Category Archives: Herbs

All about herbs, medicinal and culinary…

Persicaria capitata – A Groundcover for Medicinal Gardens

Persicaria capitata is a medicinal plant known via a range of common names which include Pink Knotweed, Japanese Knotweed, Himalayan Smartweed and Pink Bubble Persicaria. A member of the Polygonaceae family, this plant used to be known botanically as Polygonum capitatum but now has been reclassified into a new genus, Persicaria.

A native of Asia, this plant has naturalised in various parts of the world and has become an invasive weed in areas where the climate permits. It is an herbaceous plant that adopts a prostrate growth habit, meaning it creeps near the surface of the plant. Owing to this growth habit, Persicaria capitata is often grown as a groundcover plant.

A candidate for medicinal gardens, it is a highly ornamental plant suited for planting in the foreground in a landscape. For example, it can cleverly be grown between some rocks. The leaves of Persicaria capitata are green in colour and the chevron that adorns each leaf becomes more obvious under direct sunlight. The reddish stems contrast against strongly the foliage. Flowers of this plant are produced freely in the form of small pink globes that are held well above the foliage. This plant emits a strong odour when parts of it are crushed.

Persicaria capitata is a perennial plant in Singapore which prefers to be grown under direct sunlight and a moist, well-draining location. It seems to be able to grow in poor, clayey soils and can be drought-tolerant when established. Under optimal growing conditions, it is able to form a dense mat of foliage that hugs the ground. It is relatively pest- and disease-free under local conditions and can be easy to propagate it via stem-cuttings. Note that it is important to plant Persicaria capitata in a weed-free area as it has been noted that grassy weeds can still grow through a dense mat of this plant and eradication of these unsightly weeds can be very difficult to perform.

Persicaria capitata is used in Traditional Chinese Medicine where its aerial parts are used to brew a tea which is consumed for the treatment of a range of urological disorders, such as kidney stones and urinary tract infections. An in-vitro study reported that traditional use of this plant for the treatment of urinary tract infections can be attributed to the presence of anti-bacterial and anti-inflammatory agents found in the plant. Persicaria capitata has also been found to contain antioxidants.

Passiflora foetida – A Weed with many Roles & Uses

Passiflora foetida is a member of the Passion Fruit family, Passifloraceae. It could have been a native of South America but has since naturalized in most tropical countries, including Singapore. Unlike its relatives, namely, the Giant Granadilla (Passiflora quadrangularis) and the Common Passion Fruit (Passiflora edulis), Passiflora foetida occurs mainly as a weed and it is getting uncommon nowadays as Singapore continues to urbanise. A number of varieties of this plant are known to exist.

Its common names include the Stinking Passion Vine or Wild Water Lemon. Its species name ‘foetida’ has the meaning of “stinking” in Latin which refers to the strong odour that is emitted by damaged foliage. Note that the stems and leaves of this vine are toxic and suspected to have caused poisoning in livestock. Interestingly, the young shoot tips and leaves are also valuable, wild-gathered vegetables in several South East Asian countries where they are thoroughly cooked by boiling first and then consumed in a soup. Leaves have medicinal properties where they are used to treat neurasthenia, insomnia, early menstruation, edema, itching and coughs.

The plant itself, is a vine, like other Passiflora species. The stems of this plant are thin and wiry and covered with numerous sticky hairs. They are herbaceous when young and gradually turn woody with age. Its leaves are three- to five-lobed and hairy to touch too. The flowers of this plant are quite attractive but small in size, about 5 cm in diameter. Flowers are usually white in colour with a purplish center.

The fruits of this species are quite interesting as they are encased with leafy sepals that are finely dissected. Each fruit is about 2 to 3 cm in diameter and they turn from green to orange when ripe. There are varieties which produce fruits that turn red when ripe. The fruits do not split open when ripe. Note that the young fruit is cyanogenic and hence poisonous. They are only edible when ripe and children in rural villages in Singapore decades ago would be able to recall the fun of popping the yellow/orange ripe fruits into their mouths as they play along in the kampong. Each fruit has numerous black seeds embedded in the whitish, sweet pulp where seeds dispersed by birds.

