Tag Archives: trees

tree walk.

Last Monday, my dear friend and Community Forester, Chuck Sugent, and I took a neighborhood stroll to identify trees because I find myself recommending (or “oh, that’s an oh-no-no’ tree!”) at the farmer’s market; but when it comes down to it, I can hardly identify any trees at all and rely on the Front Range Tree Recommendation List. or the Denver approved tree list. My learning style is not entirely visual but seeing and discussing something certainly increases the likelihood of future accurate recitation. After a minor location miscommunication (“Heading your way!” “Good thing you sent that. I thought I was heading your way. Oy!”), we set off through a tree-lined neighborhood between downtown and City Park.

Chuck is the kinda guy who’s gonna be the good guy: he’s got the information, and he wants to share it (perhaps with an old-timey gangster of New York wiseguy affectation). So he took no pause when I suggested the idea of a tree walk. We’ve talked about the CMG program and community forestry in terms of our own participation for community stewardship, and have oft discussed a crossover—and thus, we went! We set off to name the trees and, in addition, ended up pretend-pruning, dreaming, and trouble-shooting all the ailments. Everything I espouse, I learned from Chuck (it was a very informative afternoon). Here’s an absurdly simplistic overview of the main players:

Crabapples

Gorgeous and quite popular. Responsible for the pinkening of the city each spring. Many varieties of different sizes and fruits. Also, edible. I grew up with a crabapple tree at my grandmother’s house which was the source of many summers dares to the youngest of us to “just try it! You’ll love it!” followed by giggle fits at the sight of desperate acceptance puckering away at the tiny bite. So—raw is a no, but cooked with sugar and acid makes for delicious desserts; or my family fav: Crabapple whiskey. Fill a jar with crabapples, a cinnamon stick, ginger, cloves and top with whiskey. Tuck it away until Christmas, strain and serve.

Silver Maple

Thirsty mother lovers. They grow quickly and provide lots of shade. We have a ton of them in our metro canopy, but they are currently on a moratorium from planting in city right-of-way areas.

Honeylocust/Black Locust

Black Locust has a darker trunk than the Honeylocust. Tiny leaves, gorgeous lemon color through the fall. However, tiny leaves make a mega mess–however, however, the leaves decompose quickly and return the nutrients to the soil. Also, a popular choice in this area, and continues to be on recommended tree lists for a new planting (NOTE: many varieties are on the recommended list, but the Sunburst Honeylocust is also on the moratorium list for street planting in Denver)

Sugar Maple

Classic Canadian flag. Gorgeous flaming fall coloring. The moisture level is moderate for this group, and they do not tolerate salty soil very well but are fairly drought tolerant. 

Hackberry

This one makes Chuck’s shortlist of recommended trees for the metro area. The Hackberry has no known local pest, is native to Colorado, and drought tolerant. The Hackberry can get up to 50 feet tall, so consider this one for a street-side as a shade option. Lovely red berries darken to maroon in the Fall and provide home and a food source to the critters. Chuck calls this one a Hammer Tree; an all-around good selection.

Linden

When we happened upon our first Linden of the walk, Chuck took a step aside and said, “There are two kinds of Linden trees, and here’s how I remember them: LLL.” At this point, he raises his voice to denote the first type “LARGE LEAF LINDEN” followed by a substantially lower volume for the “littleleaf Linden.” He proceeded to crack himself up, and we carried on. There are many cultivars of Linden recommended in this area. Lindens are an attractive pyramidal shape, sensitive to salty soils, and their flowers attract bees and birds. Beware of the area you are considering, Lindens do not love high heat areas and should be planted away from any hardscaping. 

Oak

Ever sturdy and reliable. The oak leaves have a bit of a leathery texture to reduce evapotranspiration, making them more drought-tolerant, and an excellent tree choice for this area. Their leaves differ in pattern depending on the cultivar but typically have the characteristic lobes and sinuses. The Bur Oak (recommended for the Metro area), is roughly obovate with many lobes and is pale and fuzzy underneath.

Ash

If you’re reading this… need I say more? See Plum for contingency planning. We have a million (estimated 1.45 million in the Denver Metro area) Ash trees. Aside from the EAB creeping into town, the Ash tree has a tendency to appear real leggy under the canopy when not properly pruned. We saw many examples of Ash trees with a lot of deadwood inside the canopy; this can be problematic when the wind picks up. They served a great function for our canopy by growing quickly and providing robust shade; but unfortunately, we’ve got to continue considering the impending Armageddon. What build projects shall we consider for a future influx of Ashwood? Denver also has a moratorium on planting Ash trees in public right-of-ways. 

