Daily Archives: December 16, 2011

Have a Great Weekend

Introducing Araucaria heterophylla

Norfolk Island pine with dinosaurs

It shouldn’t be any surprise by now that I love oddball plants, and my favorite oddballs are the ones that hide in plain sight. Every Christmas season, garden centers and grocery stores are full of live trees for folks who don’t have the room for a full-sized Christmas tree, or who want a live tree to enjoy after the season, or who just want something different with a touch of green in an otherwise dreary winter. You can find actual fir saplings available for sale, or rosemary pots shaped to look like a tree. The best one, though, is sold as the “Norfolk Island Pine”. This bushy little tree, Araucaria heterophylla, isn’t just a great live tree that looks good throughout the year, and that does remarkably well indoors. It’s also the most accessible link to a group of plants that were the dominant trees for a fair portion of the reign of the dinosaurs.

Norfolk Island pine

A. heterophylla is a member of the Araucariaceae, a group of now widely separated species of conifer that include the kauris (including the giant kauris of New Zealand), the monkey puzzle tree of Argentina and New Caledonia, and the Wollemi pine of Australia. Although increasingly endangered on Norfolk Island itself, these trees acclimate well, and are now found throughout the world. In that sense, they’re only returning to their former range, as the Araucariaceae used to be the dominant tree form through most of the Southern Hemisphere back when the southern continents were jammed together as Gondwana. Norfolk Island pines have a rather prehistoric appearance, which isn’t surprising since the group has been hanging around for nearly 200 million years.

As such, A. heterophylla is probably the only araucarid most folks in Texas will ever see: monkey puzzle trees need cool temperatures and high humidity to grow (which is why they do rather well in Portland), and Wollemi pine distribution to the US stopped shortly after they started. The Norfolk Island pine isn’t exactly suited for outside life in North Texas, either, as it does best with humidity of at least 50 percent. Seedlings and saplings also don’t do well with North Texas-level summer sun, although they thrive when given a good dose of morning sun and good indirect light for the rest of the day. The biggest issue with raising them involves moisture, because seedlings and saplings have a very particular Goldilocks zone of soil moisture. As most gardeners already know, the symptoms of too much water and too little are almost identical, and a tree in a completely dried-out soil mix is indistinguishable from one with terminal root rot from sitting in mud. Norfolk Island pines tend to do well in a very well-draining mix, but also one that stays moist. After the tree is at least a meter tall, that’s much less of a concern. (If a few branches go dull and dry out, this isn’t as much of a concern. If all of the tree goes dull green and brown, though, it very rarely recovers.)

Oh, and that’s another bit of fun concerning the species. Several araucarids qualify as some of the largest trees on the planet today, including the magnificent Tane Mahuta kauri of New Zealand. Norfolk Island pines don’t get quite that big, but given the right conditions, they can reach heights of 200 feet (60.96 meters). As stated before, they won’t reach those heights in North Texas, but they have no problems with reaching sizes too large for a windowsill if regularly fertilized. Kept under lower-light conditions and fertilized twice per year, though, they get wonderfully bushy, adding to the prehistoric effect.

And that’s where I’m going with this. Considering the amount of interest in prehistoric miniature gardens, you can’t get much more authentic than A. heterophylla for Jurassic and Cretaceous-themed miniature gardens. Keep them under the same light, heat, and humidity as most ferns, and you have a very resilient and attractive addition to the floral palette. Even in a standard pot, A. heterophylla is a preferable option to firs and other conifers for indoor plants. And if you live in a place where one would do well outdoors…don’t tell me about it, unless you want to hear the sound of my teeth grinding in impotent jealousy.