Soil pH or level of acidity/alkalinity is a critical soil condition that needs to be considered when selecting trees and shrubs for planting.  Many trees are adaptable to a wide range of soil pH levels, but a few species are sensitive to high or low pH levels.  This sensitivity can have a detrimental effect on the long-term health of the plant.

Most woody plants will grow in a pH range from 5.0 to 6.5.  High pH levels or alkaline soils that range from 7.0 to 8.0 and above have the greatest impact on the health of some sensitive species.  This usually results in a nutrient deficiency in the plant that appears as chlorotic foliage or foliage that appears dull green or yellowish.  Iron deficiency is the most common problem.  The deficiency occurs because at high pH levels Iron becomes immobile in the soil and cannot be taken up by the plant.

Problems generally only occur when sensitive plants are planted in soils outside their pH tolerance range or when extreme pH levels exist.  Other environmental stresses may contribute to the problem such as compacted, infertile or poorly drained soils.

It is important to know your soil's relative pH level and soil properties when selecting species to plant. This will reduce the complications from the right plant in the wrong site. Use the following links to help you match the plant to the site.

Favored Soil pH for Native Trees

Favored Soil pH for Shrubs

Favored Soil pH for Non-native Trees

This list is not all encompassing so research any plants not listed here.  Remember plants are living organisms and as such do not always respond in predictable ways.  One plant may thrive where it shouldn't and another may die in ideal conditions.