Select Page

What Not to Do – Placing Fence Posts Within a Lawn Area

While visiting a project site last week I noticed a mistake in landscape design that I had to share:

fence post damage from weed wacker

In our landscape plans we always prefer to place fencing out of lawn areas and within landscape beds, or at least in a strip of rock.  In the photos above, these nice 6″x6″ posts are being slowly whittled away by trimmers, commonly known as “weed wackers”.

This is a condo project that was only built about 10 years ago.  I don’t blame the maintenance crews, I blame a poor landscape design.

If anything, the maintenance crews are probably cursing the landscape architect- because they have to trim around about 80 of these posts every week.

Since lawn was designed around the fence (rather than placing the fence in a strip of rock), it also gets over-sprayed by the lawn irrigation, which not only wastes water, but will quickly deteriorate a wood fence.  That’s probably why it looks like it recently had to be re-stained.

This is the official blog of Outdoor Design Group, Colorado Landscape Architects.  For more information about our business and our services, click here.

Related Posts:

Is Your Tree Next to Die? How Emerald Ash Borer Will Affect Our Urban Landscape, and What You Should Do About It


Green Ash tree killed by Emerald Ash Borer

2013 brought tragic news to urban tree enthusiasts in Colorado. In September 2013 the emerald ash borer was found in Boulder County. This find means that thousands of trees along Colorado’s Front Range could be decimated by this pest. And as Colorado State University Professor of Entomology Whitney Cranshaw tells us, the spread of the emerald ash borer (EAB) is dependent upon human activity. It is likely that EAB came to the United States via humans transporting contaminated wood crates from Asia, and it probably reached Colorado through contaminated firewood.


The emerald ash borer, Agrilus planipennis, is a beetle native to Asia. It is small, about the size of a grain of rice. Being a non-native insect in North America, it has no predators to keep its population in check. And unlike the Ash trees in Asia, our native Ash trees don’t possess the natural insecticides that control EAB. Adult borers eat leaves of Ash trees, then mate and lay eggs in crevices in the bark. The eggs hatch, releasing larvae which burrow beneath the bark, which disrupts the trees nutrient and water supplying layers. The tree becomes riddled with tunnels the larvae leave behind. The larvae then hatch in spring, burrowing their way to the surface, where they repeat the cycle of feeding on the leaves, breeding and laying eggs of new generation. They kill the canopy of the tree, limb by limb, with the entire tree dead in 3-5 years.


Adult EAB on a penny.

Colorado’s department of Agriculture estimates that there are 1.45 million ash trees in just the Denver Metro area alone.  The costs to spray so many trees will quickly mount.

Tree and insect experts agree that there is no point in spraying your Ash tree unless the tree is currently infested. “Since most EAB treatments provide control for one year or, at most, two years following application there is no benefit in treating a tree prior to when EAB is present”, Cranshaw writes in a recent report from Colorado State University.

In other words there is no treatment that will stop the EAB from attacking your Ash tree. Spraying before the tree is infested only wastes money and needlessly adds dangerous chemicals to the environment. In fact, many entomologists warn that even spraying an infested tree may have lethal impacts on beneficial insects such as bees and butterflies, and won’t completely rid your tree of EAB, and would probably only buy you a few extra years of life of an infested Ash tree.

If we take a serious look at the situation, spraying at all is mostly a futile and dangerous endeavor. Spraying gives tree care companies extra income but endangers the life of beneficial insects, could possibly have harmful effects on people and is very unlikely to ultimately save your Ash tree. As CSU’s Cranshaw has said, he expects in 5-10 years all Ash trees in the Metro Denver area to be infested by EAB.  Furthermore, Cranshaw writes: “Once established at a location emerald ash borer can be expected to survive in the area as long as any ash trees remain. Therefore some management of emerald ash borer will be required for as long as one wishes to maintain the tree”. It is our opinion that a better strategy to dealing with EAB is planning for the eventual replacement of your Ash tree, rather than treating your ash tree with toxic chemicals, year after year.

