At first glance, stone pines may not look like edible plants, but these tall conifers are the source of the pine nut. Pine nuts, the small, naked seeds that fall from pine cones, are one of the ingredients of pesto (blended with basil, garlic, oil and Parmesan cheese). Pine nuts are known as pignoli or pinoli in Italian. These trees grow naturally through southern Europe and Turkey, developing a distinctive flat-topped shape that’s very diﬀerent from the typical pyramidal or Christmas-tree shape of most pines.The trunk is often bare of leaves, with red-grey bark, and it tends to develop a distinctive lean as the tree grows. The cones that contain the edible nuts are rounded and shiny brown.
The name “pine” is often used to generally describe any evergreen conifer, but true pine trees have long leaves – termed “needles” – arranged in bundles.
In the case of the mature stone pine, these bundles are formed with a pair of needles that can be 10–20cm long. Juvenile trees don’t have paired needles.
Stone pine Facts
Common names: Stone pine, umbrella pine
Botanical name: Pinus pinea
Family: Pinaceae (pine family)
Aspect & soil: Full sun to part shade, well-drained soil
Best climate: Cool, Mediterranean, temperate
Habit: Evergreen tree
Propagation: Seed, potted plant
DID YOU KNOW?
Stone pines were planted along ancient roads. They can still be seen on the streets of Rome including the famed Via Appia.
HOW TO GROW AND HARVEST
As stone pines are Mediterranean in origin, climates with cool to cold winters and warm summers suit them. They don’t grow well in hot and humid areas.
The trees take around 10 years to mature and produce nuts, so it’s perhaps useful to think of them as attractive ornamental trees that will eventually become food plants. A mature pine can top 20m in height and develops a canopy that spreads 6–8m across, like a living umbrella. This mature shape leads to its other common name of “umbrella pine”.
Pines are ancient trees that don’t have true flowers but instead produce separate male and female strobili. Cones form when the female flowers are fertilized by pollen blown from male strobili, and protect the naked seed.Harvest is a matter of waiting for the mature cones to fall then picking them up and emptying out the seed. It’s something humans and animals – particularly birds – have been doing for thousands of years.That’s the good news. The bad news is that it can take up to three years for cones to mature. Often the cones need to be kept in a warm spot until they release their seed.
The seed is encased in a brown shell, which has to be removed before the pale, shiny, edible nut is revealed. Stone pines are naturalized in parts of Australia and have also been planted in parks. If you can find a mature pine, stake it out for the future and, as the cones mature, get ready to scavenge the prized pine nuts.