Category Archives: Uncategorized

Indoor Plants & Clean Air


Over thirty years ago, NASA began researching methods of air purification in space crafts to pave the way for long-term human space flight. The study, found here, concluded that many common houseplants are highly effective at removing toxins such as benzene, formaldehyde, ammonia, xylene and trichloroethylene. The findings have been replicated many times over. Their relevance today is unmistakable, especially given the number of man-made products which off-gas chemicals in our homes and workplaces, current energy-efficient construction practices, our focus on healthy living and concern for the environment.

The following are answers to commonly asked questions about the relationship between clean air and indoor plants.

How exactly do plants clean the air?

Plants are effective at absorbing gases through pores on the surface of their leaves. It’s this skill that facilitates photosynthesis, the process by which plants take in carbon dioxide and release oxygen. In effect, all plants can purify the air to some extent, but some do a better job than others.

Studies show that plants can absorb many gases, including a long list of volatile organic compounds (VOCs). Benzene (found in some plastics, cloth and pesticides) and formaldehyde (found in some cosmetics, dish detergent, fabric softener and carpet cleaner) are common indoor VOCs that plants help eliminate.

Plant roots and the microorganisms that live in healthy soil also absorb VOCs and other pollutants.

Which plants were used in the NASA study?

Most were common, easy to care for plants which you may have in your home or office right now. Top “air filters” included: Peace lily (Spathiphyllum wallisii), golden pothos (Scindapsus aures), mother in law’s tongue (Sansevieria trifasciata ‘Laurentii’), bamboo palm (Chamaedorea sefritzii), dracaena (Dracaena marginata), spider plant (Chlorophytum comosum), English ivy (Hedera helix), Chinese evergreen (Aglaonema commutatum). Gerbera daisies (Gerbera jamesonii) and potted mums (Chrysantheium morifolium) are also effective air purifiers, but tend to be short-lived flowering houseplants.

Can plants reduce the harmful effects of cigarette smoke in the air?

Cigarettes contain formaldehyde, one of the toxins that plants can remove from the air. However, the plant/cigarette smoke connection was not the focus of the NASA study. A 2010 study by the American Society of Horticulture Science found that ferns were among the most effective plants in formaldehyde removal.  Check out the study for specifics on which ferns offer the best results.

Do I need to live in an indoor jungle to reap benefits?

Hardly! Studies found that approximately one 6″ to 8″ pot per 100 square feet, or 15-18 plants per 1800 square foot house makes a measurable difference.  The more vigorous the plant, the more pollutants it will draw from the air.


Photo credits: Bing free images

Written by: Linda McDonnell, a Denver County Master Gardener







How to Read a Seed Packet

seed packetsIf you can read and follow instructions, you can grow a garden.

Most seed packets have all the information a gardener needs to plant and grow whatever seeds are hidden inside. Whether you want to plant flowers, herbs, fruits or vegetables, let the seed packet be your guide.

Instead of falling for the picture on the front of each packet, study the back, especially the number of days to harvest for fruits and vegetables. Our area has a limited number of days for growing each season, and the fewer the days to harvest (especially for tomatoes), the more success you’ll have.

Here’s the most important information seed companies want you to have — and to use:

Plant name–Both the common name, like Bloomsdale Longstanding spinach, and the scientific name, Spinacia oleracea.

Type of plant—Types can include heirloom, hybrid, organic and other identifiers.

Plant description—The description includes basic information on whether the plant is an annual, biennial or perennial and some of its key features. The plant’s history, height and width may also be included.

Packed for date—Seeds are packed for and sold by the current year; however, seeds packed for previous years are usually good to plant for several years.

Planting time—Planting time depends on weather conditions for a specific area. Some packets include hardiness zone maps with a month or a range of months for planting.

Seed packets will also give information on whether to start seeds indoors or to plant seeds outside.

  • Start seeds inside according to the packet’s recommendation, usually 6-8 weeks before the average last frost date.  CSU Extension offers a guide to frost dates to help with garden planning. Avoid planting seeds too early.
  • Plant seeds outdoors after the soil has dried and warmed to the optimum soil temperature. A CSU Extension handout and a kitchen or digital thermometer will help determine when to plant specific vegetables. Planting too soon or too late could be a reason some seeds fail to sprout.

Light needs—The amount of sunlight plants need from full sun to partial shade. Most fruits and vegetables need at least 6 hours of sun every day.