What can we do to slow the spread of EAB to the rest of Colorado?

1.)    Do not transport any ash wood in or out of your area.

2.)    Do not plant more Ash trees in Colorado.

If you have an Ash tree, you really should consider planting a replacement tree now. If you are unsure about what type of tree would be a good alternative to Ash, contact your local nursery, arborist, or contact us and we can help you with that decision.

This is the official blog of Outdoor Design Group, Colorado Landscape Architects.  For more information about our business and our services, click here.



Related Posts:

How to Tell if You Have Tall Fescue or Crabgrass in Your Lawn

Recently I had a client express frustration about his inability to kill the crabgrass weeds in his lawn.

It turns out that what he had was tall fescue rather than crabgrass.  Tall fescue is a spreading cool season grass that often appears in lawns.  It has a courser texture than bluegrass, and will sometimes “green up” in the spring earlier than the rest of the lawn.

How to Remove Tall Fescue

crabgrass vs. tall fescue closeup

Crabgrass (left) has smooth leaves that often have small hairs. Fescue (right) has ridges on the leaves.

So here’s the thing about trying to remove it:  Selective weed killers that target weeds such as crabgrass will not kill tall fescue.

The only way to remove the tall fescue is to treat it with a non-selective herbicide such as Roundup.  This type of weed killer will also kill the lawn that is directly around it.  Which means you will need to spot-seed that area, or if you have a lot of fescue you may need to remove the entire lawn and start over with seed or sod.

Should You Remove it at All?

In my lawn, I have clumps of tall fescue but I don’t like to use many chemicals on my lawn.  I just leave the clumps in place- they are hardly noticeable once the lawn greens up.

Tall Fescue in Lawn

Tall fescue emerging in a bluegrass lawn that is still dormant in early spring.

Fescues are actually pretty highly recommended as lawn grasses-  according to the Colorado State University Extension Office a fescue lawn can require up to 50% less water than a bluegrass lawn.  In fact, one of the popular sod blends we often specify for the front range is a “90/10 Fescue Bluegrass” blend.  That is, 90% fescue and 10% bluegrass.

So before deciding to use a bunch of chemicals on the fescue in your lawn, or doing a major lawn renovation – consider leaving it in place.  The fescue can be hardly visible at all from a distance, and may end up saving you money in the long term on watering.

This is the official blog of Outdoor Design Group, Colorado Landscape Architects.  For more information about our business and our services, click here.


Related Posts:

The 7 Principles of Xeriscape, Revisited 30 Years Later

By now most people in the western U.S. are familiar enough with Xeriscape to know that there is indeed no “zero” in the pronunciation (it’s pronounced more like zeer-escape).  The term Xeriscape 7 Principleswas coined by the Denver Water Department in 1981, are derived from the Greek word “xeros”, meaning dry.

There are 7 principles that make up the concept of Xeriscape:  planning and design, improving the soil, creating practical turf areas, irrigating efficiently, proper plant selection, using mulch, and maintaining the landscape.

While I am not sure EXACTLY when the 7 principles were first released (my guess is a few years after the term Xeriscape was first used), I have often wondered whether an update was needed, or if the same 7 principles would be adopted exactly the same today.

While today Xeriscape remains as relevant as ever, there are some important observations I have made through experience regarding the 7 principles, common misconceptions about them, and how they relate to landscaping in today’s rapidly changing world.  Therefore, I thought it might be helpful to revisit and add updates to the original 7 principles:

Principle #1: Planning & Design

Updates:  Planning and design is as important today as ever.  Landscapes continue to get more complex as dozens of new plant choices are introduced each year, along with advances in irrigation systems and controllers.  The more complex a project gets, the more benefit is gained from careful planning and design.

