by Marilyn Loser

Vince Urbina, Colorado Community Forrester, recently gave a presentation on tree care during drought. “Drought is a deficiency of rainfall over a period of time resulting in a water shortage for some activity, group, or environmental sector,” stated Urbina.

Tuesday’s storm dumped .64 inches of precipitation according to the Wunderground website, the highest daily amount in the past year.  In fact, we’ve only had 5.16 inches of precipitation in the last year and 12% of that came Tuesday. Sounds like drought to me.  Most trees in Alamosa need supplemental water to keep them healthy.

Urbina asked the audience how much water a tree needs:  2 gallons? 10 gallons? 20 gallons? He then explained it was a trick question. Each tree’s situation is different. “Water it until it’s happy!” Urbina exclaimed.

How do you do that? Before answering that question it’s important to understand the anatomy of a tree. Most tree roots are in the top 2 feet of soil and, in a nature situation, extend well beyond the leaf canopy. The roots need water and air. He shoots for 6” of new growth each year.

Urbina suggests watering deeply (14” – 24” down) and infrequently. Water around the entire drip line (the line under the outer edge of a tree’s branches where water would drip to the ground in a rainstorm).

He outlined 3 watering methods. Drip irrigation and micro sprinklers both conserve water by putting it only where it is needed.  Typically fertilizer can be applied through either of these methods.  Drawbacks include the need to filter ditch water (chunks can clog tubing) and control weeds.

Using a Ross root feeder is Urbina’s preferred method. The root feeder is a T-shaped metal device about 2 feet long. You hook up the hose to one end of the T top and water comes out the bottom.  You plunge the device into the soil at the drip line.  If the soil is dry and/or compacted, it might not go in very far at first.

I’m now the proud owner of a root feeder and found after a couple of minutes I could push the root feeder in 16” or so. For my smaller trees, I watered at 4-6 places along the drip line for about 5 minutes each trying to soak the top 16” – 20”.  For larger trees I watered at 8 places for about 10 minutes each.  Was this enough?  I’m not sure. I’ll check the soil moisture in a couple of weeks.

This works for established trees.  But, what if you’re designing your yard landscape? Urbina strongly suggests planting trees with trees and turf with turf rather than planting trees and turf together.  People often water their grass 3 times per week for about 20 minutes.  This is NOT good for trees.  The grass, with its shallow roots, absorbs the water and very little percolates down to the tree roots.

Most people buy container trees.  Urbina likes #15 size containers that typically hold 1 ½” to 1 ¼” diameter trees (measured 6” from the ground).  It’s easy for 2 people to handle a tree of this size.  These smaller trees are less expensive than larger caliper trees and recover faster.

Balled and burlapped trees are another popular choice. Urbina notes, “For every inch of caliper at 6” above the soil, it takes that many years for the tree to reclaim roots lost [in the ball/burlap process].  A 2” diameter tree takes 2 years to recover.”

Plant the top of the root ball 1” – 2” above the surrounding soil, especially in clay.  It’s a good idea to create water basins around the trees for the first year. About 75% of trees and shrubs sold are in containers and given daily water at the nursery.

Once you’ve planted a container tree, water it at least weekly until it is established.  Then back off on the frequency – it takes some time for the tree to adjust to a new watering regime. Mulching under the tree canopy conserves water by reducing evaporation.

A future article will discuss the trees Urbina suggests for Alamosa.  Meanwhile, visit AlamosaTrees.net for ideas.

6^th Street tree planting – Saturday, May 12, 10 am: Join the Alamosa Tree Board and Department of Parks and Recreation to plant trees on the south side of 6^th Street between San Juan and Ross. We were unable to plant trees along 6th Street during Alamosa Arbor Week due to utility line conflicts. The utility lines have been marked and planting locations worked out.

“We may not be able to clean up our cities overnight, be we can start to make a difference by making them greener places.  Planting a tree may be the simplest, most immediate, and most effective way to make a personal commitment to the environment.” Graham Nash

