| Description | Whitespire Birch (Betula populifolia) is a medium-sized tree with chalky white bark and resistance to Bronze Birch Borer. It originated from a group of seedlings at the University of Wisconsin. |
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| Pronunciation | (BET-you-la)(plat-i-FIL-ah) |
| Plant Type | Trees Deciduous |
| Hardiness Zone | 4-7 |
| Sunlight | full sun |
| Moisture | Prefers moist to average growing conditions. In dry conditions the plant becomes stressed and this lowers it's resistance to the problems associated with Birch. |
| Soil & Site | Prefers moist, well-drained soils, tolerates average. |
| Temperature | Better resistant when grown in its northern region compared to the hot, dry south. |
| Flowers | It has monoecious (same sex) flowers that appear in early spring on the same tree in separate catkins: yellowish-brown male flowers in single catkins (up to 4 inches long) at the branch tips, and greenish female flowers in smaller, upright catkins (up to 1/2 inch long). Female flowers are followed by drooping, cone-like fruits that contain many small, winged seeds, maturing in late summer |
| Fruit | catkins |
| Leaves | Simple, alternate, glossy dark green, and doubly serrated. |
| Stems | The bark is chalky white and doesn't exfoliate. |
| Dimensions | Reaches 20-25 by 30-40 feet and is narrow to pyramidal. |
| Propagation | The most resistant plants must be clones of the original plant. Seed-grown plants may lose of the desired resistance. |
| Cultivar Origin | The original seed was collected by John L. Creech in 1951 in Japan. Seeds were grown, and one was chosen by Dr. Hasselkus of the University of Wisconsin as the best form with resistance to the Bronze Birch Borer. The original tree is still alive at the university's arboretum (as of 2015). Whitespire was originally classified as a cultivar of Betula platyphylla var. japonica when introduced to the market in 1983, but that name was later changed when it was confirmed that 'Whitespire' is actually a gray birch, Betula populifolia. |
| Misc Facts | Plants propagated by cloning rather than by seed are often referred to as Whitespire Senior Birch. |
| Author's Notes | It's best to purchase Whitespire Birch Senior since it is vegetatively (asexually) propagated and will have the desired traits. Seeds produced from plants will have mixed traits. |
| Notes & Reference | #93-North American Landscape Trees (Arthur Lee Jacobson), #144-Missouri Botanical Gardens website (www.missouribotanicalgarden.org), #154-Dirr's Encyclopedia of Trees and Shrubs (Michael Dirr) |
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