IPM-Based Landscape Design 

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Lawns & Other Turf Areas

The following topics are discussed and illustrated below.  Click on the link to go directly to that section.

• Design Considerations
• Trees in Mown Areas
• Turf Protection Systems & Strategies
• Standards and Tolerance Levels
• Cultural Care & Growing Conditions

Also see the document on mowing strips and underlayment for further material relating to approaches that reduce overall maintenance requirements and need for herbicides in lawns and other areas where grass is kept mowed.
 

Design Considerations
 

The design of pedestrian circulation for urban facilities has an impact on turf quality.  Wear patterns in turf, created from people walking along 'desire lines', often occur when the design of the hardscape does not adequately address foot traffic.    The photos at left illustrate how 90 degree corners in sidewalks are seldom heeded.  These sidewalks should have been designed to essentially match the sweeping curve that has been created by the pedestrians. (Also note in the upper left photo how the light pedestals were designed to jut out into the lawn and have no mowing strips provided at their base.)  The top photo shows a pathway between the end of the sidewalk (foreground) and the park playground (background) that has been created by pedestrians and bicyclists along this 'desire line' (note bicyclist using path to left of playground).

	This photo represents a classic problem where a good design idea falls short when it comes to maintenance.  A series of terraces were built into this award winning public facility in British Columbia to provide places for people to gather, sit, etc.  They are approx- imately 4' x 75' each and no access of any kind was provided for bringing a lawn mower into each area.  The maintenance personnel must instead lift their mower to and from each terrace.
	Same facility as above.  The pattern of these stepping stones looks very artistic on the design drawings.  However, in execution the overall pattern goes largely unnoticed and creates a considerable amount of otherwise unnecessary maintenance (i.e., cleaning the mown grass off the pavers and routine edging).  The irregular arrangement of the primary paved area that 'blends' into the stepping stones in the lawn create many extra edges and corners that must periodically have the turf removed as it grows over the pavers. Larger pavers and a slightly less articulated configuration of them would have been better from a maintenance perspective.  Also note the tall grass around the base of the tree, which would not exist if a mulched tree well had been installed either at the time of original construction or afterwards.

Proper spacing of trees permits even large mowers to operate unimpeded.  When determining the locations of trees and other landscape features within mown areas, it is very important to consider the type and size of maintenance equipment used, especially in larger scale settings.  The mulched area around the trunks of the trees aids in the efficiency of the mowing, eliminates the need for trimming tall grass around the tree trunks, and helps prevent injury to the bark from equipment (although mulching a wider area around the trees would have been better).

This tree is placed too close to the curb if the lawn is mowed with a large mower. It could either have been placed at a greater distance from the curb or the tree well shaped to go all the way to the curb in order to eliminate the narrow strip of grass.

Trees in Mown Areas
 

Two examples of trees being panted in small groups within lawns and not providing mulched areas for them.  This increases labor for mowing and trimming and also increases the chances for equipment damage and compaction of the root system.

Tree well around small tree aids maintenance and looks good; large trees and shrubs in one bed is attractive and low maintenance.

Mulching underneath conifers where shade and soil conditions are not favorable for turf.

Examples of trees planted individually within an ornamental lawn.  The tall grass around the bases of the trees is less attractive than a mulched ring, the added requirement of trimming the grass around the trunks increases maintenance costs, and also increases the likelihood of damaging the bark and roots with epuipment.

The area around the base of this tree is sprayed regularly.  A combination of mulch, fabric, and an edging as in the photos below would minimize both maintenance requirements and the need for herbicides.

Examples of tree wells provided for individual trees.

	A tree well with landscape fabric, an edging, and mulch being installed around a young tree by two children on their school's landscape.  See the section discussing landscape fabric for more on that topic.

 
 Turf Protection Systems & Strategies
 

Installing a turf protection system to a small patch of turf that was constantly denuded by heavy foot traffic.  Fabric at base supports black plastic honeycomb which is installed level with the final grade.  Honeycomb is filled with good soil and/or plugs of turfgrass.  Years later the system is still protecting the turf from heavy pedestrian use.    Note (lower left) underlayment of a fenceline that once was a sprayed, weedy, unsightly feature.

