installs a water gage, a simple pipe that extends to the bottom of the planting hole. Probing with a bamboo dipstick allows you to see if water is reaching the bottom of the hole, if water is sitting in the basin, or if the soil is drying out and in need of water. This Happy Trees exclusive gives you control and ensures that you provide only the water needed to help your tree thrive.

The last thing I want to do is stir up an argument over climate change, but if climate change is to blame, trees are the answer! Trees soak up the energy of the sun, converting the sun’s energy into sugars that feed the tree. They cool the ground and shade the lawn, reducing the water needed to keep the grass green. They shade paved surfaces which reflect heat back to the atmosphere. They shade houses and block sunlight from windows, reducing the energy needed to cool houses and lowering utility bills! They house and feed wildlife which may be struggling in drought-stressed seasons. Trees pump oxygen into the air to restore a balance of atmospheric gases. And they gobble up carbon, storing it in woody tissue and returning it to the soil.

If you and your family are considering planting a new tree or trees this year, there is no reason to hesitate. Every year you delay is a year’s growth lost that otherwise could be providing you shade, privacy, or just something pretty to enjoy. Planting trees this season is not only allowed, it’s the right thing to do! Call Happy Trees today and let’s beat the heat together!
 
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Much needed moisture returns!

Warming trend ahead...

By Chris Leinster - March 7, 2026

Much needed moisture returns!
The winter of 2026 will go down as one of the driest and warmest on record. Friday, March 6th, winter finally showed up. Just as the Crabapple trees and Lilac shrubs were starting to bloom, temperatures plunged and a heavy wet snow arrived! Fret not, this is excellent timing and actually beneficial for Colorado’s lawns and gardens.

While the Front Range saw temperatures dip below freezing, it didn’t get cold enough for the chill to do any harm. Most early blooming trees and shrubs, and especially flowering bulbs like Crocus and Daffodil, are well equipped to withstand minor polar plunges and will simply shake off the snow with a smile. The added moisture will surely benefit the grass and trees at the critical time of awakening from dormancy. Tree roots actually begin to stretch before you notice any top growth, which is why winter watering is so desperately important. I’ve been watering about every other week it seems like since new year’s, just to keep some moisture in the ground.

The warm temperatures allowed the Spring digging season to begin ahead of schedule, so farm dug trees are now arriving daily and we are planting! My vendors received many varieties of Maple, Oak, Linden, Honeylocust, and Elm over the past few weeks. Early flowering trees like Crabapple, Serviceberry, Pear, Canada Red Cherry, and Redbud are now on our lots. If you act quickly, we can get them planted before they blossom so you can enjoy the cacophony of flowers this year! Planting early also means the trees “wake up” from their winter slumber and begin establishing roots in your yard immediately upon installation.

Evergreen trees like Pine, Spruce, and Juniper generally arrive a bit later in the season, but I have a great selection of Pine and Spruce in 6 and 8’ sizes already. If you need Juniper or specialty evergreens like Norway Spruce, Arnold Sentinel Pine, or Bosnian Pine, let us know what you want and I’ll notify you as soon as they drop and I’ll send pictures for your approval.

Vail received a foot of fresh powder over the past week, so I’m not quite ready to hang up the skis just yet. But business comes first! If you’re thinking trees this Spring this is the moment to act, so give Happy Trees a call today!
 
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ProGreen 2026

Planting season has arrived at last!

By Chris Leinster - February 6, 2026

ProGreen 2026
The 2026 ProGreen Expo has concluded, and this means that the planting season for the new year is officially underway! ProGreen is the premier regional green industry trade show at the Colorado Convention Center. Businesses that serve all aspects of the landscape industry showcase vehicles and equipment, chemicals and fertilizers, soil and stone products, technology and business services, and of course, trees and all sorts of plant material. ProGreen offers a great way for leaders in the landscape industry to reconnect after the winter break, keep up to date with new products and best practices, and most importantly for Happy Trees, to receive updated catalogs and pricing from all our local vendors.

I am vigorously updating our tree library online and loading prices for 2026 on our website. So far, we’re seeing only modest price increases from last year. This is a welcome reprieve, as a national tree shortage and skyrocketing labor and fuel prices have led to jarring increases over the past couple of years. This is great news, and seems to be relevant across most suppliers and vendors. I am evaluating to make sure Happy Trees is offering the highest value in tree planting services at a competitive price.

The most prevalent topic on everyone’s mind is naturally the weather. It has been an extraordinarily warm and historically dry winter across the Front Range. Local growers are considering harvesting trees several weeks earlier than usual. Happy Trees may have new stock and fresh material for those wanting to get a jump on the planting season! Others prognosticate winter’s late arrival, meaning wet weather may delay spring planting once winter finally decides to show up. Happy Trees will be nimble and ready to respond to whatever the weather throws at us!

Meanwhile, homeowners should be dragging out the hoses and giving everything a good drink. Daytime temperatures are in the 60’s and will be for the next few days. Dry ground is stressful on plants, and can actually suck the water out of tree and shrub roots! Turn your hose down to a trickle and set it at the base of newly planted trees for 5-10 minutes, or use a broadcast type sprinkler like a “Frog Eye” to water a wider area for 15-30 minutes for more established trees. Your lawn could use a drink too. Although most plants are technically dormant, everything will benefit from some moisture in the soil.

Hopefully I’ll get a few more ski days in before the phones start ringing off the hook. If you’re looking to have trees installed this spring go ahead and give us a call and we’ll get you to the front of the queue.
 
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