Adequate space for crown development is an important requirement for these trees. Most important is enough space for their roots to grow. Roots are responsible for water and mineral element intake, energy storage, the synthesis of important organic compounds, and a firm anchor for the tree to stay in place.
Plant growth is energy-dependent, and through the process of photosynthesis, leaves of trees and shrubs get light energy from the sun and convert it to carbohydrates (starch and sugars). If the plants are not accommodated with enough light, they will very likely die.
An adequate amount of water is essential for plant growth. Either insufficient water or too much water are the primary causes of death for newly-planted trees.
The atmosphere that surrounds above and below-ground portions of landscape plants is generally taken for granted. But growth cannot occur without oxygen which is essential for respiration, and carbon dioxide which is required for photosynthesis.
Plant growth also can be limited by growth-inhibiting substances that contaminate the air. The major air pollutants are sulfur dioxide; ozone; fluoride; peroxyacyl nitrates; oxides of nitrogen; and particulates such as cement kiln dusts, lead particles, soot, magnesium oxide, iron oxide, foundry dusts, and sulfuric acid aerosols. The best way to prevent injury from atmospheric contaminants is to use pollution resistant plants in areas where known or potential pollution problems exists.
After absorption by the roots, mineral elements are taken to various parts of the plant for utilization. There are sixteen mineral elements essential for normal plant growth and they are usually classified as macronutrients (hydrogen, carbon, oxygen, nitrogen, potassium, calcium, magnesium, phosphorus, and sulfur) or micronutrients (molybdenum, copper, zinc, manganese, iron, boron, and chlorine), according to their relative concentration in plant tissue. Throughout a plant's life, mineral elements are required for growth and maintenance, however, all plants do not have the same mineral requirements.
Adding mineral elements through fertilization is an important cultural practice that contributes to plant health. But don't give too much, it could lead to salt build ups in your soil!
Soil reaction, expressed as pH, refers to the acidity or alkalinity of a soil or the relative proportion of hydrogen (acid) and hydroxide (alkaline) ions. Equal concentrations of the two produce a neutral reaction (pH 7.0). As a soil becomes more acid, its pH decreases; as it becomes more alkaline, its pH increases.
The availability of a number of mineral elements, particularly phosphorus and the micronutrients, is directly influenced by soil pH. Most plants will tolerate a wide range in pH (5.5 to 8.3), particularly if the soil is well drained, but a soil ph between 6.0 and 6.5 is thought to be best. Soils having pH levels well above 7.0 can be successfully treated with elemental sulfur (96%) to lower soil pH and improve plant growth, however, a better solution might be to use plants that in nature are associated with alkaline soils.
Good website with information of the three major types of Coniferous Trees Including soil requirements.
Temperature extremes, both high and low, can result in injury or even death to your trees, so you need to be very mindful of your outside surroundings. High temperatures are unfavorable for the growth of many landscape plants because their rate of photosynthesis begins to decline rapidly after a critical high temperature is reached. Unfortunately for trees, respiration is not quite as sensitive to high temperatures, and continues day and night, further depicting food reserves. Finally, high temperatures may simply cause severe water loss when transpiration exceeds moisture absorption by the roots. Even roots can be injured by high root-zone temperatures.
Low temperatures also can present problems for landscape plants. Most of our trees tolerate a certain amount of freezing in branches, trunks, and in some cases leaves, after undergoing a seasonal change in metabolism known as acclimation. Cold-hardy plants that have entered this quiescent or dormant state are usually capable of tolerating severe cold. But low temperature injury may occur:
(1) when temperatures fall below a plant's maximum cold hardiness limit, even after normal acclimation has occurred;
(2) when premature freezing occurs before the plant has acclimated in the fall;
(3) when unusually late freezes occur in the spring after the plant has deactivated; and
(4) when there are dramatic swings in temperature during the winter that cause the plant to deactivate before the threat of severe freezing is over.
In any discussion of cold hardiness, it is important to remember that plants are made up of many different organs and there can be significant differences in hardiness among them. Roots, for example, are much less cold hardy than branches. But there also can be differences in hardiness among above ground parts of the plant. For example, flower buds are usually much less cold hardy than vegetative buds. Therefore, a plant's ability to tolerate both high and low temperatures must be a prime consideration when selecting it for a given landscape situation.