Pinus mugo 'Jakobsen' is a clumpy, somewhat contorted selection of mugo pine. Bud clusters are often seen arranged in groups of three along a single plane which will, at times, allow a plant to produce fasciated branches. Needles are very dark green and are clumped tighter than those seen on the species. The bud structure and dark needles suggest to some that 'Jakobsen' may actually be a hybrid of P. mugo and P. nigra. Typical rate of growth in most areas is 2 to 4 inches (5 - 10 cm) a year, producing a large bushy pine 40 inches (100 cm) tall and usually somewhat wider after 10 years in the landscape.
Arne Vagn Jakobsen of Denmark is credited with the origin of this cultivar sometime in the late 1980s. It should be noted that the first official publication of this plant name was in the World Checklist of Conifers by Humphrey Welch and Gordon Haddow ©1993. They listed it under the name, 'Jacobsen' which is clearly a misspelling of the originator's name. This is also how the plant is listed in the RHS Horticultural Database. Other common misspellings include 'Jakobson' and 'Jacobson.'