by Marilyn Loser

Alamosa will celebrate Arbor Week 2012 from Saturday, April 28, through Friday, May 4. Please come help us plant trees along Sixth Street and in the Alamosa Cemetery. And help us celebrate being a Tree City USA for the 22nd year and for receiving their Growth Award for the 11th time.
Did you know Alamosa is one of only 8 Colorado communities to receive the Sterling Tree City Growth award? The Sterling Award, a part of Tree City USA, is presented to communities that have received the Growth Award for 10 years. According to the Arbor Day website, the other 7 communities are Highlands Ranch, Durango, Loveland, Windsor, Grand Junction, Westminster, and Lamar.
Heinz Bergann, Director of Alamosa Parks and Recreation, keeps track of arbor related activities and applied for the distinction. The last time Alamosa received the award was in 2003. Eligibility for the Growth Award requires a city to spend at least as much on its community forestry program during a year than it did in the preceding year and to complete several eligible activities.
Alamosa spent approximately $32,000 on Alamosa’s community forestry program in 2011. Three specific activities were cited in the application. 1) The City of Alamosa Parks Department partnered with a local Boy Scout troop, as well as with scouts attending a camporee, to manage tree issues in an area being developed as a public disc-golf course. This two-phase projected involved clean-up work and conservation efforts. The disc-golf course was Dillon Vance’s Eagle Scout project.
2) The Alamosa Tree Board, Colorado Forest Service, and the City partnered to present an all-day, tree-pruning workshop during April of 2011 presented by Colorado Forester Vince Urbina. The workshop involved an in-class session as well as a hands-on session and was well received by the overflow audience. 3) The AlamosaTrees.net website was significantly improved with tree lists and a searchable database to assist the public in selecting new tree plantings.

As a precursor to Alamosa Arbor Week 2012, Forester Urbina, who conducted the pruning workshop mentioned above, will speak on “Tree Care during Drought” at 6 p.m. on Monday, April 23rd in the Alamosa City Council Chambers. Forester Urbina is known for his well-informed and motivating presentations. The public is invited and light refreshments will be served.
As Colorado experiences one of its warmest springs and continued dry weather (with the exception of last Tuesday’s welcome snow), this topic is timely. If temperatures continue to rise, shade from trees will become ever more important.
Speaking of shade, we’ll be planting 14 trees in the newer part of the Alamosa Cemetery during Arbor Week. Please join us on Tuesday, May 1, at 4 p.m. – and if you can, bring a shovel! The “Alamosa Cemetery Shade” project is funded through a grant from the Colorado Tree Coalition and Alamosa City funds.

Cub Scout Pack 307 has generously offered to help plant trees along Sixth St. between Ross and State Streets on Saturday morning, April 28. These trees will accompany the winding sidewalk on the south side of the street. Funds for the trees were procured through a non-matching $5,000 grant from Xcel Energy Foundation and Colorado Tree Coalition.
We’re looking for volunteers to plant more of the Sixth St. trees on Monday, April 30, at 11 a.m. Please stop by and bring a shovel if you have one! Or contact me at 719.589.3295 or Marilyn@AlamosaTrees.net.
A bit of background on Tree City USA and Arbor Day. Tree City USA is part of the Arbor Day Foundation and “encourages, supports, and strengthens effective urban and community forestry programs in diverse communities nationwide through recognition, education, and publicity.”
As many people know, Arbor Day began in Nebraska. It was founded by J. Sterling Morton, originally from Detroit, Michigan. Along with other pioneers, Morton and his wife moved to the Nebraska Territory in 1854. The first Arbor Day was celebrated April 10, 1872. “It’s estimated that more than one million trees were planted that day,” according to the Arbor Day website.
“His fellow pioneers missed their trees. But, more importantly, trees were needed as windbreaks to keep soil in place, for fuel and building materials, and for shade from the hot sun.”
These conditions apply to Alamosa today!
“Trees they are our friends; They are tall, strong and leafy; They fill the earth with shade and oxygen; Trees need our protection; Let’s plant some more” by Ramona, a 5th grade student at Taft Elementary School, Idaho

by Marilyn Loser

2012 March 14

The Alamosa Department of Parks and Recreation and the Alamosa Tree Board, along with the help of volunteers like you, will plant 57 new trees this spring and summer.

Recently the “Alamosa Cemetery Shade Tree Planting Project” was funded by the Colorado Tree Coalition (CTC) for the amount of $1,500. The city will kick in another $2,000 to fund 14 trees with name plaques and protective wire mesh.  The Tree Board and Department of Parks submitted the grant. The trees will be planted this summer.

It may surprise you to hear we’re planting trees in the cemetery as we often focus on park trees. However, many Alamosans frequent the cemetery – people love to take walks in the area or just enjoy the peace and quiet in addition to visiting the graves of loved ones.

Located just south of downtown Alamosa, the cemetery provides spectacular views of the Sangre de Cristo Mountains to the East and of the San Luis Valley to the West. The older portion of the cemetery has evergreen and deciduous trees gracing the gravel avenues and shaded benches that welcome the visitor.

The City of Alamosa invested in expanding the cemetery in recent years. The city crew leveled ground, installed irrigation equipment, erected fencing, and planted lawn. However, there are few trees and the area appears very raw.

Our goal is to plant new trees that will provide future generations experiences that we now enjoy in the older part of the cemetery. The trees will be planted along the narrow avenues and will be labeled as are some newer trees in Cole Park. Wire fencing will protect them in early years from deer, lawn mowers, and other accidents.