Passiflora foetida is considered as a protocarnivorous plant. When the vine flowers, the leafy sepals that encase the flower are reported to produce sticky, dew-like secretions at the tip ends and these may help the plant to trap insects. There is insufficient evidence to show whether or not, the plant gains any form of nourishment from trapped prey.

This Passiflora species mainly occurs as a weed, sometimes invasive, in wet areas although it can tolerate drought when established. It is common in plantations, rough pastures, roadsides and wasteland. It is a ‘useful’ weed which is sometimes used as a soil cover in plantations to control lalang (Imperata cylindrica) and soil erosion.

It also plays an important ecological role. The young leaves and shoots of Passiflora foetida are consumed by caterpillars of the Leopard Lacewing (Cethosia cyane) and Tawny Coaster (Acraea terpsicore) found locally in Singapore.

Pereskia bleo – A Leafy Cactus

Pereskia bleo is a common medicinal plant grown in Singapore. Locally known as the ‘Seven Star Needle’ (qi xing zhen), this plant is a member of the cactus family. The genus was named in honour of Nicolas Fabre de Peiresc, a French botanist of the 16th century.

However, this cactus is a leafy cactus that is not a desert-adapted plant like many other leafless cacti we are familiar with – it grows in the shady and moist forests of Central America. This probably explains why specimens grown in hot and sunny spots often become yellow and stunted. Desert cacti have lost all their leaves to avoid excessive loss of water via transpiration.

It may seem strange at first that it can be a cactus with leaves. In fact, this genus of plants is determined one of the two genera from which all other cacti evolved. If one look closely at the stem of the Pereskia, a tell-tale feature that it is a cactus is evident via its cluster of spines grow from specialized structures called areoles which is a feature that all true cactus species have.

Some English common names of Pereskia bleo include Leaf Cactus, Rose Cactus and Wax Rose. These common names somewhat describe some characteristics of this plant. Pereskia bleo is a true cactus and it is one with leaves unlike many others that are commonly grown as houseplants. The latter two common names very well describe its rather large and highly ornamental flowers with multiple thick orange petals that are arranged in almost the same manner as seen in roses. After flowering, plants produce interesting, funnel-looking fruits which ripen into a bright orange colour.

Pereskia bleo can grow into a small, woody but prickly tree of about 2 m in height. It can take relatively hard pruning which can be employed to help keep it small and manageable. Its prickly nature can be exploited for using it to make a living fence – individual plants can be planted at regular intervals to form a prickly screen to deter intruders. Plants are propagated most easily via stem-cuttings. It is best grown in well-draining soil rich in organic matter and kept moist at all times. As mentioned above, unlike other leafless cacti species, this plant is not exactly a succulent and hence not drought-tolerant.

The leaves of this plant are eaten raw by locals here with the belief that it can prevent or cure one of cancer. Leaves are relatively blant to taste. Solid scientific evidence to support this belief is still not available as limited scientific studies have been done to date and all are still confined to the petri-dish. Reference of these studies are given below:

  • Tan ML, Sulaiman SF, Najimuddin N, Samian MR and Muhammad TS. 2005. Methanolic extract of Pereskia bleo (Kunth) DC. (Cactaceae) induces apoptosis in breast carcinoma, T47-D cell line. J  Ethnopharmacol, 96(1-2):287-94.
  • Er HM, Cheng EH and Radhakrishnan AK. 2007. Anti-proliferative and mutagenic activities of aqueous and methanol extracts of leaves from Pereskia bleo (Kunth) DC (Cactaceae). J Ethnopharmacol, 113(3):448-56.
  • Malek SN, Shin SK, Wahab NA and Yaacob H. 2009. Cytotoxic components of Pereskia bleo (Kunth) DC. (Cactaceae) leaves. Molecules, 14(5):1713-24.

Introducing the Green Pepper Basil

The Green Pepper Basil is a rare and unique basil species that does not look, smell or taste like a typical basil that we grow in the kitchen garden. It is botanically known as Ocimum selloi, where the species epithet is named for Friedrich Sellow (var. Sello) (1789-1831), a German botanist and naturalist, one of the earliest scientific explorers of the Brazilian flora. This basil species was reported to be first collected near Chiapas in Mexico, by botanist Dennis E. Breedlove.

