Your customer wants you to look at an oak tree that’s having trouble. Sure it has some problems; it’s been topped, the bole has mower blight, the leaves are infested with aphids, but the real problem is that it’s way too close to the house and picture window, which is probably why it was topped. You can help your customers with problems like these by focusing attention on the purpose and care of each tree on the property.

Site assessment and analysis

Any landscape, regardless of function, can be improved through site assessment and site analysis. Though more helpful when conducted before installation of plant materials, considering all aspects of the site is truly an underutilized and advantageous process.

The difference between a site assessment and a site analysis is simple. A site assessment is a documentation of the status of each plant in the landscape, as well as the observed growing conditions for them. In short, it’s the raw information. A site analysis is conducted after an assessment, taking the observations and assigning a diagnosis, value judgment or recommendation to them.

Here’s how it works: Step one is to walk the site with a clipboard, sketching in the various hardscapes (anything nonliving) and plants. As each plant is encountered, notes such as “spots on leaves,” “gash in trunk” and “stunted current season’s growth” are written on the sketch. This can be done in sections, or the whole landscape can be done all at once; there are advantages and disadvantages to each. It’s usually easier to focus on specifics when smaller areas are reviewed, while a more cohesive and overlapping view is realized when larger areas are assessed.

It’s easy to see the value of a good shade tree. Photo: John Fech

Step two is to determine the cause and seriousness of each noted concern; to make a value judgment for each. For example, a tree might be struggling because the sprinkler system has been in disrepair recently and runs for an hour and a half every morning regardless of natural rainfall. Thus, “pale leaves and stunted growth” could translate into a recommendation for an audit of the sprinkler system. It’s also possible that weather conditions have led to the infection of common pathogens, such as apple scab and anthracnose, and a treatment program to address it may be necessary.

Site assessment/analysis promotes plant health directly and prevents maladies through common sense changes in plant material. The opportunity to replace severe or moderately susceptible specimens is a good one in that it creates voids that must be filled with better-adapted plant material.

Right plant, right place

More than likely, you’ve heard the green industry catchphrase: Right plant, right place (RPRP). If it weren’t such a good guide, I’d probably stop using it. The danger associated with a phrase such as RPRP is that it can become numbing or automatic in that it’s easy to overlook the many parts involved, and skip to the two or three that are most commonly used. For example, since sun/shade and eventual height are the most referred two plant selection guidelines, the others can be forgotten or ignored, especially if a choice must be made quickly.

These RPRP components are just as important as sun/shade and eventual height:

  • Width — The other side of eventual height. Commonly overlooked, especially with small trees such as crabapple and cherry.
  • Soil moisture and pH — Trees located next to a parking lot of limestone rock are suspect for high pH soils, which usually leads to micronutrient issues.
  • Disease resistance — Disease resistance equals low maintenance, which is commonly requested by commercial clients.
  • Leaf color — In summer and fall.
  • Growth habit — Columnar, spreading, etc.
  • Flower/fruit/fragrance — Butterflies are always welcome, but bees can be a real problem, especially for home-owners, medical patients and shoppers that are allergic.
  • Native choices — Chances are good that if it’s native, it’s going to survive.
  • Hardiness zones — Cold and heat.
  • Blooming sequence — Great to have something blooming at all times; it just takes a little planning.
  • Level of maintenance — High maintenance can be tolerated in high-visibility areas, but other areas can be planted for low maintenance.
  • Color — “Wow” factor.
  • Safety — Landscape debris.

The value of a good shade tree is evident as the path gently leads toward respite. Photo: John Fech

Care guidelines by category

Screening Trees

Purpose: to block objectionable views, to provide privacy or both. Screening trees are often planted in rows along property lines. Because the primary purpose is functional rather than aesthetic, the common temptation is to choose fast-growing, weak-wooded and pest-prone species, such as poplars. Resist the urge to yield to the desire for fast growth and advise your customers to be patient and wait for sturdier choices to mature. If planted and maintained correctly for the first few years, “medium growth rate” trees will establish soon enough to serve the purpose and avoid future pest and functional troubles. In some cases, a row of large, dense shrubs, such as arrowwood viburnum, will provide adequate screening, as well.

Care: Because establishment is a large concern, proper planting depth, watering and vegetation control are important factors. The growth rate of properly mulched and watered trees will be twice as fast as those trees where these guidelines have been ignored. When pruning, achieving sufficient density to create a screen is the primary goal.

Ornamental trees

Purpose: Ornamental trees are selected to offer a special feature to the landscape, such as colorful bark or fruit in winter; interesting shape, such as topiary or cascading; or softening of harsh architectural lines, including the corners of houses. Care must be taken to avoid planting too many ornamental trees, as well as to place them within landscape beds instead of in the middle of a lawn.

Care: Proper care starts with proper placement; some prefer shade or filtered sun. Special soil requirements are also important, so soil testing to determine pH, texture and water holding capacity are essential services to provide for your customers.

Shade Trees

Purpose: The name says it all. Shade trees are put into landscapes to shield the people from the harsh rays of the sun. This is important near patios, at shopping mall refreshment stands and the bleachers of sports facilities. Shade can be heavy, light, filtered or dappled, depending on the need of the situation.

Care: Shade trees must be properly sited and given adequate room to grow and fill the intended space. Plant shade trees so that the first lateral root is at or slightly above grade. Apply 2 to 3 inches of a loose, coarse mulch, beginning 2 inches away from the trunk. Probe the soil and water when the soil is dry or becoming dry, pay special attention to the care tag or the instructions from the nursery pertaining to soil moisture; some trees prefer wet soils, while others like it on the dry side.

Framing trees

Purpose: In backyards and commercial sites where depth and perspective is needed, framing trees provide a sense of scale and focus the view. Framing trees are common on properties that are adjacent to golf courses, rivers and mountains, or where structure and order are needed in the landscape.

Care: Generally, framing trees grow large; tall and wide enough to change the perspective of the viewer. Care is the same as for shade trees.

Framing trees can highlight and direct the view of the landscape user; in this case, the Pacific Ocean. Photo: John Fech

Fruit trees

Purpose: In some residential landscapes, the owners enjoy growing their own food. Veggie gardens, small fruits and tree fruits fit the bill.

Care: Fruit trees should be established in the same manner as shade trees, but the maintenance differs greatly in terms of pruning and pest control. Overall, fruit trees are pruned to allow maximum light to penetrate to the center of the tree canopy by removing about a third of the inner wood each year. Late winter and midsummer are the best times for pruning. Unlike a well-adapted shade tree, most fruit trees tend to be pest prone, and therefore require frequent applications of pest control agents to keep pests at bay.

Windbreak trees

Purpose: Like screening trees, windbreak trees are much more functional in purpose than aesthetics. Good windbreak trees are dense in nature and hold their needles all the way to the ground. Initial spacing is a key factor in the success of a windbreak planting; spacing trees too close together will result in early wind reduction, but increase the potential for foliar disease and create competition with each other. Trees spaced too far apart result in a major delay in the desirable effects.

Care: Because windbreak trees tend to be far away from water sources, initial soaking after planting and proper mulch application go a long way towards successful establishment. Regular monitoring for foliar diseases and insects is important throughout the growing season.

Editor’s note: This article was originally published February 2011 and has been updated.