A species-diverse variety of trees was selected from the Alamosa Tree Board approved list. The tree palette includes Lanceleaf Cottonwood, ‘Autumn Purple’ Ash, ‘New Horizon’ Elm, and ‘Cimarron’ Ash trees.

The “Beautify Bleak (6^th) Street” project will continue with more tree-plantings this spring.  The sidewalk on the south side of 6^th between Ross and State was completed last fall and we’ll plant 18 trees during Arbor Week, April 28 to May 4. The trees were funded through a $5,000 non-matching Xcel Foundation grant (through the CTC) received last year.

Sidewalk construction was more complex than you might think, so the trees didn’t get planted last year.  The Rio Grande Scenic Railroad, Colorado Department of Transportation and the City of Alamosa were all involved.

The tree palette includes ‘Autumn Blaze’ Maple, ‘New Horizon’ Elm, ‘Shade Master’ Honey Locust, ‘Canada Red’ Chokecherry, ‘Autumn Purple’ Ash, and Hackberry.

The Alamosa City Council approved and will fund yet another planting project along 6^th Street this summer. 23 trees and 37 shrubs will be planted by the city crew on the north side of 6^th south of Sonic. Blue Spruce, ‘Spring Snow’ Crabapple, ‘Prairie Fire’ Crabapple (a new variety to me), and ‘Red Twig’ Dogwood (shrub) are slated with two types of rock ground cover.

Aspen trees, donated by Loretta Mitson, were planted last spring on the south side of 6^th west of the intersection with Hwy. 285 and seem to be doing well.  The aspens are on a drip system and the city crew installed wire mesh fencing to keep the deer at bay last fall.  A few of the trees were nibbled before the fencing was in place – we’ll see how they fare this summer.

6^th Street is one of our most frequently traveled roads in Alamosa – its looks will only improve in the upcoming years!

Arbor Week 2012: Alamosa will celebrate Arbor Week from April 28 to May 4. Most of the rest of the state will celebrate Arbor Day on April 20 (the third Friday of the month).  As long-time residents of the San Luis Valley know, April weather can be problematic. Waiting a bit longer tends to be easier on the trees and planting volunteers.

The schedule hasn’t been finalized. We’ll call on you to volunteer – mark your calendar! Projects include planting trees along 6^th Street (as described above) and restoring water basins and/or bark mulch around Alamosa park trees.

We’re also hoping for local workshops on tree selection, planting, and maintenance. As a warm-up to Arbor Week, Vince Urbina, Colorado State Forester from Grand Junction, will speak Monday evening, April 23, on the topic of Tree Care During Droughts. Details to follow.

Stay tuned, I’ll post the schedule as soon as possible!

“Trees can transform a street more easily than any other physical improvement. Moreover, for many people, trees are the most important single characteristic of a good street.” Alan B. Jacobs in Great Trees

by Marilyn Loser

2012 February 29

The last Alamosa Trees column discussed applying 3 of the 7 xeriscaping (water-efficient landscaping) principles to Alamosa gardening. We’ve dealt with soil, small lawns, and irrigation systems.

Here are the remaining 4. As before, I’ll use our garden as an example.

4)      Group together plants with similar water needs: The arrangement of our yard follows the oasis approach. Plants nearer the house – the area we see and spend the most time in –receive the most water and are the lushest. I have some monk’s hood and a hydrangea. At the other end of the spectrum are low-water shrubs, such as cinquefoil, currants, lilacs and junipers that are planted further out in the graveled area of the yard and receive the least amount of water.

In between are beds with a mixture of annuals, perennials, and shrubs that receive a low to medium amount of water. Many of my annuals and some perennials reseed and have picked their own favorite spots.  For example, I have annual California poppies that have taken over an area between driveway bricks.  I never planted them there but they have done wonderfully for 10 years. Perennial columbines and penstemons pop up here and there – I haven’t had to buy new ones of these species in years.

5)      Use drought-tolerant and native plants: The idea of “native plants” is touchy.  For our area, just drive past the city limits and look around.  You’ll see sand, chico, salt grass and perhaps a four-winged saltbush.  These local “natives” are not what I want in my yard.

However, I am trying to grow more and more trees, shrubs, and flowers that are native to Colorado and New Mexico.  I have 34 native varieties in my yard.  You can check out what we grow by visiting AlamosaFlowers.net and clicking on the “Flower Lists” tab, selecting “Flower Finder”, checking the “Native to CO or NM” check box and clicking “Find Plants”.  Clicking on an individual plant in the resultant list will bring up a photo from our garden and specific plant information.

In a similar manner, The AlamosaTrees.net has a “Tree Finder” under the “Tree Lists” tab. Again click on the “Native to CO or NM” check box. I’m collecting photos of local trees for this site.