Row spacing—The amount of space between rows allows enough space for plants to grow without being crowded.

Planting space—Spacing is also critical between individual plants. Spacing may include how closely to plant seeds and how to thin the plants once they start growing.

Seed depth—Use a ruler or other guide and follow seed depth recommendations. If seeds are planted too deep, they may have a hard time reaching the top of the soil.

Days to sprout or germinate—Keep track of germination dates so you’ll know the timing of when plants start to grow. If seeds fail to sprout, replant seeds and they should catch up quickly.

Days to harvest (or mature)—For vegetables, the harvest dates will vary depending on the variety or cultivar. Harvest fruits and vegetables when they’re at their peak and avoid leaving vegetables on plants too long.

Special information—Depending on the seeds and seed company, there may be growing notes, staking information, fertilizer recommendations, suggestions for cutting or harvesting, recipes and other tips for success.

By following the seed packet instructions, gardeners can guess less and get more enjoyment from their gardening experience.

By Jodi Torpey
A Denver Master Gardener

Save the Date! 13th Annual Denver Master Gardener Plant Sale May 19-20th

8th Annual CMG Plant Sale, Harvard Gulch Park, Denver CO 5-18-13 (6)Saturday May 19th 8am – 3pm & Sunday May 20, 2018 10am – 3pm

CSU Denver Extension, 888 E Iliff Ave, Denver CO 80210

Rain or shine. Now accepting credit cards!

For more information: (720) 913-5270 or 

Heirloom and modern hybrids
Annual and perennial flowers
Sweet and hot (New Mexico) chiles
Gardening questions answered

Five Nature Activities to Do With Children in Winter

Want to share your love for nature and plants with children this winter? Here are five activities to spark curiosity, teach and amuse.


Adopt an insect-eating plant. The Venus Flytrap (Dionaea muscipula) is fascinating to watch as it traps spiders and insects for its meals. This animation explains the process.


Start a worm farm. It’s a fun way to learn about the composting process and add to the garden later in the year. All that’s needed is a plastic lined or wood box with a lid, vegetable scraps, shredded newspaper and a few red wriggler worms. Kept moist and cool, the worms will get to work making valuable compost.  Find full instructions here.

FairyGardenPeekInside-e1403316493327-2Plant a terrarium or fairy garden. Assemble a collection of small plants in an open-topped container or create an imaginative, kid-friendly scene with structures and characters – perhaps a park for superheroes or dinosaurs! Children love to play in the dirt, so this makes for great hands-on learning of planting basics. Stick to easy to grow, petite plants and add a bottom layer of pebbles if using containers without drainage holes. pineconebirdfeeder-1

Feed the birds. Gather some pine cones and tie a string to the top of each, slather with peanut butter, then roll in bird seed. Hang in a nearby tree and watch the feast begin.


Sprout an avocado pit. Stick the perimeter of an avocado seed with toothpicks and suspend it, rounded side down in a glass of water. Watch for roots followed by a green shoot. Avocado is a fast growing plant and will soon need to be transplanted into soil.

What nature activities do you do with children?

Images:  Bing Images (Royalty Free)

Written by: Linda McDonnell, a Denver County Master Gardener



Shedding Light on Houseplants


Daylight saving time is on hiatus, the gardening season has drawn to a close and  the long shadows of winter will soon be here.  It seems like a good time to turn our attention to the light needs of indoor plants.

Most indoor plants hail from the tropics, making their ideal growing conditions far different from what we offer in our typical homes. Thin new leaves, loss of lots of older foliage and limbs stretching towards a window can all be signs that your plant is craving more light. Without adequate light plants are unable to store energy for growth.

Indoor light is more subtle than the light in our gardens, which can make it trickier to assess. For more precision, a photographer’s light meter or a simple light meter app on your phone will measure the light in foot-candles or LUX units. Horticulturists use foot-candles, so if you have a device which gives a LUX reading, search the web for an easy LUX to foot-candle calculator.

In general, growers characterize plants as needing high, medium or low light.  Here are some guidelines to help assess the type of light in your environment with greater accuracy.