Another important development has been the landscape architecture license act of 2007, when Colorado joined the rest of the country in requiring that landscape architects be licensed, and that all commercial and large residential projects (greater than 4 units) have landscape plans that have been prepared by a licensed landscape architect.  While this may have raised the cost of design somewhat, a good efficient design will always pay for itself by minimizing surprises during construction, allowing plans to be competitively bid, and lowering maintenance costs over time.

Misconceptions:  Xeriscape can only be done in one style.  A design will make the project cost more.

Principle #2: Soil Improvements

Updates:  This is one area that needs to be looked at closer.  The intention of this principle should be to “analyze and improve soil when needed, depending on what plantings are proposed”.  The problem has been that many cities and municipalities started to require that all landscaped areas have large amounts of amendment incorporated into the soil over the entire landscaped area, and even requiring dump tickets from the contractors to prove that the amendments were placed.

While this is a good idea for bluegrass and for some types of plants, there are many other plants were the amendment is detrimental to plant health.  Many of the very xeric and native plants prefer the native, rockier soil, and can suffer from root rot if soil is heavily amended with organics.  I personally think that the amendment should only be tilled into new bluegrass areas, and in the individual planting backfill of those plants that will benefit from it.

Misconceptions:  All plants require soil improvements.

Principle #3: Practical Turf Areas

Updates:  I am not sure whether the original principle read “Practical Turf Areas” or “Practical Bluegrass Sod Areas”.  One of the trends I am seeing that we are starting to use in our designs is the creation of “turf” areas from groundcovers and/or spreading perennials and shrubs.  The questions that one needs to ask is not only where will the lawn areas be, but does an area really need to be a “lawn” at all?

Many of the bluegrass turf alternatives are very difficult and sometimes expensive to get established.  If an area of the landscape will not be used for games and high foot traffic, then why substitute a hard-to-grow lawn alternative for bluegrass when there are many good spreading plants that are easy to grow?  In other words, if a “turf” area will not be used, it simply becomes a low growing visual element, in which case many planting alternatives should be explored.

Misconceptions:  Xeriscape means no grass, and bluegrass turf cannot be used in a Xeriscape.

Principle #4: Efficient Irrigation

Updates:  Many advancements in irrigation have been made in the past several years, making it possible to irrigate even more efficiently.  However, many of these benefits have been over-hyped.  While I am all for making our irrigation systems more efficient, this approach does not address the underlying issue- how much water does my landscape REQUIRE to remain healthy?  Only by installing water efficient landscapes will any major impact be made.

Misconceptions:  If one installs new irrigation heads and a smart controller, the amount of water they will need to use will go down significantly.

Principle #5: Proper Plant Selection

Updates:  This principle goes hand-in-hand with a good design.  One of the overlooked aspects of this principle is a phenomenon known as “micro-climates”.  Microclimates are small climate differences that occur in the landscape due to sun vs. shade relationships, water availability and retention, wind, soil differences, etc.  Every day in this business I am reminded how plant selection is impacted by these micro-climates.

One area of debate is the natives vs. non-natives argument.  I am firmly in the non-natives camp.  There are some amazing native plants that I love to use, but there are also many non-natives discovered every year that meet the needs of our varying miro-climates.

Misconceptions:  Only native plants are appropriate to use.

Principle #6: Mulching

Updates:  The biggest problem I see with this principle is that all mulches are not created equal.  There are cost, aesthetic, and weight differences between wood mulch and rock mulch.  Not all plants like being heavily mulched, and some prefer rock mulch over wood mulch, for many of the same reasons some plants do not like a lot of soil amendment.  As a result, wood mulch seems to be getting a bad name for Xeriscapes.  I have even seen some cities write into code that wood mulch cannot be used for a low water-use zone.  But wood is often quite a bit less expensive than rock mulch, and is WAY easier to move around, plant in, and make adjustment to than rock.