Local vendors are carrying more and more water-wise/drought-tolerant selections and can help you choose. I’m starting to add this category to both databases mentioned above.

6)      Apply mulches to retain moisture (and deter weeds): I do this in a few ways.

A: Gravel areas with plantings. I cover the areas surrounding plantings with high-quality landscaping fabric and then cover with gravel.  The fabric allows water to drain through, but retards weeds from growing up.  Remember, roots extend out quite a distance. When I first started gardening, I used plastic instead, — I didn’t realize roots grew out, didn’t get enough oxygen and didn’t benefit from precipitation. I‘ve replaced the plastic with fabric.

B: Gravel areas with no plantings. In areas, such as the vacated alley, we put down plastic and covered it with 3 inches of gravel. Since we have either gravel or mulched beds and a wooden fence, the gravel hasn’t been over blown with dirt in 12 years.

C: Shredded bark mulch.  In shrub areas and some walking paths, I use landscaping fabric covered with shredded bark mulch.  The “shredded” part is important.  The ragged edges help bind the mulch preventing it from blowing away.

D: Plant and grass clippings: In the spring, I tend to trim flower stalks left from the previous season and lightly spread them over flower beds.  This helps mitigate damage from fluctuating temperatures while allowing light through for early bulbs and ground covers.  Later in the season, grass clippings help retain moisture and thwart weeds.

7)      Regular maintenance: Any landscape benefits from regular maintenance.  I regularly walk my yard making sure watering systems are working and weeds aren’t taking over.  I allow myself time to enjoy my yard without always plucking every weed when I see it!  However, I do regular weeding, dividing, and moving of plants. Over the last few years I haven’t had to do as much. We haven’t exactly achieved a balance, but irrigation is working well, the soil is being improved, and plants are settling in.

Once, a friend said, “A weed wouldn’t dare grow here!” I wish that were true. However, regular maintenance is paying off in the long run.

We can have beautiful, water-wise landscapes in Alamosa. For more information, contact me at Marilyn@AlamosaTrees.net or visit AlamosaTrees.net and AlamosaFlowers.net.  These non-commercial sites are aimed at promoting trees and flowers in the challenging Alamosa environment.

“My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view. “  H. Fred Ale

by Marilyn Loser

I have a lawn, shade trees, and an inviting garden with gorgeous flowers – AND, I xeriscape! In the last column I outlined the tenets of xeriscaping (water-efficient landscaping). In this column, I will describe how I apply the 7 principles in my own yard. I am stepping out of my usual, trees-only context, and will discuss the entire garden. [To view images of our yard, please visit AlamosaFlowers.net and click on the ‘Our Garden’ tab.]

1) It’s all about the soil: Native soils in Alamosa are not very organic and vary from sand to clay. Plants do best in loose soil that retains moisture and contains nutrients. Water drains too quickly through sand. Clay tends to be dense and hinders roots from spreading and taking in oxygen. Further, it may not drain well enough and can cause a plant to drown. While plants create their own food through photosynthesis, they need soil nutrients to prosper.

Our yard is fairly large and originally had a mixture of sand and clay. Over the years we’ve brought in tons of top soil and compost. This may be more than you need! When starting a new flower bed, I suggest amending the top 18 inches of soil. Depending on the state of your earth, mix in top soil, compost, and/or soil enhancers.

We no longer buy soil by the ton. Last year we purchased some bags of top soil and compost from Boy Scout Troop 307. Also, I ‘sort-of’ make my own compost. I pitch vegetable kitchen waste and plant waste in a bin; then, we chip and shred it each year. I’m also a fan of Happy Frog soil conditioner.

I tend to check the soil in my flower beds every year. Most beds have a mixture of perennials, annuals and shrubs. There are a few trees also. Before sowing seeds I dig the soil to loosen it and mix in a combination of ingredients. Some wildflower seed packets say to only scratch the surface of the ground before sowing seeds. Their reasoning is that digging encourages weed seeds to sprout. However, I think seeds in my yard can’t get a good root-hold unless the soil is loose.

When I add a new perennial, I amend the soil around it. When I plant a shrub or tree, I only back fill with the soil I took out. I also top dress with soil conditioner to several feet beyond the shrub or tree hole.

2) Keep lawns small: In the last column, I mentioned that we have a small lawn near our house. I enjoy the lawn without having to spend a lot of time caring for it. When we expanded the lawn 14 years ago, I didn’t enhance the soil enough, so water drains through too quickly. We’re attempting to fix this by adding some good soil on the top each year. This year we’re going to add grass seed that
contains several varieties. We hope that one or more of the varieties will thrive with less water. Lawns are often a good place to grow a tree. If the lawn extends beyond the tree canopy, the entire root system will receive water.

