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Betula nigra Dura-Heat™,
Dura-Heat Birch

The cultivar name is 'BNMTF' and is trademarked Dura-Heat™. Reported to be a Florida seed source. Foliage is smaller, closer together on the twigs, thicker than the species, and is more persistent in fall. The trees I have seen appear more dense than the species, yet they grow at a very rapid rate - faster than the cultivar Heritage™ in the south. Foliage is smaller and more leathery than Heritage™. Root system is reported by growers to be densely branched and compact. Trees can transplant in summer, even in the deep south, without problems provided irrigation is present. Birch pollen causes significant allergy in some people but pollen is produced for only a short period and in small amounts.

Tree occurs naturally throughout northern Florida south to Alachua County.

River birch is very susceptible to damage from ice loads. Trees cast light shade under the canopy making it easier to grow turf under the tree than under other trees with a denser canopy. Bark in the shade may not generate the light color that is considered so attractive. Birches in containers tolerate moderately-high soil salt solutions up to about 6 mmhos/cm according to the saturated media extract method. Birches are difficult to grow in containers in Florida.

It is very well-suited for planting along steam banks where it is native and in other areas which are inundated for weeks. River birch tolerates low soil oxygen, flooding, and clay soil but needs moist conditions. The tree requires an acid soil, otherwise it becomes chlorotic. River birch is hardy, grows rapidly, but the species tends to be short-lived (30 to 40 years) in many urban settings, possibly due to inadequate water supply. Situate the tree so it receives adequate water. Large trees are prone to trunk decay. Not a tree to plant and forget due to irrigation requirement.

The tree is not as susceptible to bronze birch borer as are other birches. This cultivar may be better adapted to the heat than the species in USDA hardiness zone 8b, possibly 9a and 9b, if provided with irrigation and plenty of soil space. This cultivar has glossy foliage and the bark exfoliates sooner than the species. May be more tolerant of the heat in the southern portion of the US, especially in the southeast.

Wood is considered diffuse porous meaning that there is little difference in size of pores between spring and summer wood. Birches are considered poor compartmentalizers of decay. This means decay can develop and spread quickly following mechanical injury from construction activities near the tree, vandalism, storm damage, or improper pruning cuts. Plants serve as hosts for butterfly larvae. Seeds are attractive to birds including goldfinch and red poll.

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