The serrated leaves of the Green Pepper Basil are glossy, deep forest green and leathery. I came across a website that this plant looks like a pepper plant (Capsicum species) and I am in agreement with it. This plant produces numerous small violet flowers on arching spikes. Unlike most other commonly encountered basils, flowering does not adversely affect the much leaf production. It noticed it is a highly ornamental, fuss-free and rather pest- and disease-resistant basil species compared to the culinary ones – it is a potential candidate for testing in companion planting to ward off undesirable pests in a herb and spice garden.

The leaves of this basil have a milder, more complex flavor than most culinary basils and are described to be like a combination of green pepper and basil. It is said to be able to hold these flavors through cooking, freezing and microwaving. This contrasts against bell pepper and basil which do not normally withstand such harsh processes.

According to sources on the internet, the leaves of the Green Pepper Basil are said to be good to flavour corn soup, cabbage, scrambled eggs, and mixed with cream cheese to spread on crackers. One source cited its use in salads. Like many herb plants, Green Pepper Basil also has medicinal uses – its leaves been traditionally used to treat stomachaches and infuse in baths for fever.

Like most other basils, the Green Pepper Basil should be grown in a well-draining position with fertile soil that is kept moist at all times. It can be grown in a sunny spot like other Ocimum species and cultivars but interestingly, an internet source mentioned that this particular basil species should be grown in semi-shade as leaves will become tough and inedible if grown under full sun!

Introducing the ‘Cincau Plant’ – Mesona

Most Singaporeans would be familiar with the grass jelly that is served as a chilled dessert, served commonly either in strips soaked in soybean milk or in cube form bathed in sugar syrup. In Chinese, this foodstuff is referred to as ‘xiancao’ (仙草, literal translation means ‘fairy herb’) and ‘cincao’ in Malay.

Whilst most of us are familiar with the foodstuff itself, not many would be familiar with the plant. The plant that produces the black grass jelly in part of the world is a species from the genus Mesona and is a member of the mint family (Lamiaceae). Two species of Mesona, namely, M. chinensis and M. parviflora, have been reported to be used to make grass jelly. From what I have researched, M. chinensis appears to be the one used in southeast China and Taiwan while M. parviflora seems to be more popular in Indonesia. Chinese refer to M. chinensis as ‘凉粉草’ (liang fen cao).

Plant Resources of South East Asia states that the two species may be conspecific, meaning they may be similar. A check with Flora of China database yields slightly differing foliage characteristics given below. It is well known in the Plant Kingdom that a single species of plants with a widespread distribution can be variable in appearance. From the description below, I believe the one I showed in this post is M. chinensis.

Mesona chinensis (syn. M. procumbens) - Leaves narrowly or broadly ovate to subcircular, apex acute to obtuse, base cuneate to sometimes rounded . (Cruneate – a leaf with a wedge-shaped base with edges that form an angle less than 90 degrees, but greater than 45 degrees.)

Mesona parviflora (syn. M. palustris) - Leaves narrowly elliptic or ovate-lanceolate, apex short acuminate, base attenuate (Attenuate – a leaf with a tapering base with concave edges that form an angle less than 45 degrees.)

Leaf characteristics reference - http://www.northernontarioflora.ca/leaf_bases.cfm

The aerial parts of Mesona are picked and dried. During the drying process, leaves are allowed to oxidise where they also turn dark. To make the jelly, leaves are boiled in water with the addition of an alkaline substance such as potassium carbonate (ash from burned rice culms is also said to be used). The resultant solution is filtered through cloth and then cooled where it then solidifies to give the familiar gelatinous solid. Leaves of Mesona are believed to have ‘cooling’ properties in Chinese medicine .

In the garden, both species of Mesona make great groundcover plants for a herbal garden. Their sprawling and dense growing habit ensures any bare patches of ground are covered green and prevents soil eroson. Their leaf surfaces are shiny and the serrated foliage margins add interesting texture to the landscape. These plants produce numerous small flowers on erect spikes which are coloured blue – a rare floral colour in the tropics.