3) Use efficient irrigation systems: The area closest to our house is watered by sprinklers on a timer. This includes the lawn, a tree, and a few flower beds. We use two types of low pressure systems in the remainder of the yard. One is a drip system (Netafin). The half-inch hose has emitters every foot. The emitters aren’t just holes; they have a mechanism that prevents soil from plugging the holes. Using grid networks, we water our vegetable garden and two flower beds. I believe they used this system at the Boyd Community Garden. The hoses are going strong after 14 years of being on the ground. I started out using soaker hoses but found they clogged up and were ineffective after a couple of years.

The second system uses blue-stripe tubing in which you make holes and plug in a drip cap or mini sprinkler. This type of hose is easier to modify than the emitter hose so you can lay it out in any pattern. The garden in front of Alta Fuels has this system.

When planting trees, people often make a hose loop around a tree. At first, they install a couple of emitters. As the tree grows, more emitters can be added further away from the trunk and the original holes plugged. Remember, trees need to be watered to the edge of the canopy and beyond.

The next Alamosa Trees/Flowers column will discuss the remaining four xeriscaping principles.
“To forget how to dig the earth and to tend the soil is to forget ourselves.” Gandhi

By Marilyn Loser

Wow! We just received news that the Alamosa Cemetery Shade Tree Planting Project was approved by the Colorado Tree Coalition (CTC) for the amount of $1,500.

The Alamosa Tree Board and the Alamosa Department of Parks and Recreation submitted the grant.

To some, it may seem surprising that so many Alamosans frequent the cemetery. The older portion has evergreen and deciduous trees gracing the gravel avenues and shaded benches welcome the visitor. Located just south of the main part of Alamosa, the cemetery is very quiet and provides spectacular views of the Sangre de Cristo Mountains to the East and to the San Luis Valley to the West.

The City of Alamosa has invested in expanding the cemetery in recent years.  Ground has been leveled, irrigation equipment installed, fencing erected, and lawn planted.  However, there are very few trees. The newer area appears very raw.

Our goal is to plant new trees that will provide future generations experiences that we now enjoy on a larger scale in the older part of the cemetery.

The trees will be planted along the narrow avenues and will be labeled as Alamosa did on a previous project. Wire fencing will protect them in early years from deer, lawn mowers, and other accidents. We will plant a species-diverse variety of trees from the Alamosa Tree Board approved list. These will be trees that tend to be longer-lived, more xeric, and well-suited to our environment; a wider pallete than the Siberian Elms, Russian Olives, and Cottonwoods orginally planted.

We’ll be planting 14 trees: 4 Lanceleaf Cottonwood, 3 Autumn Purple Ash, 4 New Horizon Elm, and 3 cimarron Ash trees. Stay tuned, we’ll need help planting!

By Marilyn Loser

I hear people say “zeroscaping”; I hope they mean “xeriscaping.”  Xeriscaping is water-efficient landscaping – it doesn’t mean rocks and a single cactus. It can mean beautiful yards with flowers, greenery, and shade.  In addition, it can mean reasonably low maintenance and water needs.

“Xeriscape” comes from the Greek “xeros” meaning dry, and “scape” meaning landscape.  So, the word coined by Denver Water Department employees in 1981, means a type of landscape where plants don’t require a lot of water.

The world’s first Xeriscape Demonstration Garden was created at the Denver Botanic Gardens in 1986. It has been renamed to Dryland Mesa.

We don’t have a lot of American words that begin with ‘x’. When saying xeriscape, think Xerox – yep, starts with an ‘x’, but is pronounced like a ‘z’.  I think the starting ‘zee’ sound is what confuses some people,  prompting them to say zeroscape.

To me, zeroscaping means having no plants at all – only rocks, gravel, concrete, asphalt and/or wood chips. I don’t include dirt in the list since some weeds will grow in the dirt at least part of the year.  Vince Urbina, one of my favorite Colorado foresters, says there is no such thing as zeroscaping — there will be a weed or rebel plant growin somewhere on the scene.

There are some places in Alamosa that have gone toward zeroscaping.  I understand the desire to have no yard upkeep, but it makes the property ugly.  Careful planning and planting could transform these barren scapes into a welcoming environment.

My focus has been on trees, but I plan to intersperse “Alamosa Flowers” columns with “Alamosa Trees” this spring so you’ll hear more about Alamosa garden xeriscapes.

When many of the homes in the older parts of Alamosa were built, water was inexpensive (as was gasoline). People planted lush lawns and overwatering often spilled into the streets. Alamosa water rates have steadily increased, with a big increase
happening this year. I fear people will just stop watering and our town will shrivel into ugliness.  It doesn’t need to happen!

Xeriscaping has 7 principles for growing a water-efficient, drought-tolerant landscape or garden. I will use the example of my yard to reflect on each principle.

