There's no life on Mars, you're thinking, so what's this all about? Well, whether there is or isn't perhaps can't be said for sure, but what is certain is that ancient herbalists like Nicolas Culpepper, selected herbs into categories according to their characteristics. One way of doing this was to group the plants under an astrological planetary ruler, such as Mars the god of war.

This means that there are many flowers, shrubs and trees that have been designated as under the dominion of the Red Planet. Characteristics include red colouring, spines, a hot or biting taste, and an aggressive nature and appearance. Plants of the Spurge family (Euphorbiaceae), or "Tabaibas," as they are known in Spanish, often fit the description well and many species grow on Tenerife. With its reddish desert areas and volcanic mountains, the island appears in many places to actually resemble the planet Mars, so it's not surprising that these plants do so well here.

Whilst some endemic species like the cactus-look-alike Canary Spurge (Euphorbia canariensis), are a common site on the inhospitable wastelands, it also makes a very ornamental addition to the garden. A collection of Euphorbias is both easy to maintain and makes an interesting talking point. These cactus-like plants are suited to growing in hot, dry conditions and are amongst the pioneers that colonize land, which is unsuitable for types that are tender.

The Milk-striped Spurge (Euphorbia lactea) can grow into a small tree, and with its three-edged branches trimmed with short spines, it is another type that resembles a cactus. The white stripe in the middle of the green fleshy stem gives the plant its name and certainly catches the eye.

The Poinsettia (Euphorbia pulcherrima) is one of the best-known species of Euphorbia, which does not have the cactus form. It gets planted in vast numbers in gardens and parks at Xmas, and if it is left to fully establish itself it can become a sizable and impressive bush.

Another type, which is frequently cultivated, is the Crown of Thorns (Euphorbia milii), which has the Martian characteristics of red pseudo-flowers, spiny stems and a white toxic latex, which most plants in this family possess. This species is often to be seen in ornamental borders or can be grown as a potted plant. It is believed by some to have been the shrub from which Christ's crown was made.

Besides, the fascinating Spurge family, there are several other plants and trees in Tenerife that are ruled by Mars. One of these is the Dragon Tree (Dracaena draco), and, in a park in Icod de los Vinos, there is a venerable specimen, which is known as the "Drago Milenario," and is believed to be over a thousand years old. The Dragon Tree was classified under Mars because it has spiky leaves and yields a red sap, which is known as "Dragon's blood." Looking at its strange appearance it is easy to imagine that it comes from another world, and in a way it does, because the Dragon Tree is still in the form it was back in prehistoric times. Dragon Trees can be grown from seed, although these need to be soaked before planting and you can expect a long germination period. The tree is very slow growing so if you can't wait it is perhaps a good idea to get one ready grown from a garden center.

The Pepper Tree (Schinus molle) is another widely cultivated ornamental tree, with reddish spicy berries that have actually been used as a substitute for the condiment. The Chilli Pepper (Capsicum frutescens) not surprisingly is ruled by Mars too, and is easy enough to grow from seed.

Martians used to be represented as little green men, intent on invading Earth, but green fingers can be used for nurturing a range of interesting garden plants, all of which are under the Red Planet's dominion.

Footnote: Gardening the Martian way (first published in Living Tenerife, May 2005, Issue 23)