Kentucky Coffeetree

(Fabaceae [also known as Leguminosae] - Pea Family)

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• Form
  • large shade tree
  • maturing at about 70' tall by 50' wide, although specimen trees in open areas can get much larger
  • upright irregular growth habit in youth (often being gangly, sparsely, and coarsely branched), but becoming upright oval to upright rounded and symmetrical with maturity
  • rapid growth rate in youth, slowing to a medium growth rate with maturity

• Culture
  • full sun to partial sun
  • prefers continuously moist, rich, deep soils in full sun, but is very adaptable and urban tolerant, especially to heat, drought, very alkaline pH soils, soil compaction, and wet sites
  • propagated primarily by seeds, but also by rooted cuttings (which can be selected from a male tree if fruitless character is desired, or a female tree if fruiting character is desired [as long as a male tree is nearby for pollination])
  • Pea Family, with no serious disease or pest problems
  • moderately available in ball and burlap form

• Foliage
  • alternate, bipinnately compound and very large, up to 3' long by 2' wide
  • leaflets emerge deeply bronzed, quickly turning to medium green and then dark green or blue-green by mid-Summer; each leaflet about 2" long, ovate, arranged in alternate fashion along the pinnae, with 3 to 7 pairs of pinnae arranged in opposite fashion along the huge rachis
  • the rachis (with its swollen base) persists on the tree during early Winter, after leaflet and pinnae abscission, but leaves behind a huge leaf scar upon abscission
  • fall color is usually chartreuse and ornamentally poor

• Flowers
  • inflorescences occur in late May and early June, but are often hidden amongst the expanding foliage
  • staminate (male) and pistillate (female) inflorescences either occur on separate trees (dioecious) or a mixture of unisexual (male or female) flowers and bisexual (perfect) flowers occur on the same tree (polygamo-dioecious)
  • female inflorescences are up to 10" long and pyramidally shaped, with the males about one-third as large, both having green-white to blue-white flowers and rather fragrant (but not noticed due to the height of flowering branches on mature trees)

• Fruits
  • 8" long and 0.75" thick, bold-textured purplish-brown stout pods mature in Autumn on female or polygamo-dioecious trees, containing seeds (with a very hard seedcoat) embedded within the sweet and sticky pulp of the fruit
  • the pods dessicate and persist in pendulous clusters from stout branches throughout much of the Winter, with abscised fruit litter being a maintenance chore to clean up in late Winter and early Spring
  • heavy fruit crops are not borne every year
  • brown seeds were roasted or boiled and used by the early American pioneers as a coffee substitute, hence the common name
  • be aware that the raw leaves and raw seeds (but it is uncertain whether this includes the fleshy, sweet pulp of the fruit pod) are potentially toxic to mammals, including cattle and humans drinking water into which the seeds have fallen

• Twigs
  • brown to gray, very stout and rough, irregular or contorted in its braching pattern, and having huge alternate leaf scars
  • becoming scaly and ridged at a young age, and with relatively few twigs per branch

• Trunk
  • single trunk soon gives rise to several main spreading or ascending large branches
  • ornamental bark is medium to dark gray, with prominent overlapping plates on the branches and trunk

• ID Summary
  • leaves are bipinnately compound and huge, to 2' long and wide, with many leaflets on the pinnae, which attach to the central rachis; when rachis abscission occurs in Winter, it leaves behind a huge leaf scar on the very stout and bold-textured stems
  • bark, both on branches and the trunk, is very coarse, yet is ornamental for this reason, being flared, scaly, ridged, rough, and medium gray
  • green to dull purple fleshy fruit pods, on female trees, weight down the branches in Autumn and early Winter, and contain many seeds, from which a crude, coffee-like extract was once obtained
  • texture is perhaps the boldest of all landscape trees (especially in Winter), as defined by the branching, bark, irregular growth habit in youth, and huge compound leaves in Summer

• Function
  • shade, specimen, or focal point tree

• Texture
  • bold texture in foliage and extremely bold-texture when bare
  • open density when in foliage in youth, but having an average to thick density in foliage with maturity
  • open density when bare, from youth through maturity

• Assets
  • very bold year-round texture (especially in Winter with its coarse branching, platy bark, and relatively few twigs)
  • ornamental bark
  • ornamental fruit pods on female and polygamo-dioecious trees (before abscission)
  • shade is somewhat filtered, due to sparsity of twigs and bipinnately compound foliage
  • very urban tolerant and very tolerant of alkaline (calcareous, chalky, or limestone-based) soils
  • wet or dry site tolerant

• Liabilities
  • irregular branching pattern in youth may be quite awkward and asymmetrical (if left unpruned), and can get out-of-bounds with age if improperly sited in restricted areas (this is not a shade tree for the small urban yard)
  • fruit pod litter from some trees in late Winter

• Habitat
  • zones 3 to 8
  • native to bottomlands of the Eastern, Midwestern, and Central United States

• Alternates
  • large trees having very bold texture (Ailanthus altissima, Carya ovata, Juglans nigra, Quercus macrocarpa, etc.)

• Variants
  • straight species is the only form available, although male selections can occasionally be found (for fruitless character)

• Translation
  • Gymnocladus translates as "naked branch", referring to its deciduous and bold character.
  • dioicus translates as "dioecious", referring to the predominately male and female tree forms (sometimes alternatively spelled dioica).

• Purpose
  • Kentucky Coffeetree is an extremely bold-textured shade tree with ornamental bark.

• Summary
  • Gymnocladus dioicus is a large tree that gives semi-filtered shade, good for its very bold texture, rapid growth, and Winter-persistent large fruit pods on certain trees; often having an irregular shape in youth, but becoming upright oval to spreading rounded and very majestic in appearance with age.