1)      Group together plants with similar water needs: I have one area near my home that is protected from the wind and watered by sprinklers. Here I plant any plants NOT rated xeric. I have outlying areas that are very xeric and receive infrequen supplemental water.  Areas in between receive regular water and I plant more xeric plants further from water sources.

2)      Keep lawns small: Rather than a huge lawn that requires lots of water, fertilizer, mowing, and other maintenance, we have a small lawn near the house. We can walk barefoot and do cartwheels with the grandkids. It gives the sense and cooling of a lawn without having a huge expanse.  I use a hand mower. We have an ash tree in the lawn just west of the house that gets watered when the lawn does and provides welcome summer shade.

3)      Use efficient irrigation systems: We have sprinklers on timers in the lawn area and low pressure drip or mini sprinkler irrigation systems on timers on most of the rest.  For the outlying areas, I have drip systems that I only hook up every few weeks via a simple timer and hose. Local garden centers can help you with simple, easy to install systems – or you can install more elaborate systems.

4)      Amend soils to increase their water-holding capacity: The term “amend” when referring to soil may seem odd. I have a friend who says, “You amend the constitution, not the soil.” Our yard, one the west side of town did not have good soil. I have brought in top soil and soil conditioner. I’ve made and purchased compost and dug it in on a
regular basis.

5)       Apply mulches to retain moisture. As I’ve mentioned in several articles, I place 3-4 inches of mulch around each of my trees and shrubs. I mostly use bark mulch and wine corks (yep, I learned this trick at the Columbia Crest Winery in Washington state.) In the fall, I top flower stalks, leaving a few inches, and lay the cuttings over the flower beds.

6)      Use drought-tolerant and native plants: I mostly do and will go into this more in subsequent columns.  Meanwhile, check out AlamosaTrees.net and AlamosaFlowers.net to get an idea of what works in Alamosa.

7)      Stress regular maintenance: Any landscape requires maintenance.  Sometimes I see people working as hard on a weed-filled yard as they would need to keep an enjoyable yard.

For specifics on applying xeriscaping techniques to Alamosa yards and gardens, read the next Alamosa Trees column.

“He that plants trees loves others beside himself.”  Thomas Fuller

By Marilyn Loser

2012 January 18

Tree cold-hardiness is a relative term.  While researching this column I turned up articles on cold-hardy palms and bananas. I mean really, can you imagine a palm
tree in the center of Cole Park?

I consider my garden on the west side of Alamosa to be in United States Department of Agriculture hardiness zone 3 or 4 and the more sheltered downtown areas to be in zone 4. Hardiness zones are defined by climatic conditions, largely based on a plant’s ability to withstand minimum zone temperatures.  Zone 3 is listed as having minimums from -40 to -30 degrees F and zone 4 from -30 to -20 degrees F.

Also, it’s important to realize that the San Luis Valley has longer periods of cold compared to other parts of Colorado. Alamosa, Monte Vista, and Center average about 96 frost-free days a year while Colorado Springs and Denver average about 153, according to the Western Regional Climate Center.

Cold hardiness is significant, but there’s a lot more to it. A tree’s ability to 1)  endure extreme temperature fluctuations within a short time span [say from 1 to several days];
2) withstand drying, winter winds;   3) thrive at 7,500+ foot altitudes; 4) tolerate drought; 5) and grow in low quality soil is also crucial.

1)      Extreme temperature fluctuations: In the SLV, trees are usually dormant in January. However, during February and March we often have intermittent warm spells that can bring trees out of dormancy,  encouraging their sap to run and buds to begin opening up.

If temperatures plunge to freezing and cells can’t push the moisture out, they freeze and burst, damaging the tree. Buds may also freeze and never develop.  I’ve especially
noticed the damage to my forsythia the last few years as we’ve had frequent early warm spells.

Rapidly growing trees have higher internal moisture content than slower-growing, more solid wood species.  Therefore, they are usually the most severely injured in such freezes, according to Colorado State University Extension Service bulletin 7.220.

2)      Drying, winter winds: Evergreens are especially prone to this assault.  If the temperature is above freezing the tree needles try to carry out photosynthesis which releases moisture into our dry, windy atmosphere. The tree has no way to replenish the water supply from the frozen ground and dry air. Providing wind protection by screening or bundling small trees helps alleviate this problem.

Last winter was particularly dry in Alamosa.  Usually, as the soil begins to thaw in the
spring I find it moist about 5-6 inches down.  Mine was bone dry in un-mulched areas to a depth of 12 inches. Mulching the area under deciduous tree crowns with 3-4 inches of bark mulch can help mitigate ground evaporation.

3)      High altitudes: Some trees just don’t do well at our elevation.  Higher altitudes mean thinner air. Low air pressure affects human lungs; I certainly notice this when trying to scramble up a hill around here. Likewise, a tree’s vascular system is less effective with less air pressure – some species are better adapted than others.

