Above: The Indian Borage is often mistakened as a type of mint.

Unlike various culinary herbs like spring onion and curry leaves, the Indian Borage is rarely sold in supermarkets and wet markets in Singapore. It is more commonly grown as a potted plant and many households grow for its medicinal properties. The plant is used to treat cough and asthma. Several leaves are picked from the plant, washed and then boiled in water. The resulting decoction is taken. The leaves may also be pounded and applied as a poultice on bites from insects. The Indian Borage's flavour is perhaps closest to thyme. In the kitchen, its leaves are used in small quantities and added to mutton and fish curries to mask the strong smell.

Above: Clockwise from top left: thyme (Thymus vulgaris), borage (Borango officinalis), spear mint (Mentha spicata) and oregano (Origanum vulgare). They all look totally different from the Indian Borage, which is also sometimes known by other names like Spanish or Broadleaf thyme and Cuban oregano.

Botanically, the Indian Borage is known as Plectranthus amboinicus and has several rather confusing common names. A rough search on the Internet will yield names like Spanish or Broadleaf thyme and Cuban oregano. In Singapore, people think it is a variety of mint. Those who have seen the so-called true versions of the borage, mint, oregano and thyme will know that the Indian Borage is no way near in terms of appearance. Incidentally, all the true versions of all these herbs belong to same plant family, the Lamiaceae (also known as Labiatae), as the Indian Borage. This herb is so widely cultivated that its origin cannot be ascertained. It may have come from Africa or Indonesia. There is a closely related species, P. barbatus that looks like the Indian Borage. This species can be differentiated from the Indian Borage as it produces fleshy, underground tubers.

At first glance, the Indian Borage looks like an all-green coleus plant, adopting the same shrub-like growth habit. The leaves in both plants are also similarly heart-shaped with scalloped edges. Like the coleus, the entire Indian Borage plant is succulent and does not become really woody. With age, the stems of both plants grow long and leggy, which will eventually trail on the ground and roots will be sent from the stem nodes the moment they touch the soil surface.

Due to its close resemblence to the ornamental coleus plant, it is not surprising to know that the Indian Borage was once classified under the same genus and referred to by the following names - Coleus amboinicus, C. aromaticus, C. carnosa. Note that the coleus has now been reclassified in the genus Solenostemmon.

The only difference between the Indian Borage and the coleus is that the herb is entirely covered with fine hairs and the rather thicker leaves of the former are furry to the touch. When lightly brushed, only the Indian Borage plant will impart a pungent smell. The Chinese name of this plant is known as  (dao shou xiang), which means of "giving fragrance to the hands".

Above: A handsome specimen of variegated Indian Borage, that will add some colour and interest to any herb garden.

Besides the plain green variety that is commonly grown, there is a variegated version of the Indian Borage that is quite attractive. The variegated Indian Borage has leaves that are edged with white. The plant is generally less vigorous than its all green-counterpart. The variegated form makes a decorative potted plant and looks great cascading from a hanging basket. It can also be used as a border plant in herb garden and its variegation is likely to stand out against the mostly green foliage of other herbs.

Culture

Above: The foliage of the Indian Borage turns to a sickly yellow colour if it is grown under full sun conditions.

The Indian Borage is a beginner's herbal plant as it is not easy to kill it. It is a "must-have" plant for any tropical culinary or medicinal herb garden. Although it has been documented in literature that the Indian Borage bears delightful, pinkish-lilac to blue flowers, the plant has not been observed to flower in Singapore. Plants are reported to be able to grow up to a metre in height.

The Indian Borage is able to grow in full sun but under such conditions, its foliage tends to be bleached into a sickly yellow due to water and heat stress. The leaves may also adopt a "cupped" conformation. It is therefore better to grow the Indian Borage in a semi-shaded and moist location to obtain a beautiful jade-green colour in the leaves. If you notice the leaves of your Indian Borage turning a darker shade of green and the leaf-to-leaf distance widening, your plant is telling you that it is not receiving sufficient light. Move it to a brighter spot.

Because of its succulent nature, the Indian Borage is able to tolerate short durations of drought. Don't overwater this plant, as it will rot if it experiences prolonged wet feet. But keep the soil moist at all times. Plant the Indian Borage in a pot of soil that is well drained, with organic matter incorporated into the mix. Feed according to the manufacturer's recommendations, a fertiliser that has a higher content of nitrogen to promote foliage growth. Slow-release fertiliser works well too.

A fast-growing plant, the Indian Borage will benefit from a hair cut if the stems grow too long and straggly. This will help to keep the plant in good shape and encourage bushy growth. One can save these trimmings of leggy, bare stems from a routine pruning regime for propagation.

Above: The Indian Borage can be propagated easily using stem cuttings. Cut back plants often to maintain a bushy growth habit.

The easiest to propagate the Indian Borage is via stem cuttings since seeds are not available. Long stems can be cut into several segments and leaves can be cut away and used in the kitchen. Take note that each stem cutting should contain several nodes. Make sure that the leaves are removed cleanly from the stem for the portion that will be inserted into the soil. Insert the lower end of the stem with at least two nodes into some clean potting mixture and the cutting will root from these nodes. Rooting hormone is usually not required. Tip cuttings will yield "instant" plants. New cuttings are best kept under shade and the substrate should be moist at all times.

Acknowledgement
This article is reprinted with permission from Green Culture (www.greenculturesg.com), an online gardening website set up for plant lovers and by plant lovers.