by Todd Rutherford
When it comes to trees in designed landscapes in Colorado, landscape architects and designers don’t have very many species to choose from. With that being said, it might seem heretical to propose that the list of trees to pick from be restricted even further. Specifically, I advocate that large evergreen trees NOT be planted in dense urban areas that experience cold winters, unless they are sufficiently distant from walks and streets located north of such evergreens.
The shadows that large evergreen trees cast can help foster ice patches on walks and roads, compromising the safety and welfare of those who utilize these areas to travel about our towns and cities. If we are going to encourage biking and walking to ease automobile congestion and alleviate environmental impacts, having the safest travel routes we can achieve is a noble goal.
It may be surprising to those who don’t work in the landscape, architecture or planning fields, but many municipalities require that a certain number or percentage of the trees on a landscape plan be evergreen trees. Sometimes these arbitrary requirements restrict designers and architects to squeeze these large winter-shading ice patch-makers into a site where it might be best to avoid them. However, I should mention that some municipalities that I’ve worked with do acknowledge the problem of winter shading from evergreen trees, and they do have instructions in their landscape codes to locate proposed large evergreens away from walks and roads that would be shaded by those evergreens.
I first became aware of the problem of evergreen shadow ice patches as an urban bike commuter in the Denver area. It is frustrating at best, and rather dangerous at worst to encounter a patch of ice on a street during winter time. I have found that often times when biking in the Denver area in winter, the majority of streets can be clear of ice, except for those areas shaded by evergreens that are located just south of walks and streets. But it is not just bikers that would benefit from restricting evergreen trees in urban areas. Walkers and runners would also have an improved level of travel safety due to less icing of their pathways.
An ice patch on a Denver street, from the shadow of a large evergreen tree.
Because the foliage canopy of pine, spruce and fir trees does not drop during winter, melting of snow and ice via solar gain is limited. Deciduous trees, which drop their leaves and allow more sunlight to reach walks and streets, are a better choice in place of evergreens. I acknowledge that evergreen trees are often used for landscape screening. But I question whether this screening is worth it when considering their impact to roads and walks during winter.
Another impact from lost solar gain due to evergreen tree shading is on homes and other buildings. A building that sits in the winter shadow of a large evergreen tree will miss out on solar warmth during a sunny Colorado winter day.
I do realize that in dense urban areas, it’s not just trees that can shade our streets and sidewalks. People need shelter and workspaces, and some of those structures could end up shading streets and cause ice patches. But residents don’t need evergreen trees on their urban lot. I advocate for trees to create shade in summer, visual interest in all seasons, and wildlife habitat. But the choice of tree in tight urban quarters needs to be considered carefully.
Despite the tongue in cheek title of this blog post, evergreen trees can be a wonderful addition to the landscape. I am not actually asking for evergreen trees to be banned from urban areas of Colorado. However it does seem best that in dense urban areas that experience cold winter weather, we should consider restricting evergreen trees to parks and large lots, away from streets and sidewalks where their winter shade will not cause icy travel dangers for walkers, bikers and even cars.
This is the official blog of Outdoor Design Group, Colorado Landscape Architects. For more information about our business and our services, click here.
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by Matt Corrion
The landscape design includes patio space and a gas fire pit that allows easy enjoyment of the mountain views
Are you considering purchasing a new home? When you tour the lot, examine the adjacent views and how the site may be landscaped and used for outdoor living space. With a little foresight and a good design, the yard can be made into an inviting extension of your home for your family and guests alike.
For this project, located on the west side of Arvada, Colorado, we worked with the homeowners to take advantage of amazing mountain views, while adding value and convenience to their property. A sloped lot was redesigned to provide a flat lawn area and a secondary seating area with a custom gas fire pit. Pavers were used to soften the existing covered concrete patio, and a built-in outdoor kitchen and bar seating were added. Soft lighting provides security and ambiance in the evening, while the Rocky Mountains provide the backdrop for stunning sunsets.