Plum

The purple leaf plum is my fan fav, and will likely be planted in my own front yard next Spring since my future self called and said: “This giant elm thing in your front yard was planted improperly, is massive, and when it goes, your front yard is gonna be U.G.L.Y.” Contingency planning in full swing. I encourage y’all to take a walkabout your own homes and chat with future self, especially regarding anything that is shade bearing. Something I picked up from my buddy whilst traipsing on the tree walk: purple leaf plums require regular pruning for flowering (Is anyone else as smitten by the plurality of prunes in this context?)  Remove the deadwood and prune 1/3 the length of new growth. We found a perfect example and made pernicious prunes with finger scissors.

Colorado Blue Spruce

Beautiful. Also better at a higher elevation. We did see a few stunners, though, and learned a neat trick for tree ID: the leaf of a fir tree will be flat and flexible. Spruce, on the other hand, will be square and sharp (see what he did there?). Grab a leaf, roll it between your fingers, and name it quickly with this handy guide.

Photo by Dids from Pexels

Aspen

May make it to a mature size but inevitably will crash and burn. I’ve been touting this gospel for a while now, and take every opportunity to point out a struggler to my wife. which has become problematic, because now she counters by showing me all the healthy Aspen in the Metro area. The truth of the matter is an aspen tree (or maybe even a small clump of them) has the ability to thrive with the proper tender loving care… for a while. Above and beyond the statistically insignificant number of Aspen in the front range who appear to be doing well, they aren’t built for this elevation, and forcing them to do so causes undue stress, and makes them more vulnerable, hastening their predisposition to die anyway. Don’t do it. Go to the mountains more often and enjoy them in their own territory.


Beyond my self-imposed (and singularly played) trivia that entailed me interrupting, pointing, and shouting guesses; we also discussed the conversational piece of tree maintenance. Chuck indicated he has many chats with his neighbors about their trees and takes these moments to build his community and integrate his passion with friendly educational moments. We discussed the evidentiary tribulations of a tree in demise, that twists it’s trunk and bears the stripes of turmoil. We debated the suckers: their yappy attempts to address internal stress, and what to do with them (should we leave them and let it try to capture the energy it is craving? OR whack them back always? And when?) We talked about injury to a tree, and how the tree may cover and scab the wound, but the wound remains and the tree is still vulnerable. Chuck showed me a hackberry tree covered in galls. We both got lost in our attempts to recall the origins but settled on something about defense mechanisms and how they rarely hurt the tree.

As we were nearing our last corner on the way home, Chuck remembered a tree we hadn’t encountered that he loves. I’ve developed a habit this summer that whenever I see this tree, I shout it’s name, probably because it’s so fun to say, but shouting also seems appropriate just to communicate the whimsy of the CATALPA! Just try and say it without a bit of a shout. The Catalpa is also a recommended and robust tree for our area. It’s got those built-in wands and/or swords for play, and bright green wide leaves provide a huge amount of shade. . They are another tough tree, worthy of your scape.

Other items on Chuck’s “Oh no-no” list? Planting a tree too deep? Oh, no-no. Scoffing at the bare root and opting for a burlapped and caged tree? Oh, no-no. Planting anything from the Birch fam in Denver? Oh no-no.  Hiring an arborist annually to tame your trees? Oh, no-no. With a little reading, Youtube-ing, or friendly forester finding, folks can save bunches of bucks by learning how to make the minor pruning adjustments to your tree every year to avoid the future big bills from an arborist. Trees can easily be grown and cared for by their owners working from reliable and factual info. Of course, always consult a pro when your tree questions start toeing the line safe vs. unsafe. 

https://extension.colostate.edu/topic-areas/yard-garden/#trees

As DMG’s we get loads of questions about trees at the farmer’s markets. We try our best to offer small sagelings of fact-checked info, but what I’ve found to be more helpful is keeping the company of a forester. Trees are just as essential to the garden crew as our lawns, beds, and weeds. I encourage everyone to branch out (a thousand apologies for that one) and get connected–or get involved and become a Community Forester, yourself!


PS. Did you know if you live in Denver you can get nearly *free* trees?