High Intensity Light

  • 1,000+ foot-candles
  • 4-6 hours of sun per day
  • Crisp shadows and dark contrast at the brightest time of day
  • Within 2’ of east facing windows
  • Within 2’ of south-facing windows (October-March)

Medium Intensity Light

  • 500+-1,000 foot-candles
  • Within 2’ of north facing windows (April-September)
  • 2-6’ from an east or west-facing window
  • 1’ to the side of an east or west-facing window
  • Approximately 10-14 hours per day of fluorescent office light

Low Intensity Light

  • 50-500 foot-candles
  • Faint shadows at the brightest time of day
  • Within 2’ of north facing windows (October-March)
  • 6-10’ from south-facing windows (April – September)
  • Few plants survive in fewer than 50 candles

Knowing the light intensity will help determine the best placement of  plants and select  plants which will thrive. Variables such as humidity, drafts and temperature also factor into a plant’s health, so be sure to take this into consideration, too.  As always, knowledge and keen observation skills are key to successful plant care.

Additional information on plants and light:

Plantalk 1352: Interior Plants and Light

Plantalk 1314: Houseplants: Artificial Light

Starting Seeds Indoors

Christmas Cactus Care (effects of light on bloom)


Written by Linda McDonnell, a Denver County Master Gardener





What’s In The Cauldron? The Meanings Of Plant Names


“Fillet of a fenny snake,
In the cauldron boil and bake;
Eye of newt and toe of frog,
Wool of bat and tongue of dog,
Adder’s fork and blind-worm’s sting,
Lizard’s leg and howlet’s wing,
For a charm of powerful trouble,
Like a hell-broth boil and bubble.”

Doesn’t that just send a shiver down your spine? The immortal words of Macbeth’s witches tend to hang in the air, and you can almost hear the cauldron bubbling.
But what is that stuff in the cauldron?

Guess what? Most of it is plants!

Anyone who has worked in the garden has noticed that many plant names have odd, fanciful or gruesome names. If you really consider them, names like ‘dandelion’, ‘foxglove’ and ‘mistletoe’ are pretty odd, aren’t they?
The reason is multi-faceted. A large contributing factor is a socio-historical phenomenon known as ‘linguistic drift’, which is the term for the fact that words are changed over time. Originally, according to Oswald Cockayne’s ‘Leechdoms, Wortcunning, and Starcraft of Early England: The History of Science Before the Norman Conquest’, Dandelion was originally ‘Dent De Leon’, or ‘Lion’s Teeth’, referring to the dentition of the leaves.  Andrew Yang notes another good example in his work ‘Plant Names in Old and Middle English: Problems and Trends in Taxonomy’ : “The tan of mistletan, notes Sauer, “originally meant ‘twig,’ but it was later associated with tan [as OE] toe,” to form mistletoe.”

Another main contributing reason is pragmatic: it’s hard to forget a plant called ‘dead man’s fingers’ or ‘bear’s breeches’ as a rule, which made remembering and passing on plant knowledge much easier.

The Tryskelion Press gives us a short guide to the 16th century English plant name meanings in their August 2015 issue.

Old Name for Part Actual Part of the Herb Used
Eye Inner part of a blossom
Paw, Foot, Leg, Wing, or Toe Leaf
Guts Roots and stalk
Privates Seed
Hair Dried, stringy herbs
Tail Stem
Head Flower
Tongue Petal
Heart A bud or seed

Here’s a few examples of the common names in the 16th century and the same plants today.

Old Herbal Name Herb/Plant Name
Adder’s Fork Adder’s tongue
Adders Tongue Dogstooth Violet
Ass’s Foot or Bull’s Foot Coltsfoot
Bat Flower Tacca
Bat’s Wings Holly
Bat’s Wool Moss
Bear’s Foot Lady’s Mantle
Beggar’s Buttons Burdock
Beggar’s Tick Dianthus
Bird’s Eye Germander Speedwell
Bird’s Foot Fenugreek
Black Maidenhair Black Spleenwort
Black Sampson Echinacea
Black Snake Root Black Cohosh
Blind Eyes Poppy
Click Goosegrass
Clot Great Mullein
Corpse Candles Mullein
Corpse Plant Indian Pipe
Courtesy Summer Wind
Crocodile Dung Black Earth
Crow Corn Ague Root
Crow Foot Wild Geranium
Crowdy Kit Figwort
Crown for a King Wormwood
Cuckoo’s Bread Common Plantain
Dead Man’s Ashes Mandrake root
Death Angel Agaric
Death Flower Yarrow
Devil’s Apple Datura
Devils Dung Asafoetida
Devil’s Eye Henbane, Periwinkle
Devil’s Flower Bachelor’s Buttons
Devil’s Guts Dodder
Devil’s Milk Celandine
Devil’s Nettle Yarrow
Devil’s Oatmeal Parsley

So what was in that cauldron? Black mustard, Crowfoot, Holly, Horehound, Wormwood, and a lot of other rather powerful plants. I wouldn’t drink a cupful myself, but if you want to see visions and fly this brew would definitely do it.
Happy Halloween!