Altitude works in conjunction with other factors and it can be hard to find altitude ranges for North American Trees.

Also, maximum altitude recommendations may be misleading.  For example, I visited one website that said Hackberries may grow “as high as 7,000 ft.”  Yet, Alamosa has several hardy specimens of these drought- and wind- tolerant trees that were planted in recent years.

4)      Drought tolerance: Given Alamosa’s water rate increase and climate change predictions of less precipitation in the southwest, this aspect is becoming increasingly
important.  “Drought tolerance” doesn’t mean these trees never need to be watered.
They certainly need regular water during the first few years to get established.  Depending on planting location and precipitation, they may need auxiliary water every year.

5)      Low quality soil: My yard ranges from sand to clay and originally had little
organic matter mixed in. In fact, I used to refer to it as ‘dirt’, rather than ‘soil’.  Arborists do not suggest just adding good soil to the planting hole. Tree roots need to extend well beyond the hole (remember, healthy tree roots extend out at least as far as the edge of the canopy and are mostly in the top two feet of soil).  Look for trees that tolerate Colorado’s alkaline soil. In addition, consider amending the soil in the entire growing area by adding compost or other soil enhancers.

Talk to the informed folks at a Valley greenhouse, garden center, or nursery, to hear their recommendations. Each year they seem to add new species and varieties that they feel will thrive in our challenging environment. Visit AlamosaTrees.net for more info.

“To exist as a nation, to prosper as a state, and to live as a people, we must have trees.”  Theodore Roosevelt

by Marilyn Loser

2012 January 4

Oh yes you can – it’s fairly easy in Alamosa!

I sometimes grumble about Alamosa’s limited tree palette. But, when it comes to identifying local trees in winter, our task is not as challenging as identifying the more than 100 species on Denver’s recommended street-tree list.

We’ll explore four clues: branching structure, bark, twigs, and nuts/seeds/fruits.

Branching structure: Take a look at a tree. How do the sub-branches grow? Are the branches opposite each other on the parent branch? Or do branches alternate up the stem? Trees with alternate branching structure include elm, aspen, cottonwood, crabapple, Russian olive, hackberry, and oak.  Those with opposite branching include ash, maple, box elder (really a maple), and dogwood (only shrubs here).

Bark: Bark is a bit trickier as young trees and branches may differ from older trunk bark. However, it’s another clue. Young aspens and new aspen growth has very white bark. There are a few birches in town and their bark tends to be less white and shaggier than aspen.

Ash bark is smooth grey in young trees and often pale grey-brown in saplings. Older trees display fissured bark with interwoven, almost diamond-shaped ridges that can resemble that of oak. Elm bark acts a bit like cork – when you press it with a finger nail it bounces back. Crab Apple bark is somewhat flaky and mottled.

Although I haven’t seen any young boxelders in Alamosa, there are a few older specimens downtown. The mature bark often has a noticeable yellowish tinge compared to other tree species. Honey locust bark is slate gray and tends to split to one side as it ages. Hackberry bark is gray and becomes very corky looking with age – the specimens I’ve seen in Alamosa are too young to have warty looking trunks.

As cottonwoods age they develop thick, brown bark divided into thick rounded to angular sided ridges. New limbs have a whitish cast while willows are more yellow or orange.

I never gave much thought to lenticels before. They are the openings found in bark that allow gas exchange between the atmosphere and the inner tissues of a plant.  As I walked around my winter yard, I noticed my young, oak-leafed ash tree has reddish bark with little white spots.  The spots are the lenticels.

Twigs: Get up closer to a tree and examine its twigs. In winter, Siberian elms are a dead giveaway.  As you look at the crown against the winter sky, you’ll notice the twigs have a zigzag structure and that there are a lot of very dark, small, round leaf buds along the stem.

As I look out my window at the ash trees in Jardin Hermosa, I can see that their limbs arch to the sky looking a bit like pitchforks.  No other trees around have that appearance.

The Kentucky coffee tree usually looks dead in winter.  We planted two in Cole Park in September 2010 and last winter I figured they hadn’t made it.  They have thick twigs and sparse branching and only tiny nubs for buds.

Natural growing honey locusts, ‘gleditsia triacanthos’, are extremely thorny, with long dagger-like, branching thorns. The thorns have three points for which it is named – triacanthos meaning three spined. It was once called the Confederate Pin tree as soldiers would use the thorns to pin their clothes together.  In cities you see more thorn less varieties these days.

Cottonwood twigs have large buds which are long and pointed, up to ½ inch in length.  They’re the longest buds I’ve seen in Alamosa. Russian olive twigs and buds are covered in dense whitish hairs, giving it a silvery appearance.

