Culture
Best grown in moderately rich, slightly acidic, medium moisture, well-drained soils in full sun to part shade. Best in full sun. Trees tolerate neutral to slightly alkaline soils. Trees may grow poorly in heavy clay soils. Trees are native to mountain slopes and generally have better tolerance for hot and dry conditions than many other trees in this genus. This tree is not reliably winter hardy to USDA Zone 5.
Noteworthy Characteristics
Spanish fir is native to a limited number of dry mountain areas in southern Spain in elevations from 3000’ to 6000’. This is a somewhat narrow, evergreen conifer that matures to broad pyramidal. Trees are slow growing, but eventually rise to 50-75’ tall. Branching typically extends to the ground. Short, rigid, sharp-pointed, linear, dark green leaves (needles to 3/4” long) are arranged radially around the branchlets. Seed cones (to 5” long) emerge greenish pink to purple, maturing to brown. After reaching maturity, the cones disintegrate releasing the seeds. As is distinctive with the firs, the cones appear upright on the branches.
Genus name is an ancient Latin name for a tree described by Pliny around 77 A.D.
Specific epithet of pinsapo may come from Spanish pino meaning pine and sapo meaning fir in reference to the tree being a fir in the pine family.
'Horstmann' is a dwarf selection of Spanish fir with a very slow rate of growth (1-4" per year) that will reach around 2' tall with a 3' spread in 10 years. However, this plant's low, rounded form will not last forever. A central leader is likely to form as this tree ages further, giving it a more pyramidal shape. The leader can be pruned out to help retain a more rounded form. Named for German nurseryman Günter Horstmann, who discovered this plant as a naturally occurring witch's broom deformity on a specimen of Abies pinsapo 'Glauca'. Typically grown as a graft on the rootstock of another species of Abies, such as A. cephalonica or A. frazeri.
Problems
Insect pests for firs include adelgids, bark beetles, spruce budworms, aphids, bagworms and scale. Spider mites may occur in hot conditions. Disease problems include root rots, needle rust and twig blight. Trees are generally intolerant of urban pollution.
Uses
An ideal specimen plant for border fronts and rock gardens.