What are the plant’s site conditions?

What are the plant’s site conditions?

What do u see on other plants? leads directly to a more focused examination of the site in which the plant is growing. A few key site characteristics can include everything from soil characteristics and exposure to sun and rain, to construction history and competition from other plants.
The soil type relative to drainage, extent of compaction, amount of organic matter, and acidity/alkalinity can tell a great deal about the success and failure of various plants. Poorly drained soils with poor internal aeration sooner or later result in death of Taxus.

Acid-loving plants often develop yellowing between the veins (or to put it more stuffily — interveinal chlorosis) if growing in alkaline soils (pH above 7) due to iron deficiency. This can be diagnostically investigated by using soil tests and even plant tissue analysis, or by simply looking at the plants on-site. If you notice rhododendrons, birches, white pines, and other acid-loving plants thriving in a location, then a diagnostician might suspect the yellowing of leaves on the similarly acid-loving pachysandra is due not to iron deficiency, but rather to other factors such as overexposure to sun.

Sun and shade exposure is also critical to the success of many plants. Japanese maples tend to thrive in protected sites, developing physiological leaf scorch in hot, sunny areas. Flowering dogwoods generally do poorly in open, hot sites (and often develop borer problems if stressed) and also in densely shaded sites where diseases, such as dogwood anthracnose, are favored. Partial shade is best for flowering dogwood.
Exposure to wind can result in desiccation of leaf tissue of broad-leaved evergreens such as rhododendron in winter and should be considered while diagnosing these plants and the extent of wind exposure. Even exposure to rain can be an important clue. Diagnosticians often miss the implication of overhangs from houses when wondering why herbaceous ornamentals near structures seem to be languishing despite adequate recent rainfall.

The effects of construction are also a factor that should be investigated relative to the site. How much soil grades were raised, the effects of bulldozers on soil compaction and root destruction, installation of sewer lines, driveways, roads, and structures all play a role in plant health, often many years after the fact. Diagnosis would be easy if raising the soil grade  6 inches during construction activity caused trees to fall over within a week or two.

The truth, however, is that this kind of stress on root systems, due to reduced oxygen concentrations for the now-buried roots, can have effects for years from the contribution to overall plant stress. Nailing down exactly how much damage is due to various factors is difficult — if not impossible — to pinpoint, but it is the job of the diagnostician to put it into as clear a perspective a possible.

Always keep an eye on plant selection when assessing site conditions. It is very difficult to modify the site once a plant is planted. In cases where it’s “wrong plant, wrong site,” your recommendation may be to replace the plant. Good plant health management means starting with the right plant in the right place.