The Monkey Puzzle Tree: Curious Indeed!

This conifer has such a bizarre appearance it will certainly remind you of the vegetation seen in illustrations of primitive forests labelled “When dinosaurs ruled the earth” and in fact, the monkey puzzle tree (Araucaria araucana) is indeed a survivor of the Mesozoic era. It’s thick triangular needles, tough with a very sharp tip, are even thought to have evolved specifically to discourage herbivorous dinosaurs from munching on them.

You’ll see this living fossil in both private and public gardens, usually in climates where summers are cool and moist and winters are fairly cold, but without deep or lasting frost. It’s not well adapted to hot, dry summer conditions. In the mountainous regions of Chile and Argentina where it grows wild, it certainly experiences snow.

It’s hardy to USDA zone 7 (possibly less with some winter protection) and tolerates temperatures as low as -5?F (-20?C)… but only if the cold is short-lived: it certainly won’t take days on end of subfreezing temperatures. That’s why you’ll often seen it grown in areas that have only brief periods of cold, such as on the west coast of North America, as far north as the Haida Gwaii Islands in British Columbia, and in coastal regions of Europe as far north as Scandinavia (on the island of Smøla, which despite its location at the 63rd parallel north, is bathed by the warm waters of the Gulf Stream). It rarely does well far inland in either Europe or North America other than near large bodies of water, as continental climates tend to experience prolonged cold. It also grows successfully in New Zealand and Australia.

Almost Reptilian

It’s the curious appearance of the monkey puzzle that grabs our attention: it almost looks like something from another planet! The branches grow in whorls and are few and well-spaced, giving it a sparse appearance. Yet they appear very thick, since they are heavily covered with dark green “scales” (very broad needles), giving the tree a reptilian look, like a dinosaur tail. Over time, the lower branches drop off, making mature specimens look like a giant mushroom.

In its native land, it can live up to 2000 years and reach up to 130 feet (40 m). I know of none of that size in cultivation – so far, at least – but a few do reach 75 feet (23 m).

It Never Met a Monkey

As for its common name, monkey puzzle, it comes from the comment of British barrister Charles Austin in the mid 19th century. Upon seeing a monkey puzzle tree, only recently introduced to gardens at that time, he remarked “It would puzzle a monkey to climb that.” It quickly became known as the monkey puzzler, then finally the monkey puzzle tree or just monkey puzzle.

In fact though, there are no monkeys in the part of South America where the tree grows naturally. Even so, I’ve seen squirrel monkeys carry out some pretty incredible aerial acrobats and I’ll bet a truly nimble one could climb a monkey puzzle… if it had a good reason for doing so!

Bizarre… and Useful

The monkey puzzle produces at large edible pinion (nut) and it fact both parts of its botanical name, Araucaria araucana, refer indirectly to that, since it is named for the Araucanians, a Chilean people for whom monkey puzzle pinions were a staple food. There was even a project to plant monkey puzzle orchards in Scotland, where the tree grows well, but the fact that you have to wait 40 years before the trees begin to really produce a good quantity of pinions finally discouraged the promoters from going ahead with their idea.

Mature female specimens (the species is usually dioecious, with separate male and female plants) produce a huge prickly cone up to 8 inches (20 cm) in diameter. But don’t worry that it will drop on your head as you pass underneath: instead it disintegrates when it matures, dropping the pinions to the ground. In the wild, birds and rodents are responsible for dispersing the seeds, thus ensuring the survival of the species.

And it’s not just the pinions that are useful: monkey puzzle wood was long used as a fuel and building material in Chile, but the species has been protected there since 1979, since so many of monkey puzzle forests were cleared for agriculture in the past that it is now threatened in the wild… and Chile is taking protecting this tree very seriously.

Growing Your Own Monkey Puzzle Where It’s Not Hardy

I live in an insanely cold region (USDA zone 3, AgCan zone 4) to be trying to grow monkey puzzles, but I must confess that I did. I ordered seeds from Chiltern Seeds in Great Britain (they still offer them, but I’m not sure they’re allowed to export them at this time without a CITES permit) and sprouted them indoors under lights.

They’re short-lived seeds, sent directly from cold storage, and have to be sown immediately. They’re quite large: you just insert them into a moderately moist potting mix and wait. Mine took about 2 months to germinate.

After 3 years, I tried planting two outdoors, figuring they might do all right under snow cover. One simply croaked. The other survived the first winter, but died about two months later. I figure this was probably a base of plant suicide: I don’t think it ever wanted to go through another one of my winters again!

I lost the 3 others over time for various unrelated reasons (mealybugs got one, another dried out while I was out of town and the final one died in winter of what I suspect was rot), but still they seemed to reasonably well as houseplants. They did like spending their summers outside, though. And I kept one 8 years with no special care, which is longer than most houseplants last.

Even so, I almost count myself lucky that I lost them. Had they really taken off, where would I have put them? After all, they’re insanely prickly and they become huge. I can’t imagine myself lugging a huge potted monkey puzzle outdoors each summer and indoors each winter without a suit of body armor!

I grow another araucaria indoors: the Norfolk Island pine (A. heterophylla) and it is smaller (at least in its youth), more densely branched and not at all prickly. Plus is it more tropical, better able to tolerate indoor temperatures. It definitely makes a better houseplant, plus it has the advantage of being widely available (it is sold in garden centers everywhere).

Growing Monkey Puzzle Outdoors in a Moderate Climate

For those of you in zones 7 to 11 under fairly humid conditions, you could definitely try this plant outdoors. In Europe, it’s relatively easy to find in nurseries, at least in those coastal regions where it grows well. In North America, it is rarely available in the center or east of the continent, but appears fairly readily in garden centres on the West Coast. If you can’t find it locally, try Forestfarm in the US, Fraser’s Thimble Farms in Canada or Tree Shop in Europe.

It adapts to almost any well-drained but moist soil and can grow both in partial shade and full sun.

The monkey puzzle: a curious plant indeed! If you have the right growing conditions, just plant it and watch it do its reptilian thing!