The bottom line on mulching-  there are different rules to follow based on the type of mulch you are using.  If you use wood mulch, use a thin layer and be sure not to over-water.  If you use rock, remember that it will be difficult to add plants later or make changes to rocked areas.  Also, keep in mid the aesthetics- I feel that too much rock can make a landscape seem a little too harsh, and but having a combination of mulch types can help to visually break up large areas.

Misconceptions:  All mulch is the same, all plants love being mulched.

Principle #7: Maintenance

Updates:  This is the most undervalued principle.  For every 10 beautiful landscapes that I have designed and enjoy visiting time and again, there is at least one commercial landscape where even the most basic maintenance has been neglected.  Shrubs have been sheared off into little balls right before they were about to flower, weeds have overtaken a bed area, plants have been over-watered to death.

The biggest piece of advice I can give to property owners or managers is this:  walk your landscape once in a while, and make maintenance adjustments based on what you see.  Remember that plants are living things, and your job is to understand what will allow each plant to flourish naturally, with the least amount of interference (such as over-watering, over-pruning, etc.) while at the same time minimizing negative factors such as pests, weeds, etc.

Misconceptions:  All plants like more water, all shrubs need to be pruned, all plants have similar needs.

 This is the official blog of Outdoor Design Group, Colorado Landscape Architects.  For more information about our business and our services, click here.


Related Posts:

Should Ornamental Grasses be Cut Back for the Winter?

Ornamental grasses are more popular than ever, and for good reason.  They can add texture to the landscape, and they are tough plants that are easy to grow in a variety of conditions.  Ornamental Grasses in WinterOrnamental grasses can also add beauty to the winter landscape.

But should ornamental grasses be cut back to the ground in winter?

Most ornamental grasses develop tall seed heads late in the summer that naturally persist through the winter.  When temperatures start to drop the plant will die back, leaving the dried foliage, stalks, and seed heads.  The general rule that you should cut back the grasses before the next growing season, so that the new year’s growth will be more vigorous and healthy.

I have found a couple of exceptions to this here in the Denver area, particularly with Mexican Feather Grass (Nassella tenuissima), which did not regenerate as well or look as good the year after I cut it back.  I have since started leaving it uncut, which results is the new growth coming up right through the beautiful finely textured golden old growth.  But with most varieties, they should be cut back before new growth starts in the spring.

So the question, then, is whether you should cut them back in the fall, or wait until the spring.  Many people enjoy the colors and movement that these elements provide in winter.  Others prefer a more “neat” or formal look.

I thought it would be interesting to explore the advantages each approach:

ornamental grasses winter interest

Advantages of leaving the grasses for the winter and waiting until the spring to cut them back

  • When shrubs lose their leaves, and perennials wither to the ground, grasses can provide form in the landscape
  • Texture:  Interesting textures can stand out, collecting frost or snow, and reflecting sunlight
  • Movement:  Winter winds and soft breezes can move and sway the stems and seed heads of ornamental grasses
  • The grasses can add color to the drab winter landscape, including shades of reds, yellows, browns, and blues
  • Upright grasses can be used to help screen views when deciduous plants have lost their leaves
  • The grasses can provide habitat and shelter for birds and other small animals

ornamental grasses cut back in winter
Advantages of cutting back ornamental grasses right away in the fall or early winter

  • This can be interesting and different look, I have seen some nice formal plantings that looked stunning with the grasses cut back
  • Some grasses hold their form better than others, while some varieties may flop over under heavy snow
  • Cutting them back may give the impression (rightly or wrongly) that a commercial landscape is being better maintained
  • In some cases the grasses may block sight lines, such as to important signage in a shopping center
  • In high foot traffic areas, it may be beneficial to cut back ornamental grasses to avoid them being trampled

So what do you think, is one method better than the other?  My personal taste is to leave the grasses up all winter, but there are situations where you may want to cut them back.  And you can always decide to cut them back later, if you feel the need to tidy them up.

This is the official blog of Outdoor Design Group, Colorado Landscape Architects. For more information about our business and our services, click here.

Related Posts:

Pin It on Pinterest