Franklin Tree

Size, growth and what to expect

The Franklin tree grows slowly, about a foot a year in our growth estimator. It makes a tree of 10 to 25 feet on one trunk or several, with a crown 6 to 15 feet wide. It can flower within 4 years from seed, and ripe seed follows a year later.

It flowers from July until frost, and at its peak the tree is covered day after day with blooms. Each flower is about 3 inches across, white around a boss of yellow stamens, and sweetly fragrant. It lasts a single day. The leaves turn orange, red and purple in fall. The seed takes a year to ripen, so last year's woody capsules split in October and November.

Its only known wild stand covered two or three acres of sandhill bog near Fort Barrington on the Altamaha River. The last report of it, by the plant collector John Lyon in 1803, counted six to eight trees on less than half an acre. A census in 1999 found nearly 2,000 in cultivation in nine countries.

How to grow Franklin Tree

The Franklin tree flowers and colors best in full sun, with some afternoon shade where summers are hot. It needs an acid soil that stays moist but drains freely, since wet ground rots the roots. On heavy clay, plant it in a raised bed, and at the cold end of its range give it a sheltered spot. It suits small spaces, so it can stand 10 feet from a wall. Set trees 12 feet apart, and keep them at least 15 feet from overhead wires.

Saplings ship potted. Its roots are sparse and it moves badly, so choose the spot for good and leave the tree undisturbed. Plant it dormant, in a hole wider than the root ball and no deeper. Set the root flare at the soil line, put the native soil back in, and keep the mulch clear of the trunk. Sow fresh seed in fall, as soon as the capsules split, and do not let it dry. Barely cover it, since it needs light to sprout. For spring, keep it damp in the refrigerator for one to two months first.

Water weekly through the first two summers, since it takes drought poorly, but never keep the ground soggy. Keep a ring of mulch over the roots. Guard young stems with wire against deer and rabbits for the first few years. Prune only dead or broken wood.

A single Franklin tree sets seed, since it is self-fertile. It has a reputation for being difficult to grow, and wilt and root rot are its serious problems. The root rot, from the soil organism Phytophthora, strikes where the ground stays too wet. Never plant it where cotton once grew, since a cotton disease also attacks it.