Cycads are a group of plants that are mostly ornamental and have been wiped out from the wild. It is because of their use for decorative purposes in modern buildings and corporate offices. We have deprived them of their natural house viz. wilderness and domesticated them. We have done the same for wheat, which was nothing but wild grass, and the repeated cultivation of a few species of the same has resulted in a monoculture that is dangerous for biodiversity.
You may have come across a dinosaur picture with a palm-like tree by its side. You may also have observed such plants growing in the vicinity of where you live. These plants are cycads and they date back to the age of dinosaurs. Cycads and the dinosaurs both dominated the Earth at the same time, but, only cycads have managed to survive to date. They have not evolved much but have been better adapted to Earth, thanks to their coralloid roots that perform amazing functions.
Some people think of cycads as plants closely related to ferns and palms because of their superficial and morphological resemblance to these groups. But, on the other hand, they are distinct from both.
Ferns are vascular plants that do not contain seeds or flowers. On the contrary, palms are angiosperms or flowering plants and contain seeds and flowers both. On the contrary, cycads fall somewhere between the two and bear seeds, but not flowers.
Naturally, cycads are grouped into gymnosperms or seed-bearing plants. But some biologists have argued that they are distinct from gymnosperms. Nevertheless, cycads bear seeds and are gymnosperms or closely related to them.
Nowadays, cycads are known as the relics of the old plants that enjoyed their domination of the planet Earth somewhere 150 million years ago, in the Mesozoic era. Cycads are often called living fossils because they have survived eons and because of their matchless longevity. Cycads bear motile sperms that are reminiscent of the movement of plants from water to land.
We can find them in the tropical, subtropical, and temperate regions of both the north and south hemispheres. Cycads exist in substantial numbers in the continents of America, South America, Africa, and Australia. Cycads are also very common in Central America and the Caribbean Islands. The most wide-spread genus is the Cycasoccurring in areas as wide apart as Japan and some coastal areas of Africa.
Though cycads are woody plants that have roots, stems, leaves, and reproductive structures known as cones, cycads are devoid of flowers and fruits. However, they produce seeds that are sufficient for propagation.
Speaking of the roots, there are thickened and somewhat fleshy roots also known as tuberous roots. Cycads are the main roots and have a contractile function (they can pull the plant into the ground a little bit). Then there are branched, specialized, and upward-facing roots that are called coralloid roots (because they resemble corals). These roots serve to fix the nitrogen because they contain blue-green algae. These specialized roots are generic to cycads and are found in all species.
Coralloid roots have a rich diversity of microbes inside them. These microbes produce compounds that help them communicate among themselves as well as with the plant. They transport nutrients and perform other functions that are a mystery to date.
The stem may be subterranean or above ground, depending upon the soil texture. In stony, shallow soils it may emerge from the ground and become a trunk.
The leaves are pinnate (divided) and may give a palm-like appearance. Some species form leaves that resemble maidenhair fern leaves, while in some species, the leaves are divided twice and are called bipinnate.
Cycads reproduce sexually and are monocious, meaning that there are male plants and female plants. Upon maturity, both male and female plants form cones that differ in shape, size, and to a lesser degree in color. Cycads male and female cones form sporophylls inside them, which are responsible for the production of male and female gametes. Pollens are carried by the wind, or by small bees and weevils that are attracted to scent and heat, to ovules, which, upon fertilization, form seeds. The seeds are large and contain an outer thick covering called sarcotesta.
The seeds also have a fleshy outer layer that is relished by animals that are vectors for their dispersal into new areas. Cycads mostly grow in open lands and it is common to see them germinate following fires.
How to grow cycads?
Since cycads are robust and have matchless longevity, they are relatively easy to grow indoors as well as in your garden. All they need is soil with good drainage. The best way to grow cycads is by growing them in terra cotta pots with potting soil, compost, and cactus mix. They like to remain root-bound so do not try to re-pot them so often.
When planting from a container, make sure you extract a young plant. It is because they do not want their roots to be uncovered before they form a trunk. It is always best to transplant the plants in summer when the temperature is increasing. Always remember that cycads need well-drained soil.
Cycads need little water but when growing indoors, you have to water them properly. In summer, you have to water them twice a week or they will wilt. On regular days, you only need to water them occasionally. The soil needs to be kept moist but not saturated with water or cycad roots will rot.
Avoid putting them near a direct heat source, instead, you should put them under natural sunlight. If it is growing outside, it will need direct sunlight and a temperature of about 20 C.
Speaking of fertilizers, cycads will need to be fertilized four times a year if you want to see them grow profusely and in an abundant manner. A typical fertilizer for palms containing nitrogen, phosphorus, potassium, and magnesium with an additional amendment of micronutrients is more than sufficient for your plants.