The Shakespere Standard,

Cockayne, Oswald.  Leechdoms, Wortcunning, and Starcraft of Early England: The History of Science Before the Norman Conquest, vols. 1-3.  Bristol, England: Thoemmes Press.  1864-66.

Gledhill, D.  The Names of Plants, 2nd ed.  Cambridge: 1989.

Andrew K. Yang, Plant Names in Old and Middle English: Problems and Trends in Taxonomy 

The Old English Herbarium (OEH) and Medicina de Quadrupedibus.  Hubert Jan de Vriend, ed.  Toronto: Oxford.  1984.

Tryskelion Press, Old World Names For Herbs And Plants,


2018 Colorado Master Gardener/Colorado Gardener Applications Now Being Accepted

2016 gardenline 9

We are now taking applications for the 2018 Colorado Master Gardener volunteer class. We are also recruiting Colorado Gardener Certificate students who take the classes without volunteering. The application deadline is October 18th, 2017 and weekly Wednesday classes run from January 24 through April 10, 2018 from 9:00am-4:00pm. Classes will be held at Denver Botanic Gardens and Jefferson County Fairgrounds. For more information about the program, please visit our website:

If you are interested, please call 720-913-5272 or email for an application.

If you live outside of Denver, please see this link for the CO Master Gardener Program in your county:

Gardens in the Sky


Denver Private Residence. Courtesy of Denver Green Roof Initiative

Green roofs or living roofs have been around for thousands of years. The Hanging Gardens of Babylon were constructed around 500 B.C. using tar and layers of reeds to waterproof structures, upon which lush plants thrived. Europeans have long embraced green roof design and today, about 10% of homes in Germany have living roofs. North America has been slower to adopt green roof design, but the practice is gaining momentum, particularly in urban areas including Chicago, New York, Portland and Washington DC. This November, Denver residents will vote on The Denver Green Roof Initiative, modeled after legislation in Vancouver, which requires commercial buildings in excess of 25,000 square feet to dedicate a portion of roof space to vegetation or solar panels.

Image courtesy of

What are green roofs and why are they valuable? A green or living roof is one that is either partially or completely covered in vegetation on top of the human-made roofing structure.  There are two major types of designs – extensive and intensive. Extensive green roof systems include a thin waterproof membrane covered in a lightweight, shallow planting medium and low maintenance plants, often using a system of trays  Intensive green roofs involve a more complex system of layers, are more expensive, require greater structural support and allow for a wider range of vegetation, such as trees and shrubs (see diagram). Intensive green roofs can serve as parks or public spaces, such as the Mordecai Children’s Garden at the Denver Botanic Gardens or Highline Park, built upon an elevated historic freight line in New York City.

Anschutz Wellness Center -University of Colorado, Aurora. Courtesy of Denver Green Roof Initiative

Denver has the third highest heat island effect (the average daily urban-rural summer temperature difference over the past 10 years) in the country.  Green roofs moderate the HIE by cooling ambient air through evapotranspiration. They also provide summer and winter insulation to buildings thereby reducing the carbon footprint. Other benefits include decrease in stormwater contamination, reduction of pollution by filtering the air as it moves across the roof, additional wildlife habitat for birds, insects, spiders and other animals and absorption of noise. While green roofs, especially extensive designs, are expensive, they have been shown to last longer than traditional roofing resulting in long-term cost benefit.



Denver EPA Headquarters Courtesy of Denver Green Roof Initiative

The 20,000 square foot green roof at Denver’s Environmental Protection Agency Region 8 Headquarters  was installed in 2008 in partnership with Colorado State University and other organizations. Using a system of 2′ by 4′ plastic trays, plants were studied for exposure to winter and summer extremes, wind exposure and soil conditions, among other factors. The roof contained four species of Sedums, including Sedum album (white stonecrop), Sedum kamtschaticum (Russian stonecrop), Sedum acre (goldmoss stonecrop) and Sedum spurium (two row stonecrop) and three varieties of Sedum spurium: ‘Dragon’s Blood’, ‘John Creech’ and  ‘Red Carpet”.  According to the researchers, “These plants were selected for visual appeal as well as survivability in harsh environments with temperature extremes, and for their capacity to withstand drought conditions better than most plants.” Another outstanding performer was the brittle prickly pear, Opuntia fragilis. According to Dr. Jennfer Bousselot, “It’s spectacular especially since it has been virtually untouched since the formal study ended in 2010. It has thrived on only light irrigation during the growing season.” Find extensive documentation of the project here.


