JAPANESE WHITE BIRCH (Betula platyphylla japonica ‘Whitespire’)— Fran Clarke, UC Master Gardener

In the November 1998 Master Gardener Newsletter, I wrote about River Birch (Betula nigra), one of the two birches that has been found to be borer resistant. A roundheaded borer, soon to be joined by the bronze birch borer, is a major problem with other birch trees, particularly newly planted trees or ones that are stressed. The other birch that is borer resistant is the Japanese White Birch, Betula platyphylla japonica ‘Whitespire’.

The seeds were collected originally from a single tree in a native stand in the Yatsugatake mountain range, Nagano Prefecture, Japan in 1957. It has proven to be the most borer resistant white barked birch, including other seed strains of Japanese White Birch tested under drought conditions in Longenecker Horticultural Gardens at the University of Wisconsin.

The Japanese White Birch has chalky white bark marked with narrow black triangles at the bases of lateral branches. These birches are whiter than the mature European White Birches, which have extensive rough black bark patches at the base. It has a slender pyramidal form, usually growing fast to forty or more feet tall with a fifteen to twenty-five foot spread.

Contrary to what many people seem to believe, birches grow best with no competition. The Technical Advisory Committee of the Sacramento Tree Foundation recommends a minimum of fifteen feet between trees and at least ten feet from building foundations. The glossy green leaves are slightly wider and longer than the European White Birch, growing up to three inches long. They turn a clear yellow in fall. Although these trees have been available in the Sacramento area for at least fifteen years, they seem to be relatively scarce in nurseries.

The Sacramento Tree Foundation and SMUD have them available for SMUD customers. There is a group of three planted in the front yard at 5715 Carlson Drive in River Park. They were planted in February 1997 when the trees were first offered. They have more than doubled their original height and have been planted at approximately the recommended distances. Unfortunately, I do not know of any more mature specimens in accessible areas.

Let me know at (916) 924-8733 ext. 104 if you know about specimens locally. There is a grove of Japanese White Birch at the private Quarryhill Botanic Garden near Glen Ellen in Sonoma County. If anyone has difficulty finding a five-gallon Japanese White Birch, I have permission from our local wholesale grower to give out his phone number: Mike Harlan (916) 725-6461. The tree tags from the Tree Foundation trees do not have the cultivar name of ‘Whitespire’ on them, but they are grown from Betula platyphylla japonica ‘Whitespire’ seedlings. Main sources of information (pictures too!): Plants that Merit Attention, Vol. 1 - Trees and Taylor Guide to Trees.