The view from the back of the lot toward the house and outdoor kitchen
View of firepit with tiered lawn behind
The view from the leveled-off lawn are to the outdoor kitchen
The existing sloped backyard
Most builders will include a basic front yard landscape in the home price, but will leave the back yard as bare ground for you to improve however you wish. The design must be approved by the homeowners association. The proposed landscape will need to ensure proper drainage and shouldn’t have any negative impacts on your neighbors lots, or adjacent open space.
The front yard can always be redesigned as well. The front yard irrigation mainline and valves should already be in place, so the design can be modified pretty easily. This homeowner asked us to redesign the front yard simultaneously, and they plan to redo the front yard in a second phase. For the time being, they have completed their landscape, eliminating the bare dirt and allowing them to fully enjoy their new home and yard.
Pavers were installed over the concrete patio that came with the home
Enjoying a beer and the mountain views
This is the official blog of Outdoor Design Group, Colorado Landscape Architects. For more information about our business and our services, click here.
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by Todd Rutherford
As we move further into the fall season, many gardeners have turned their attention to cleaning up and preparing to put their gardens to bed for winter. Gardeners should also take this time to plan ahead for spring blooming bulbs which are currently available in your local garden center. Now is the perfect time to add these must-have jewels to your landscape. For most areas in Colorado, you should plant these bulbs sometime between the middle of September to the end of October. I have planted bulbs as late as November during a mild fall and winter. As long as the ground is not frozen, you can plant bulbs. However, by planting in early fall you give the bulbs time to establish some roots before the soil freezes, ensuring the best success. Lucky for us, the growing conditions in much of Colorado are perfect for spring blooming bulbs. The climate and ecological conditions of many of the bulb’s native ranges are quite similar to our high plains region.
Crocus popping up through veronica and sedums.
The diversity of size, shape and color of spring blooming bulbs is fascinating. Some of the best bulbs to plant in our area are (listed in order of bloom time) :
Early Spring Bloomers: crocus, Siberian squill, snowdrops, dwarf iris, and species tulips
Mid-Spring Bloomers: hyacinths, daffodils, grape muscari, fritillaria and tulips
Late Spring Bloomers: alliums, irises and fox-tail lillies
Alliums with Cholla cactus.
Fall planted bulbs do best in soils that are well drained. If the soil is too wet, the bulbs may rot. The rule of thumb is to plant the bulbs at a depth 3 to 4 times the length of the bulbs. If you buy bulbs in a package, a visual guide to bulb planting depth is usually printed on the package.
Consider adding “bulb food” to the holes you’ve dug before you drop in the bulbs. Phosphorus fertilizer will give your bulbs a boost, and help them become established. Traditionally a product called “bone meal” was recommended for providing phosphorus to bulbs. But research done at Colorado State University has shown that product doesn’t work well in our typically alkaline soil chemistry. Consider a conventional (a.k.a. “non-organic”) fertilizer called “triple super phosphate”. However, using phosphorus from conventional fertilizers has been linked to environmental damage such as toxic algae blooms in lakes and rivers. Use the conventional phosphorus sparingly and carefully. If you’ve not already done so, amending your soil with compost is also a good idea to improve soil texture for your bulbs.
Close up of foxtail lillies.
Most spring blooming bulbs do best in full sun to part sun locations as opposed to deep shade. But if the site is south facing in full sun, that area’s soil may warm up too much in late winter, causing the bulbs to flower early and those blooms would be susceptible to frost damage during cold snaps. It is a good idea to mulch the soil where you’ve planted the bulbs. Mulch will keep the soil from drying out, and help moderate soil temperature so it doesn’t warm up too quickly.