Green roof design addresses many environmental concerns. Will it “take root” in Colorado?  To learn more about green roof design and Denver’s upcoming ballot initiative, here are some additional resources:

National Public Radio: Do Cities Need More Green Roofs?

The Denver Green Roof Initiative (includes ballot initiative)

The Denver Post, March 14, 2017. “Green roofs will benefit Denver but they shouldn’t be mandated”


Written by Linda McDonnell, a Denver Master Gardener























Do Japanese Beetles Prefer Some Roses More than Others?

Colorado roses have been attacked by Japanese beetles for several years, leaving behind ravaged foliage and deformed flowers. Curiously though, some gardeners report that their roses suffer little to no damage from the insect. Are some rose cultivars less enticing to the Japanese beetle than others? This was the focus of Colorado State University’s 2016 observational study conducted at Littleton’s War Memorial Rose Garden. In the first year of this multi-year study, the following rose cultivars were not found to be damaged by Japanese Beetles: Angel Face, Debut, Hondo, Joseph’s Coat, Mardi Gras, Picotee, Popcorn, Prima Donna, Ralph Moore, Singin’ in the Rain and White Lightnin’.

Conversely, the following cultivars were observed to have the highest levels of Japanese beetle destruction: Pink Promise, Honey Perfume Whisper, Love and Peace, Day Breaker, Strike it Rich, Cherry Parfait, Eureka, Starry Night, Rainbow Knock Out, Lady Elsie May, Carefree Delight and June Lover.

Adult Japanese beetles destroy flowers at the same time bees are gathering pollen, making their impact even more significant. For this reason, CSU’s study identified roses with high Japanese beetle susceptibility and high visitation by bees. Topping this list were Rainbow Knock Out, Lady Elsie May and Strike it Rich. Also in this group were Prominent, Home Run, Easy Does It, Apricot Nectar, Gemini, Starry Night, Baby Boomer, Sweet Diana, Julia Child, Cathedral, Betty Boop, Mon Cherie and Cloud Dancer.

Early findings suggest that gardeners may be able to lessen damage to roses by planting cultivars that are less attractive to Japanese beetles. It also underscores the importance of close monitoring and care of plants to reduce the effects on pollination. In the future, additional information on why some cultivars are preferred over others is likely to emerge.

This CSU publication provides comprehensive information on caring for plants infested with Japanese beetles, the larvae stage effecting turf and more. An additional bit of advice – it has recently been found that crushing the Japanese beetle does not attract more beetles. So, while we’ve previously been advised to handpick and drown the insect in soapy water, feel free to stomp on them too. Since they are night feeders, they are easiest to find around dusk, when they are about to feast on your plants.

Written by Linda McDonnell, a Denver County Master Gardener

Note: The study cited in this post was presented to the Denver County Master Gardener Association by Dr. Whitney Cranshaw of Colorado State University in May 2017.

Photos courtesy of















TREES, glorious trees

Trees. They are all around us.  In our gardens.  In our parks.  On the street.  Yet we barely notice them most of the time.  Gardeners tend to forget that they are plants like any other.  Non-gardeners tend to regard them as more or less permanent objects in the landscape.

I’ve recently been helping with the Al Rollinger Tree Survey being done by Denver Botanic Gardens and The Denver City Forester’s Department.  (For more information on this, see  This has taken me to different parts of the city, looking at trees in yards and on the street.  For each tree in the project we identify the tree, measure its diameter and height, assess condition, take a photo and get the GPS location. This close examination has given me a new appreciation of these giants of the plant world.

Denver is at the western edge of what was once short grass prairie all the way to Kansas City.  Trees are not native to this landscape apart from the odd plains cottonwood near water.  All the trees planted and growing in our city are imported here, whether from the higher ranges in the mountains (pine, spruce, aspen) or from the north and east (maples, oaks).

Why plant and grow trees?

