A Quick Guide to Pine Trees

pine tree seedling

If you notice something emerging from your garden soil that resembles an exotic spider or the green tentacles of a misplaced sea creature, do not be alarmed.  You are merely witnessing the germination of a volunteer pine tree seedling.  It probably got there thanks to a bird or a squirrel that swallowed and excreted the seed.  Many seeds will benefit from passing through an animal’s gut since acids secreted in the digestive process perforate the seed coat, allowing the primary root and first shoot to poke through.

I doubt, however, that you will want to allow that pine seedling to grow into a tree.  Pine trees are notoriously huge and are ill-suited to our neighborhoods unless you live on a large estate.   Either they become extremely costly in pruning expense because of their rapid growth rate or they are stricken with bark beetle infestation or a fungus disease that quickly brings about their demise.  And, at least in the case of Italian stone pines, you need to be concerned about them falling over because of their proclivity to lean strongly in one direction.  There is also the matter of pine needle drop which makes it impossible to grow nearly anything — with the exception of certain ferns and Australian rosemary (Westringia fruticosa) — underneath them.
Don’t get me wrong.  Pine trees make a wonderful natural landscape.  If you have ever visited Wrightwood in the San Gabriel Mountains, you might be inspired upon returning home to tear out everything and plant nothing but pine trees around your house.  I once visited Raleigh, North Carolina, and fell in love with the pine forest among which houses in that locale are situated.  It is impossible to match the sweet resinous scent that wafts through a forest of pines.  But short of going whole hog for them, pine trees may be more of a curse than a blessing to the backyard gardener.
Frequently encountered pine tree species in our area, some of them more than a half century old, include Canary Island pine, Italian stone pine, Aleppo and Afghan pine.  Within their first ten years in the ground, each of these species will grow up to twenty feet or more in height and ultimately reach 60 to 100 feet.  Canary Island pine (Pinus canariensis) is the easiest to identify because of its uncompromisingly vertical growth habit and, for this reason, has been used as a parkway or street tree.  Astonishingly, Canary pines are occasionally planted within a few feet of the facade of a multi-story building.  In the course of time, these pines grow up beyond the roof line.  Then the needles accumulate in the rain gutters which must be regularly cleaned out to prevent rain water from flooding the roof.  And if you cut off the top of the tree, all sorts of growth sprouts up along the trunk.  Truly, at this point, the best solution is to remove the tree but, if it comes to that, the building’s tenants may create an uproar demanding that the tree remain in place.
Italian stone pine gives away its identity by its canopy, which is flat along the top.  I saw two of these trees lean precariously for years and predicted that they would topple over, which eventually happened.  One was leaning over the roof of a house and I even notified the homeowner that he should immediately have the tree removed.  Throwing caution to the wind, he persisted in believing that the tree would seemingly remain there forever until one wet and windy night the tree crashed onto his roof.  Luckily, only the roof needed to be replaced and no one was hurt.  Still, these trees are truly magnificent, especially when their trunks are more or less straight and, as an added bonus, they produce edible seeds, also called pine nuts.
Aleppo pine (Pinus halapensis) and Afghan pine (Pinus eldarica), the latter with its unmistakable pyramidal form, are the fastest growing pines for our area.  They are both native to the Middle East and are resistant to drought.  Just make sure you give them well-drained soil and plenty of room in order for them to thrive.
Although pines have their problems, you may still insist on having at least one for sentimental reasons.  Plant selection, often enough, is determined more by the heart than by the head.  For example, if you grew up with a pine tree in your backyard, you may insist on planting a pine when you have a house of your own.  You probably hid behind that tree when you played hide and seek and pine for your children to have a similar experience.  Incidentally, to pine — as to long for something or someone — has nothing to do with the tree but is derived from Latin and Greek words for “penalty,” the idea being that the suffering you feel is a penalty for putting distance between yourself and the object of your desire.

dwarf mugo pines, photo courtesy Handy Andy’s Nursery

Some pine trees are more manageable than others.  Pinon pine (Pinus monophylla) is a slow-growing California native that reaches no more than 30 feet tall at maturity and yields sizable and edible pine nuts, too.  Japanese black pine (Pinus thunbergii) grows to the same height, or even less, in Southern California and has a most distinctive appearance, a natural bonsai look.  Mugo pine (Pinus mugo mugo) is more of a needly ornament than a tree, topping out at a height of eight feet.  Monterey pine (Pinus radiata) is often sold as a living Christmas tree.  This species, when planted in the garden, although extremely fast growing, is not long-lived, succumbing to a multitude of insect pests and diseases when it is no more than ten years old.

The oldest trees in the world are not sequoias but bristlecone pines (Pinus longaeva), growing in the White Mountains above Death Valley.  The oldest coast redwood (Sequoia sempervirens), in northern California, is around 2500 years old, while the oldest giant sequoia (Sequoiadendron giganteum), in central California, is around 3500 years old.  Meanwhile, the White Mountain bristle cone pines are more than 4,000 years of age and are not afraid of heights, existing at altitudes between 8,000 and 12,000 feet.
The bristlecone pine (Pinus aristata) can teach us something about the conditions that favor the longevity of plants. This species survives more wind and cold than any other full-sized tree on earth, yet it outlives them all.
The soil in which bristlecone pines grow is rocky and low in fertility. In its high altitude habitat, the snow may not melt until summer, and the growing season is never longer than four months. Yet somehow these pines endure, probably because the soil they grow in is so poor that no other plants can live in it.  Thus, there is no competition for water and minerals, limited as these resources may be.  Its short growing season may also have something to do with its success since it is not captive to the frenetic and enervating growth rate, as well as the long growing season, of shorter lived species.  Species that have a long growing season allow pests and disease organisms many opportunities for taking up residence within their stems, leaves, or roots.  Ultimately, though, botanists point to the wood of this tree as the key to its longevity.  The wood is extremely dense and resin rich, making it all but impossible for insect pests and pathogenic fungi to gain entrance.
Tip of the Week:  If you have limited garden space or live in an apartment with only a balcony for growing plants, you may wish to focus on containerized specimens.  Bristlecone pine is an excellent candidate for a container on account of its slow growth rate.  Other slow-growing suggestions for containers in full to filtered sun would include Mediterranean fan palm (Chamaerops humilis) and the even slower growing Sago palm (Cycas revoluta) or any of the many related cycad species, all of which have leathery foliage in either sea green or silvery blue.  The pygmy date palm (Phoenix roebelenii) is also a favorite for half-sunny patios and balconies.
Moving from filtered sun into the shade, feathery bamboo palms (Chamaedorea Seifrizii) perform well in containers, as do lady palms (Rhapis excelsa). Nearly all agaves and succulents will live rather carefree lives in containers in sunny exposures, while aloes will hold their own in shadier spots as well.

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