By McKenna Hynes

Apprentice Colorado Master Gardener since January 2019

Is a new tree on your wish list?

Not all gardeners enjoy reading seed catalogs.  If you are more interested in planning for a new tree then here are a few resources to get you started.

Aspen Suckers – Persistence Pays!

For many years, my property line was bordered by a small patch of aspen trees planted by a well-meaning neighbor. They were lovely for a few years but despite good care, things began to change – fungal diseases, insects and visible cankers, anemic fall color, as well as “gifts” in the form of aspen suckers peppered both lawns. While I’m not a lawn zealot, these suckers can rather quickly turn into a mini grove of trees as aspens reproduce by sending up shoots from the root of the mother tree. Suckering sometimes indicate that mom is on the decline, which in this case was true.

In early spring 2014, the owners decided the aspens were beyond saving and they removed the ten year old trees. With the trees gone, the  suckers continued to sprout with a vengeance, as the remaining underground root stock tried to offer us replacement aspens.

To win this battle, before every mowing (and sometimes more often) we diligently removed the tender new shoots and their roots by hand and dabbed freshly cut larger suckers with a product recommended by our local garden center (look for active ingredient Ethyl 1 Napthaleneacetate). Ideally, we would have tackled this without chemicals, but in this case, we were advised to go this route. Additionally, we aerated the lawn and over-seeded the grass to make it healthier and thicker, hence more difficult for suckers to emerge. To discourage sucker production, we were vigilant about not over watering.

I am proud to say that this year our persistence has paid off. We’ve not had a single sneaky shoot in the lawn or adjacent garden bed, even with this year’s abundant moisture. The remaining root stock appears to have died out, so (fingers crossed) the suckers are gone for good. For more info on reducing tree  suckers and seedlings: http://www.ext.colostate.edu/ptlk/1538.html

Our experience is very common. Aspens are beautiful in the mountains, but ill-suited for the urban landscape. At lower elevations they are frequently disease prone, insect plagued and short lived. Since they thrive in moist, well-drained and slightly acidic soil and at higher altitudes, the Front Range soil, which is predominately compacted, alkaline and clay, is just not ideal.  If you already have aspens on your property, here is information which may help you keep them at their best: http://www.ext.colostate.edu/ptlk/1701.html

If you are thinking of adding trees to your front range landscape, check out this list of tree recommendations from Colorado State University http://www.ext.colostate.edu/pubs/garden/07418.html

Written by Linda McDonnell, a Denver County Master Gardener since 2013

One Less Ash Tree for Emerald Ash Borers

yellow tree leaves
When I planted a white ash tree about 10 years ago, I never dreamed I’d be chopping it down while it was still healthy. But I did just that earlier this season and took the loppers to the tree while it was sending out new leaves.

I decided to take action now instead of waiting for the Emerald Ash Borer (EAB) to take it out one day in the future.

It wasn’t an easy decision. I liked this tree a lot, especially in the fall when the leaves turned a brilliant yellow. But it’s only a matter of time before the dreaded EAB makes its way into my landscape and forces my hand.

The tiny Emerald Ash Borer has already caused the death or decline of tens of millions of ash trees in at least 20 states and now it’s in Colorado.

I chose to remove the tree this season to avoid my limited options in the future. Like other ash-tree owners, I’d have to decide whether to budget for the expense of treating a taller tree with insecticides every one or two years to prevent EAB damage or wait for the borers to kill the tree slowly and then hire someone to remove it for me.

Now that this ash tree is gone, I can take my time and find another kind of tree to replace it.

Then I’ll be able to focus my preventive efforts on the much larger ash that shades most of the front yard. That tree is more valuable and will be worth the cost of treating it, once the time comes.

Right now, home owners and urban foresters in and around Boulder are trying to make the same kinds of decisions. They’re deciding whether to treat their trees with insecticides — while weighing the costs with the environmental hazards; measuring the effectiveness with ease of application.

If you have ash trees on your property, you’ll have to make similar decisions in the future, too. Now’s a good time to start thinking of what you’ll do once the EAB invades your landscape. Would you remove a healthy ash tree as a drastic measure to prevent EAB in the future?

There are some good resources to help you decide, including CSU’s Department of Bioagricultural Sciences and Pest Management website and the Colorado Department of Agriculture EAB website that includes an Ash Tree Zone interactive map and a way to sign up for the EAB newsletter to stay informed.

By Jodi Torpey
A Denver master gardener