Some leaf scars (the little scar a leaf leaves when it falls off) are very distinctive.  Some are heart shaped, like the Kentucky coffee tree. Maple tree leaf scars have three dots that often look like a crescent. Ash scars have tiny dots in a row that look like little smiles.

Nuts/seeds/fruits: Often you can see signs of nuts, seeds, or fruits in winter.  I mentioned before that smashed crabapples on wet sidewalks are a hazard. You often see crabapples still clinging to trees in winter looking like shriveled cherries. My shrubby Gambel’s oak has a few acorns still attached.  However, I haven’t seen any acorns on the young Bur oaks around town.

Perhaps the most distinctive seed pods you see in Alamosa in winter are the long, spiraling pods of honey locusts.

Take a look around town.  You’ll be surprised how much winter trees have to offer. For a more complete chart of Alamosa winter tree identification features, visit
AlamosaTrees.org.

“Of winter’s lifeless world each tree Now seems a perfect part; Yet each one holds
summer’s secret Deep down within its heart.” Charles G. Stater

by Marilyn Loser

2011 December 21

Mother Nature has flocked Alamosa with hoar frost several times this December. Some mornings are foggy, but a few have our brilliant blue sky backing the white  crystalline landscape.  My heart still skips a beat as I walk around the yard and shake a tree limb that replies with a shower of glittering white. I feel I’m inside my own snow globe – you know those spherical glass worlds you hold in your hand, turn upside down, and then back upright so you can view the magical falling flakes.

Naturally, I got to wondering why we’re seeing so much and if the hoar frost damages trees. As far as I can tell from scouring the web, this type of frost doesn’t harm trees. I’ll get to damaging frost cracks in a bit.

Frost forms when water vapor freezes into ice crystals on cold surfaces. In winter, temperatures are usually low because the sun is low in the sky during the day and the nights are long. On clear nights, when there is no blanket of clouds to keep the warmth in, so any heat received during the day quickly radiates into space. The temperature drops, and frost forms when the moisture in the air freezes.

Why is frost white rather than clear if it is really ice? It is because the crystals contain air.

Have you ever looked closely at frost? We see three types of frost in Alamosa that occur in different ways, according to the Clouds R Us website.

1) Hoar frost occurs when water vapor touches a very cold surface and freezes on it instantly. This happens to the leaves and branches of plants when frost covers them with ice crystals that look like spiky fingers. Hoar frost can occur on other freezing surfaces such as soil and metal, so is often on cars. Hoar frost can occur at higher temperatures than other kinds of frost – usually when the air temperature is around 0°C (32°F). Because the ground is usually colder than air, the air must be moist for these ice crystals to form.

2) Rime frost: Rime is ice formed when a damp, icy wind blows over flowers, branches and other surfaces. Rime frost looks like icing around the edge of petals and leaves, and only occurs when temperatures are very low.

3) Fern frost: In particularly cold weather, fern frost may appear on windows. This happens when tiny water droplets (dew) first form on the cold glass.  The dew turn into ice and more moisture freezes on top.  As this process continues, more ice crystals form –  the frost develops into what looks like feathery fingers. Fern frost can create beautiful patterns of ice crystals, which often look leaf or fern like – hence the name.

The word hoar is off-putting for many people since it sounds like another word.  I found two different explanations for the term. Wikipedia says, “The name hoar comes from Old English and can be used as an adjective for showing signs of old age in reference to the frost which makes trees and bushes look like elderly white hair.”

The Landreth Seed Company offers a different explanation.  “The word  hoar is derived from a very old German word, hehr, which appeared for the first time during the early 1300’s. In those days, hehr meant sublime – the meaning today is attached to the
scientific phenomenon sublimation. Sublimation occurs when matter skips one of the three states it can obtain: gas, liquid or solid. It occurs when gases skip the liquid state and immediately become solids. We see this when dry ice ‘melts’ by forming a dense gaseous fog.” The word hehr evolved into the word hoar.

What about frosts that damage trees? Fall and spring frosts are more likely to damage trees than winter frosts.  As trees enter hibernation or leave it, liquids begin to flow within the trees and a quick, extreme drop in temperature can cause the liquid to freeze within the tree cells, causing the cells to burst and damage the tree.

In winter, trees can develop frost cracks from internal stresses in the tree trunk. Frequently, these cracks open up in coldest weather and close again as the weather warms. Ash and maple are especially prone to frost cracking. Frequently, cracks open
in the same place year after year resulting in a callus ridge (“frost rib”) down the side of the tree. As long as the tree is otherwise healthy, frost ribs do little harm.

“The sun has ‘ears’ and the stars are bright at night – Heavy frost is coming.”
“Hoar frost at night – a sunny day tomorrow.” Russian weather proverbs