The Soil Requirements for a Japanese Blueberry Tree
The Japanese blueberry tree (Elaeocarpus decipiens) is a broadleaf evergreen tree capable of reaching heights of 60 feet, with a spread of up to 40 feet. The tree is characterized by small, urn-shaped white or green flowers and blue fruits. Japanese blueberry tree is tolerant of a range of soil conditions, though it favors rich, fertile soil. Chlorosis, in which the leaves turn yellow, is common in poor growing conditions.
Japanese blueberry trees are more tolerant of neutral to slightly alkaline soils than similar evergreen trees. That being said, the tree will look its best in a well-draining, rich soil. The tree has a tendency to develop chlorosis in soils that have exceedingly high pH or that are too compacted. Soil drainage can be improved by mixing organic matter such as leaf mold into the soil. Organic matter can also help retain moisture. The tree does not like sandy soils.
During the tree's first growing season, water regularly to keep the soil moist and help the tree establish a healthy root foundation. Trees should be watered at least once a week during summer dry periods and twice a week during extreme heat. Once the tree is established, Japanese blueberry is moderately tolerant of drought. Apply a general-purpose fertilizer annually in the spring to improve the soil and give the tree the boost it needs to produce new foliage.
The Japanese blueberry tree is susceptible to chlorosis, a condition usually caused by a lack of nutrients in the soil. Symptoms include leaves lightening in color or turning yellow. In severe cases, premature leaf drop and branch dieback may occur. Dry conditions combined with chlorosis can result in serious leaf scorch. A lack of iron in the soil is often the cause of chlorosis, as iron becomes difficult for the tree to absorb if soil pH goes above 6.5. Foliar sprays that contain iron can be beneficial in helping the tree maintain its green color.
Japanese blueberry requires plenty of space to spread out. If crowded with weeds and other garden plants, the tree is forced to compete for nutrients in the soil. This can be especially detrimental in young trees that are struggling to get established. Apply a thin layer of mulch to the soil to help retain moisture and suppress competitive weeds. If you don't have enough space to accommodate Japanese blueberry, try one of the more manageable dwarf Japanese blueberry cultivars such as "Little Emperor."
Michelle Wishhart is a writer based in Portland, Ore. She has been writing professionally since 2005, starting with her position as a staff arts writer for City on a Hill Press, an alternative weekly newspaper in Santa Cruz, Calif. An avid gardener, Wishhart worked as a Wholesale Nursery Grower at Encinal Nursery for two years. Wishhart holds a Bachelor of Arts in fine arts and English literature from the University of California, Santa Cruz.