Yes, it can be difficult to grow healthy, long-lived trees here.  Too little water, alkaline soil, heavy clay, too hot in summer, too cold in winter, traffic pollution, concrete and blacktop suffocating roots.  These are the same problems that challenge us in our back yards as we try to get our shrubs and flowering plants to perform for us. But with a little care and attention, we can grow healthy trees. Just look at the many benefits trees bring:


  • Provide oxygen
  • Reduce carbon dioxide levels
  • Improve air quality through absorption of pollutants
  • Absorb and retain water to reduce run-off and delay onset of peak flow (flooding)
  • Reduce soil erosion
  • Improve capacity of soil to absorb water
  • Provide animal, bird and insect habitat
  • Reduce noise levels
  • Reduce stress
  • Reduce UV exposure


  • Shade and cool our homes and streets
  • Save energy (natural cooling through shade v. AC)
  • Provide wind breaks


  • Increase property values and reduce crime
  • Improve walkability of neighborhoods
  • Provide beauty

Get to know our trees

You can find out about every single tree growing in the street and public rights of way in Denver by typing in an address in the city’s “Treekeeper” program at  When I walk the dog around the neighbourhood, I look up now and try to identify the trees I walk by (or underneath).  If I don’t know one, I take a note of the address and check on the Treekeeper when I get home. (Because of the vast amount of data involved, the program doesn’t work well on a mobile device.)

Some trees are “champions”. These are trees that have attained a large size (based on species) through girth, height and crown size.  You can find out about Colorado State Champions here and National Champions here 

Choosing and buying a tree

A tree can be a big financial investment and selecting the appropriate tree is very important if you want it to not just survive but to thrive for many years.  The CSU Extension Service publishes a very helpful list of trees recommended for the front range. You can find it here:

The non-profit organisation, The Park People, has a scheme called Denver Digs Trees for selling street and yard trees at subsidised prices (or even for free in some locations) every year.  The trees they sell are all considered suitable for Denver. You complete an application form in January or February and the trees are distributed in mid-April.  They will even come and plant your tree for you if you need help. You can find them here:

Look for trees in Colorado nurseries and garden centers which grow their own trees.  A tree which started life here is likely to be better adapted to Colorado growing conditions than one imported from another state.

Before you plant

When planting a tree whether in your yard or the street, you need to get the position of all utility lines checked before digging . You can get the utility lines checked for free by calling 811.  You also need a permit from the City Forester before you plant a tree in the street i.e. the public right of way.  The permit is free and can be obtained by email. See here for details:

Tree problems

Like all plants, trees can have problems.  Pests and diseases or hazards caused by natural events, like storm damage.  Often problems stem from human actions.  Improper planting, insufficient or too much irrigation, damage from garden tools like mowers and weed-whackers, root damage from nearby construction, damage from staking and guy wires, pet damage, root damage from landscape fabric or inappropriate mulching e.g. river rock.

Emerald Ash Borer

The biggest problem facing trees in Denver right now is the threat of the Emerald Ash Borer (EAB). This pest came from Asia where their ash trees are immune to it.  Unfortunately, American ash trees are not.  Its presence has been confirmed in Boulder since 2013 and in Longmont since 2016.  It threatens to wipe out all the ash trees in Denver if (when?) it gets established here.  That’s 1 in every 6 trees in Denver or 1.45 million trees.  For information and advice about EAB go to

To try and mitigate the effect that EAB will have on our city trees, the City Forester’s Dept, in association with The Park People’s Denver Digs Trees program, is offering new street trees now for FREE.  By planting in advance of the arrival of EAB, the aim is to mitigate the effect of the EAB and increase diversity in the city’s tree population. You don’t need to have an ash tree already or any kind of street tree, just room to plant a new one.  To apply for a new street tree, go to  They will even plant it for you!

Learn more about trees and get involved

The Park People run a program with Denver’s City Forester’s Dept which trains volunteers to become Community Foresters.  Volunteers assist the City Forester’s Dept by becoming qualified to lead and participate in tree planting and tree care projects in their neighborhoods.  Courses are run every year.  More information can be found at

Get more information about trees

You can find useful information and get advice on all aspects of trees from the following:

Your local City Forester (arboreal inspector) – find him/her at

CSU Extension Service ‘Ask an Expert’ –

Ask a Master Gardener –

The Park People –

The Colorado Tree Coalititon –

A professional arborist – see the list of arborists licensed to operate in Denver at

Look up, learn more and enjoy our trees!


Anne Hughes/A Denver County Master Gardener

Photo by Anne Hughes