- Why the ancient cycads are popular and trendy again.

Inevitably, what is old becomes new again when it comes to trends and fashions, even in the gardening and landscaping sphere.

While cycads no longer dominate our planet’s flora, their direct descendants are enjoying a 21st century revival in subtropical and tropical gardens up here. This is because, as well as being lush architectural goodlookers, they’re low maintenance and environmentally sustainable. Most cycads originate from arid hotspots in Mexico, Australia, South Africa and China where they have evolved to cope with dry conditions so, once they’re established, they thrive without water even in our increasingly hot and dry summers.

Cycads are a big, complicated family of more than 300 species, so identification can be tricky with just subtle differences in leaf shape and cone structure differentiating them, but there are three main families: Cycadaceae, Zamiaceae and Strangeriaceae. We usually see only species from the first two families in gardens here.

Cycas revoluta is the most popular of these. It is from the Cycadaceae family and its common name, sago palm, is misleading on two counts – it looks like a palm but is in fact a cycad, and because sago generally refers to an edible starch extracted from the similar-looking true sago palm, Metroxylon sagu.

Cycas revoluta plants begin life as a single stiff feather-like shoot from either a seed or a pup, slowly maturing into a central ball base supporting layered near-horizontal leaf fronds. Eventually, a new whirl of leaves bursts vertically (up to almost 1m on mature plants) from the centre then unfurls, often to double the plant’s size.

Even more spectacular are their cones. When cycads are mature enough to start reproducing, they bear male and female cones on separate plants (they’re dioecious), and unlike birds where it’s often the male that makes the most show, it’s the female Cycas revoluta cone that turns eyes. These spherical cones can be bigger than a basketball and their initial surface of scales morphs into a filigree pattern of protective sheaths enshrouding the cone. As the cone matures, it opens to reveal bright red teardrop seeds supported in a nest of remaining sheaths, and if these are pollinated, they drop and germinate either on the trunk of, or close to, the mother plant. The male cone is taller and phallic-shaped but less showy.

I’ve noticed that fertile Cycas revoluta seeds sometimes root as a separate plant close to their mother and can be transplanted, but sometimes they are more like pups literally attached to and growing from the mother plant’s central ball. I’ve sawn these off and transplanted them with just their own ball (no roots) for sustenance, and after going backwards for a few weeks, most sprout into new life.

One of the reasons Cycas revoluta are popular is because they are also one of the hardiest cycads. Originating from Japan, they will tolerate temperatures of about -5C once mature, will grow in full sun or semi-shade, and will tolerate dry and coastal conditions. They grow slowly but their wheel of foliage can extend to over 2m wide, and some of the plants here that are about 30 years old are sitting on squat trunks just under 1m high, making them great landscape plants where you want to enjoy strong architectural form in tough conditions at an accessible height.

Macrozamias (from the Zamiaceae family) are the other prevalent cycads up here. A lot of these are native to Australia where some of the 40 species grow wild in dramatic stands under eucalyptus, and they look similar to sago palms but are taller with more upright, softer foliage.

There seems to be two Macrozamias that are popular in mature gardens here, one of which is the graceful Macrozamia communis. Several specimens of these are a standout in a friend’s garden with arching feather fronds that are nearly 2m long. The plants eventually create football-sized scaled cones at the base. These look like giant pineapples and when they mature the scales break away in segments.

Three macrozamias in my own and other gardens up here produce almost identical pineapple-shaped cones but their foliage is coarser and stiffer, and their identity still a mystery. I welcome suggestions.

Other Zamiaceae stunners that I’ve seen growing happily outside here are Dioons with their fine blue-grey foliage, Encephalartos with leathery and often spiky foliage, and the flat-leafed cardboard palm (Zamia furfuracea), but all of these are in warm, sheltered spots protected from frost.

Nearly all cycads need free-draining soil. They are stunning features in pots both inside and out, and are fairly pest and disease free if they have good light and free-draining mix.

Cycads used to be hard to source but as these time travellers come into maturity in New Zealand, there is now more local propagation material around. However, you have to be patient. Seed is slow to germinate and it takes several years before cycads are a plant of any size.

These living fossils with such a long lineage are clearly not in any hurry.

Cycads were the dominant plants when dinosaurs roamed the globe. And they look like it too. There is something primeval about this dramatic group of plants.