Design-wise, you can tuck just a few bulbs into niches between established perennials and ornamental grasses in your garden, or you could add large groupings of one type of bulb to get maximum color punch in your landscape. One effective way to add bulbs to an existing garden is to place them around low-growing plants that will still be dormant when the spring bulbs emerge. That approach is particularly effective with low growing groundcover perennials. Some people will add early spring bulbs such as crocus or snowdrops to a lawn area, knowing that the grass won’t start growing or need a mowing until after the bulbs are done. And if you want to add bulbs year after year, you might want to make a plan or take photos of where the existing bulbs are when they are blooming. That way you can avoid disturbing the established bulbs next time you add more in the fall.
Tulips mingling with veronica and the remnants of last year’s ornamental grass.
For all the bulbs, you should not remove the leaves after the flowers have faded, until the leaves have turned from green to brown. Removing green leaves too early deprives the bulbs the ability to feed themselves in preparation for the next year’s blooms.
If your bulbs are “happy” where you’ve placed them, there’s a chance they will supply you with gorgeous blooms for many years. Adding spring blooming bulbs to your garden is an easy way to get dependable spots of color into your landscape for a springtime show!
This is the official blog of Outdoor Design Group, Colorado Landscape Architects. For more information about our business and our services, click here.
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by Todd Rutherford
Starting on August 10, 2016, it is no longer illegal for homeowners to collect the rain (or other precipitation) that has fallen on their roofs. In May 2016 Governor John Hickenlooper signed a law (House Bill 16-1005) that allows residential properties and multifamily residences with four or fewer units to use up to two rain barrels, located above ground, with a combined storage capacity of 110 gallons.
Rain barrels can only collect precipitation from rooftop downspouts, and the collected water can only be used on the same property from where it was gathered. The collected water can only be used for outdoor purposes, such as watering outdoor plants. Collected water in rain barrels can not legally be used for drinking or indoor uses. Additionally, it should be known by rain barrel owners that operating a rain barrel does not constitute a water right. There is language in the bill that the State Engineer “may curtail rain barrel usage” if a water right holder can prove that the use of rain barrels has impacted their ability to receive their entitled water. In fact, in the bill it says the State Engineer must report to agricultural committees in the legislature in the year 2019 and 2022, on “whether the allowance of small-scale residential precipitation collection pursuant to this article has caused any discernible injury to downstream water rights.”
If you would like to learn more about rain barrels. check out Colorado State University Extension for more information.
This is the official blog of Outdoor Design Group, Colorado Landscape Architects. For more information about our business and our services, click here.
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by Todd Rutherford
I took this photo of a Firecracker Penstemon (Penstemon eatonii) in my garden back in early June. We here in the Denver area were enjoying spring like weather at the time, and so the vivid red blooms of this beauty were still captivating the pedestrians in my neighborhood who passed it by. Despite its namesake, these blooms do not make it to July 4th, as this plant usually begins flowering in early to mid Spring. Behind the penstemon, you can see a blue salvia providing a lovely blue-purple counter note to the penstemon’s brilliant warm red. This particular plant is looking a little leggy. The bed where it resides gets a bit more moisture than the plant should be receiving. It is my understanding that many (if not most) of the penstemons do better on the drier side. For useful information on how best to care for penstemons, please see the list of penstemon growing tips on the High Country Gardens website. One characteristic I appreciate about Firecracker Penstemon is the foliage can be evergreen throughout our Denver winters. And, if you have hummingbirds visiting your yard, they might be happily feeding on the tubular flowers this gorgeous plant produces.
I started this plant indoors, from seed. Many of the penstemons are very easy to acquire this way. This ease of starting from seed obviously translates to the the plants reseeding themselves in the garden. However, I find they are only mild re-seeders, and not nuisance re-seeders like lamb’s ear or blanket flower.
I highly recommend you add a splash of red to your landscape with Firecracker Penstemon. If red is not the color you are after, there are several other penstemon species and hybrids to choose from that offer diverse flower colors on plants that are perfect for low-water landscapes.
This is the official blog of Outdoor Design Group, Colorado Landscape Architects. For more information about our business and our services, click here.
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