Uniquely Different Franklinia Tree

Franklinia at NC Arboretum in Asheville, NC

Franklinia (Franklinia altamaha) is a U.S. native large shrub or small tree to 10-25 feet tall. Rated hardy in USDA hardiness zones 5-8, the tree seems best suited in zones 6 to 7.

Success with growing franklinia depends on purchasing a quality nursery plant, proper siting, and care, particularly during the first 2-3 years. Franklinia is only available from e-commerce nurseries and is best planted from late winter to early summer.

The species was first discovered growing in 1765 growing along the banks of the Altamaha River in southeastern Georgia by botanists John and William Bartram. The tree has been extinct in the wild since 1803. All franklinia trees are descendants from seedling propagated by the Bartrams in their Philadelphia, PA garden. Franklinia belongs to the tea family (Theaceae) and is closely related to Camellia, Stewartia and Gordonia (loblolly bay). The tree was named to honor Benjamin Franklin.

The tree’s most striking feature is its showy 2 – 3 inch pure white flowers with clusters of golden yellow stamens in the centers. Franklinia’s camellia-like flowers appear from late summer until frost. The blooms are sweetly-fragrant upclose.  Narrow, oblong-obovate, glossy dark green 3-5 inch long leaves turn several shades of orange, red and purple thru the autumn season. Branching is upright and spreading to create an open airy appearance. Ridged grey bark with prominent vertical white striations adds slight winter interest.

Franklinia grows best grown in humus rich, medium moisture, moderately acidic (pH 5.0 - 6.2) and well-drained soils and in full sun (in North) to partial shade (in Southeast). Franklinia prefers sites similar to azaleas and rhododendrons.

Fertilize in early spring with an acidic based soluble fertilizer such as Miracle Gro®, Miracid®, or Hollytone®. Franklinia also favors an annual feeding of Epsom salts (magnesium sulfate) @ 1 Tablespoon per gallon of water per tree.

Franklinia is valued as a specimen or a collector’s tree. Wilt and soil root rot (Phythoptera) are the serious problems. Proper siting of this unique tree is absolutely crucial. It is notoriously finicky to transplant because of its sparse fibrous root system.

Korean Sweetheart Tree

Bright Red Fruits of Sweetheart Tree

The late Dr. J. C. Raulston, N.C. State University horticulture professor emeritus, discovered Korean sweetheart tree in 1985 on the Korean Peninsula while participating in a U.S. National Arboretum collection expedition. 

Dr. Raulston brought seeds back to the N.C. State Arboretum for assessment and evaluation. The common name "sweetheart tree" was coined by Tennessee nurseryman Mr. Don Shadow.

The tree prefers a sandy or medium loamy soil and full sun to partial shade. Once established the tree tolerates brief dry periods lasting 4-5 weeks, and is at its best in soils with consistent and even moisture. Provide supplemental irrigation in regions where summers are exceptionally hot and dry.

Opposite pinnately compound leaves measure 6-10 inches long. The fruits are major asset for this small growing tree/large tree. In late summer showy clusters of heart-shaped fruits ripen from green to pink to red. In early to mid-October the fruit capsules split open to reveal a tiny, shiny, black seed.The grayish colored bark has white striations which adds some winter interest.

No serious disease and insect problems trouble this small 25-30 feet tall tree. Availability is primarily from on-line plant nurseries