Swiss stone pine
* Common name: Swiss stone pine
Swiss stone pine is one of the slower-growing needled evergreens.
* Botanical name: Pinus cembra
* What it is: A lot of needled evergreens tend to grow fast and soon overpower the allotted space while “baring out” at the bottom. Swiss stone pine is one of the slower-growing evergreens, staying in a denser, more compact, upright pyramid that eventually tops out at about 30 to 40 feet wide and 15 to 20 feet wide.
The needles are stiff and bluish-green in color. They also hold on the branches for five years and so don’t lead to a lot of yellowing, dropping needles every fall as is the case with eastern white pine.
Native to Europe and Asia, Swiss stone pine produces edible pine nuts, although it takes about 15 for cones to begin growing (plus three years for cones to fully mature).
Pines aren’t the most trouble-free of plants – they can be attacked by sawflies, borers, and bark beetles and can root-rot in too-wet soil – but at least they’re seldom bothered by deer.
* Size: The straight species grows slowly to about 30 to 40 feet tall and 15 to 20 feet wide. Dwarf forms are available, such as the super-slow-growing ‘Nana,’ and narrower varieties are available in ‘Strictus’ and ‘Columnaris.’
* Where to use: The dense, pyramidal habit makes Swiss stone pine a good stand-alone specimen, but it’s also useful as a sunny screen or windbreak when planted 12 to 15 feet apart. Plant in full sun with good drainage. Wet soil is the kiss of death for most pines.
* Care: Improve soil with compost before planting to improve drainage and keep soil consistently damp (but never soggy) for the first full year. Then a good soaking is needed only in an extended hot, dry spell.
An annual spring scattering of an acidifying, granular, organic fertilizer is sometimes helpful but not necessary. A soil test will tell you if you need it.
Pruning is also usually not needed, if you give the tree proper space. Hand-prune or lightly shear overly long branches in June or July, but only if necessary for size control.
* Great partner: Ring with bright gold or red perennials, such as black-eyed susans, gaillardia, coreopsis, mums, and/or daylilies.