Being a member of The Hardy Plant Society of Oregon has many perks. One of my favorites is the opportunity to visit other gardeners. It is almost always a pleasant time to visit with other gardeners, and a great time to not only learn about new plants, but also to see new ideas for plant combinations.

There is also the element of seeing a new design feature or how to showcase certain plants.  

On a recent visit to the Portland garden of Gene Rosenboom, a new garden for me to visit, he had a theme that I had not experienced in any other garden. His theme was “Jurassic Plants.” These are plants that would be considered prehistoric, from an age when dinosaurs roamed the earth. Initially Gene’s theme was Japanese maples, then it was conifers, and now today, it is prehistoric plants.

Initially, I was skeptical that there are many plants in this category that we could grow in local gardens, but I was wrong. Walking through this garden and listening to Gene, there are many that thrive here and would also be suitable for many other parts of the United States. The following is a partial listing of some of the prehistoric plants that we can grow here.

Gunnera tinctoria is probably one of the most well-known plants in this category. At some garden centers, it is even designated as “dinosaur food.” Whether dinosaurs actually ate it or not is questionable.

Gunnera fossils have been found from the Cretaceous geological period of about 145 million years ago. It seems to have been native to what is now southern Chile and southwestern Argentina. Planted as an ornamental in the garden, it requires lots of room and lots of water.

It is not unusual for the leaves to reach three to four feet across. In most gardens, they do best with some afternoon shade, because the leaves can get scorched in the hot afternoon sun. The soil must be kept moist.

Plants will usually die to the ground in the winter here in western Oregon, but are rarely killed by the cold. It is classified as an invasive plant in some areas due to its spreading abilities.

Another well-known garden plant is Ginkgo biloba, usually just called Ginkgo. Fossil records show them to be about 290 million years old. At one time they were found all around the world, even in North America.

Ginkgo trees have long been cultivated in China with some trees at temples estimated to be 1,500 years old. Ginkgo are well adapted to our urban environment because they tolerate pollution well. They are often used as street trees and are particularly noted for their outstanding fall color when the leaves turn golden yellow.

There are many cultivars available that are dwarf or semi-dwarf which makes them suitable for smaller gardens. There is a relatively new cultivar, Ginkgo biloba ‘Obelisk’, that is a tight columnar grower, making it ideal for small spaces. Some cultivars offer variegation in the leaves.

Sciadopitys verticillata, Japanese umbrella pine is another well-known landscape plant that is seen in many gardens. Being evergreen, it looks good all year and makes an excellent container plant. It dates to about 200 million years ago. It gets its name from the whorls of umbrella-like needles that grow at the ends of the branches. Give it some shade from afternoon sun to prevent burning. It once thrived in Eurasia and North America, but today it is only found wild in Japan.

While horsetail, (Equisetum hyemale), can be a very invasive weed, but it can also offer a striking statement in the garden under the right conditions, with those conditions being containment! Dating back to about 350 million years ago, horsetail is known for its hollow, jointed stems, with small scale-like leaves arranged in whorls. Fossils indicate that horsetail in prehistoric times, grew to 65 feet tall or more! Today, they are much shorter and spread by underground rhizomes. This makes them difficult to eradicate. In Rozenboom’s garden, he has them planted in about a four-foot-wide bed with a rock wall on one side and a concrete walkway on the other. Gene said that he cuts them to the ground every February and has had his planting for about seven years.

The dawn redwood, Metasequoia glyptostroboides, is another ancient tree that has been found in fossils. It was thought to be extinct until it was discovered in 1941 in China. It is a deciduous, fast-growing conifer and not suited to most urban gardens due to its size of reaching 100 feet or more. Fortunately, there are dwarf cultivars available, one of which I have in my garden called ‘North Light’. With the fern-like foliage that is soft to the touch, it makes an ideal container plant.

The Wollemi pine, Wollemia nobilis, is actually not a true pine, although it is a conifer and an evergreen. It dates to about 200 million years ago. It was thought to be extinct, but was discovered in 1994 by a rock climber in a rainforest gorge in the Wollemi National Park in the Blue Mountains in Australia.

I knew that North Portland gardener Peter Eastman had one growing in his garden and below are his comments.

“This is by far, the rarest plant we grow.  I purchased a small cutting in 2006 from the National Geographic website.  At the time, it was the only way to get one outside of Australia!  The tree was only rediscovered in 1996, so 10 years later, I had my plant!  It arrived in August of 2006, dormant. Australia’s winter of course. 

“I grew it in a pot for the first 15 years as it progressively got taller, and taller, and taller. At the time, no one knew how hardy it would be in the northern hemisphere, so we wintered it first in the basement, then after outgrowing the 7-foot ceilings, into the shelter of a courtyard.  Summers were spent in the garden in the shade of other conifers. 

“Eventually it got to 15 feet tall and the decision was made to permanently plant it in the shade garden.  It loves its present location, in the lee of a large sheltering cedar. We give it regular waterings and some occasional lawn food, but that’s it. 

“You will notice that the middle third of the tree looks brown and burnt. The January 2024 storm did a huge amount of damage.  We weren’t sure it was going to survive.  But survive it has, sending out new lush growth on the top and sending out new trunks from the main trunk.  Eventually it will become a multi-trunk tree, which is common in the wild. 

“What I love about this conifer and why you can tell it is so ancient, is that it lacks the ability to send out side branches.  Each branch sends out one growth spurt from the terminal bud and that’s it.  You can literally count the number of years growth on each branch by counting the growth sections.  This is what gives the Wollemi pine its distinctive skinny appearance.  Conifers later evolved the ability to send out side branches giving them much wider branches which gave the foliage more light and more photosynthesis.  But that evolution came after this plant.”

How does this relate to a retail garden center? Think about how signage has changed in the past few years. New categories have been added that we would not have seen 15-20 years ago. We now routinely see signs for “pollinators,” “native plants,” “Hummingbird attractants” and other examples.

Imagine the attention that a sign reading “Jurassic plants” might create. Garden centers could embellish the whole creative idea by adding photographs of dinosaurs or even toy dinosaurs to captivate gardeners.  

From the August 2025 issue of Digger magazine | Download PDF of article