Turf protection systems that have not provided good results.  Choice of manufacturer and installation practices make a big difference in how well such products work.  It is important to utilize good research and implementation of pilot projects to evaluate and determine optimum products and practices before wide scale applications are made.

	Moveable goal posts and bleachers allow the use of fields to be rotated easily and they facilitate mowing operations (they make it easy to cut the tall grass that grows up around objects placed on turf).  They also help prevent wear spots such as in the photo at left by periodically changing the layout of the field.

Standards and Tolerance Levels

Grasses are used in many different settings having a very wide variety of purposes, including for general use, athletic and recreational fields, visual appeal, and as a walkable ground cover.  Their overall look, the degree to which they should be maintained, and the plant species included/allowed within them is variable depending on their use and setting.  Most people's views of contemporary lawns are that they should be comprised of 100 percent turfgrass and any broadleaf plants that colonize within are seen as "weeds" and are therefore undesirable.  Indeed, there are many species of common lawn weeds that are problematic because they may tend to displace much of the grass and grow tall and unsightly.

However, some broadleaf plant species coexist quite well with turfgrass, both as volunteers seeding themselves and when intentionally planted in a lawn mix, including various perennial clovers, English daisies, common yarrow, and chamomile, and other species.  These plants are all relatively low growing, tolerate mowing and foot traffic, and do not aggressively outcompete the grass (although in some cases may eventually comprise a larger percentage of area covered where growing conditions are more suitable to them than to the grass).  The decision as to whether such plants are acceptable, tolerable, or even desirable depends on the setting, purpose, and individual aesthetic taste.

See the photos and discussion below and the section on standards and Introduction to Integrated Pest Management for more on this topic.

	English daisies have become well established in this large, general purpose lawn.  When in full bloom, they carpet the ground with a layer of white, almost as if dusted by a late spring snowfall.  This site has become a well-known and highly valued attraction on the University of Oregon campus, primarily due to the impact of the daisies in the lawn.

	These photos show a lawn mix that includes several broadleaf species and a low, clump-forming, drought tolerant turfgrass variety.  In the photos above, double, multicolored English daisies are used as opposed to the single white daisies in the preceding table.

	This is intended as a 100% turfgrass lawn that white clover has lightly spread into.  Most people would agree that this is acceptable and requires no control.
	A lawn that white clover has spread into extensively, along with false dandelion.  This can be perfectly acceptable and even desirable in many cases.  However, this particular example is at a public amphitheater where many people sit during events and the clover attracts bees.  Because some people are highly allergic to bees, city staff decided that the clover must be sprayed out due to liability concerns.
	These two photos show examples of common broadleaf weeds (top, false dandelion; bottom, plantain) that can be problematic, especially in highly ornamental and sports field turf, due to their very prostrate, large leaves that can nearly elininate the turfgrass.

“Meadow management", or "modified mowing" of little used turf areas can also reduce maintenance requirements and still provide an adequate level of care.  People like to walk, ride, or drive through well trimmed areas with “natural” areas immediately adjacent.  These sites attract wildlife and promote a feeling of proximity to nature, even in heavily urbanized areas.

Cultural Care & Growing Conditions
 

Providing good growing conditions and cultural care is very important for maintaining healthy turf that resists the development of broadleaf weeds. Turf mowing height affects the presence and development of weeds.  Tall turf (i.e., 2-3”) impedes weeds yet is attractive.  Turf is often mowed too short (<2”), creating plant stress and opportunities for weeds to develop; both conditions require intensive management to keep turf vigorous and healthy and to control weeds.    Summer irrigation is necessary in the West to maintain high quality turf - without routine watering, turfgrass goes dormant during hot, dry periods.  This situation creates opportunities for weeds to develop (many weeds are well adapted to drought conditions).

Even the best of cultural turf management programs will not provide satisfactory results when adequate soil conditions are not provided at the time of construction.  This photo shows a site where turf is growing in very compacted, rocky soil.

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