bristlecone pines (Pinus aristata)
The oldest living trees on earth are bristlecone pines, some of which are more than 4,000 years old. These pines, which reach 60 feet in height, are native to the White Mountains of California, above Death Valley, where they occur at elevations of 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, at least in the wild. This species survives more wind and cold than any other full-sized tree on earth, yet it outlives them all, including the giant redwood.
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, and there is no competition for water and minerals, limited as these resources may be.
You can’t help wondering what would happen if this tree were planted in Los Angeles. Sunset Western Garden Book says it grows best as a container plant, considering its slow growth rate; it would make a fine family heirloom.
The bristlecones’ chief rivals for longevity, the redwoods, grow fairly well in Los Angeles – as long as they are protected from intense summer heat – and may be an indication of our climate’s suitability to slow-growing, long- lived species. Locally, the largest redwoods I have found, about 80 feet tall, are in the horticulturally friendly confines of Franklin Canyon, between Mulholland Drive and Beverly Hills.
True, Franklin Canyon seems to be a place where just about anything will grow; around the perimeter of the park located at the canyon’s south end, avocados and apples are ripening simultaneously, on their respective trees, at this very moment.
Certainly, not every species of pine should be planted in Los Angeles. Foremost among them is the hybrid Monterey pine (Pinus radiata), which is almost the only pine – or tree, for that matter – grown in local Christmas tree farms. These pines, which also are sold as living Christmas trees, are short-lived when planted from containers, seldom lasting more than five or 10 years in the San Fernando Valley.
There are other pines that, easily grown in our area, get so big that they are not suitable for the back yard. The Italian stone pine (Pinus pinea), with its distinctive flat-topped canopy, and the Afghan pine (Pinus eldarica), probably the fastest-growing pine for dry climates, are magnificent trees if you have a half-acre yard, but otherwise will make you, sooner or later, into a shade gardener.
There are a number of ornamental pines commonly used in Los Angeles gardens. The most popular is probably the Japanese black pine (Pinus thunbergii), since it only grows to about 25 feet in our climate and has a natural bonsai look. Also common are the Canary Island pine (Pinus canariensis), with a strong vertical growth habit, and the pinyon pine (Pinus monophylla), another slow grower to 25 feet that has a silvery symmetrical elegance all its own. Pinus mugo is a dwarf pine that must be protected from the heat in order to prosper.
Pine trees are useful for their needles, bark and seeds. A summer vegetable garden will benefit from a 4-inch layer of pine needles placed around tomato, pepper and eggplants. Needles also may be piled up in a corner of your yard, where they will eventually decompose into a soft, acidic soil amendment. Shredded pine bark – if you can find it – is also highly valued as a mulch, especially where a physical barrier to the germination of weeds is desired.
Avoid planting pine trees in lawns. If the soil does not drain perfectly, the frequent watering that lawns require can lead to fungus disease and insect problems in pines. Also, pine needles can be deleterious to lawn growth.
If you wish to make a gift of bristlecone or pinyon pines, you can find them for sale at the Theodore Payne Foundation in Sun Valley.
Photo credit: ah zut / Foter.com / CC BY-NC-ND
