The Jurassic Garden: Planting in the Footsteps of the Dinosaurs

by Tom Spencer / Soul of the Garden
All gardeners know that a true garden is never
finished. It is always in a state of evolution. Trees grow, shade deepens, some
plants adapt and thrive, while others curl up their toes and die. It is
definitely Darwinian out there. Instead of being distraught by the inevitable
changes that are destined for my back yard, I have decided to get ahead of the
evolutionary curve by planning to devolve. When my trees grow I intend to
convert my sunny perennial beds into a shady Jurassic garden packed with plants
that would make a T-Rex feel right at home.
I have often been accused of being “analog” as opposed to “digital,” a teasing
reminder of my somewhat old-fashioned tastes and modes of operation. I figure
why not go all the way and get downright primeval? After all, the centerpiece of
my back garden is an allee of Bald Cypress trees, primitive yet beautiful plants
whose genealogical roots stretch back to the Jurassic. What better way to
complement a group of trees that provided roughage for the dinosaurs than to
surround them with a mass of other prehistoric leftovers?
I’m not alone when it comes to my dino-fetish. Gardening the Jurassic way has
already taken root here in Austin courtesy of the Hartman Prehistoric Gardens,
located in the very heart of the Zilker Botanical Gardens in Zilker Park.
Popularly known as the dinosaur garden, this acre-and-a-half marvel is the gift
of Claudette and David Hartman, two Austinites who stepped in to help the city
preserve dinosaur tracks that were discovered in the park in 1992. The Hartmans
and a devoted army of volunteers and professionals converted a former quarry
site into a Cretaceous re-creation packed with plants from the dino-era.
Craig Nazor served as a horticultural consultant during the construction and
planting of the Hartman Garden and continues to volunteer a good portion of his
week overseeing its care. He was responsible for choosing much of the plant
material used in the garden and is one of the state’s leading authorities on
cycads. Cycads are a dramatic family of plants that are among the earliest
groups of seed-bearers, so early in fact that they actually pre-date the
dinosaurs! Talking with him has given me cycad fever.
Most Austin gardeners are familiar with Sago Palms, the most commonly available
form of cycad, but Nazor is intent on introducing many other forms to Central
Texas gardens.
“The three closely related cycads—Sago Palm (Cycas revoluta), Prince Sago (Cycas
taitungensis), and Cycas panzhihuaensis (no common name)—are all great plants
and excellent for our area,” says Nazor. “They are all similar in look, but
Cycas taitungensis grows fastest and gets the biggest—it can have an eleven-foot
spread, which is the largest of the bunch. The bluish Cycas panzhihuaensis is
probably my favorite, and very hardy, but it is not as readily available yet and
is rather expensive.”
In the past few years, area nurseries have started to feature a handful of the
more unusual forms of cycad. Of these, Dioon edule is probably the most readily
available species, but there are at least three different forms to choose from.
Nazor has tried them all, “The toughest of the bunch is Dioon edule variety
angustifolia. The bluest one is Dioon edule variety Queretaro. I have a number
of seedlings of Queretaro that are going out in the Hartman Prehistoric Garden
in a few years. I have seen large ones and they look stunning. All can easily
take the worst Austin weather, don’t mind limestone in the least, and are highly
toxic to deer.”
Nazor has planted many other varieties of cycad in the Hartman Prehistoric
Garden, but on a recent visit I was struck by how many common garden favorites
have a similar ancient pedigree. I was most surprised to see birch trees growing
along the paths. River Birch (Betula nigra) is an East Texas native and is one
of my all-time favorite plants. I was pleased to see it being tried in an Austin
setting. (Note: this is most definitely not a plant for folks gardening on
limestone.)
Magnolias were well represented too. This is another very old plant family and
there are many forms that do well in the Austin area. Little Gem Magnolia is a
dwarf form of our standard Southern Magnolia (Magnolia grandiflora) and is well
suited to many garden locations. Another East Texas native that has found a home
where the dinosaurs roamed is the Sweet Bay Magnolia (Magnolia virginiana). This
semi-deciduous tree has blossoms that are much smaller than the Southern
Magnolia, but what they lack in size is more than made up for by their delicious
lemon fragrance. They also feature distinctive lime-green foliage that has a
pale silvery backside. I would love to include a Sweet Bay in my garden and will
monitor performance of the plants in the Hartman garden.
Palms trees of every description also abound in the Hartman garden, so many that
they will require their own article. There are all sorts of exotic varieties,
but the one that I was really excited about is our little native palm, the Sabal
minor, or Dwarf Palmetto. You see, I have already planted a dinosaur garden
under the established trees in our front yard. It doesn’t look Jurassic just yet
(the plants have only been in the ground for a few weeks) but I can’t wait until
our grove of sixteen Palmettos starts to make its presence felt amid the St.
Augustine lawns that line our street. Do you think the neighbors will mind when
I install a statue of Godzilla?