Jekka’s Herb Cookbook

Jekka McVicar, the Herb Queen, as she is widely known, has published another book on herbs. This time, it is a cook book, in contrast to her earlier ones which focussed on how to grow these aromatic plants. For Singaporeans, this book is about how to use so-called ‘Western herbs’ in the kitchen and you may have expected, Jamie Oliver, has a part in this book where he penned the foreword.

In this book, the reader will be able to find uses for 50 herbs. The common ones like basil, bay, chives, dill, lemon balm, marjoram, mint, oregano, parsley, rosemary, sage, tarragon and thyme can be found, as well as, a selected few Asian ones like celery leaf, coriander, curry leaf, lemon grass and shiso.

Unlike many cookbooks, the reader won’t be able to find colourful pictures of the final dish that are often included to inspire the one to start cooking. One will instead find colour illustrations of the herbs featured which were the work of Jekka”s daughter, Hannah.

For each herb, Jekka starts off with a short personal anecdote, followed by a description and brief growing tips. That then leads to its history in cooking, harvesting notes, medicinal properties and the various cultivars that are available to the cook or gardener. A handful of recipes are presented in the pages that followed. What I particularly find useful about this book is that Jekka gave tips on how to use excess herbs that may be produced by a bumper harvest. She also provided warnings whenever applicable, such as the risk of using fresh herbs to make herbed oils.

I am better known to be a gardener rather than a cook. As many of you are already aware, my current plant focus is on culinary herbs. At this point, I felt I should just get started on how to use them better rather than just to grow and smell them. I thought this is an ideal book to help me get started – there is information to allow me understand the characteristics of each herb which set the basis on how to use them in the most effective way in food. In my opinion, this cook book serves as a companion to complement the other herb gardening books by Jekka.

FarmVille Singapore (Gardening on RazorTV)

A group of Green Culture Singapore forum members, namely, Casey, Ting Ting and myself were featured on RazorTV. RazorTV is an online television service by Straits Times that broadcasts live from Singapore Press Holding’s (SPH) Multimedia Centre. This series of video clips focussed on the growing of edibles and is part of the publicity effort for the Singapore Garden Festival 2010. One of my team members from Hort Outreach, Jin Hong, was also in the video where she showed how one can prepare some dishes using seed sprouts.

Grow a real mini-farm! (FarmVille Singapore Pt 1)

If you’re hooked on Facebook’s FarmVille, why not bring turn that fantasy into a reality by planting your own vegetables and crops?

http://www.razor.tv/site/servlet/segment/main/94/46766.html

Tasty edible leaves (FarmVille Singapore Pt 2)

Eng Ting Ting has no need for a supermarket or market. Many of the ingredients she needs for her cooking grow right in her own backyard!

http://www.razor.tv/site/servlet/segment/main/94/46768.html

Mini kitchen farm (FarmVille Singapore Pt 3)

If you think growing vegies from home might be too ambitious, why not start off with fuss-free organic seed sprouts for salads.

http://www.razor.tv/site/servlet/segment/main/94/46770.html

Grow your own salad! (FarmVille Singapore Pt 4)

Learn how to create your own salads with easy-to-grow edible seed sprouts!

http://www.razor.tv/site/servlet/segment/main/94/46774.html

HDB mint garden (FarmVille Singapore Pt 5)

Casey Toh is hooked on growing her own edible plants, which she uses for herbal remedies and cooking. Find out why she especially loves growing varieties of mint leaves.

http://www.razor.tv/site/servlet/segment/main/94/46772.html

Look – Salad Burnet in Singapore!

I have seen the salad burnet mentioned in many herb books. A plant that is rather obscure to most Singaporeans, the salad burnet is known via a range of common names which include garden burnet, small burnet or simply burnet, it is a plant from the Rose family, Rosaceae. The common name of this herb came from the French word, ‘brunette’, referring to the chestnut red bloom. It is botanically known as Sanguisorba minor.

I got a packet of its seeds from a local seed distributor and I am happy to announce it is another herb that can be grown successfully in tropical, lowland Singapore althought it is native to western, central and southern Europe; northwest Africa and southwest Asia. In its native habitat, it grows as a perennial in dry grassy meadows with alkaline limestone soils. I grew mine in containers of 1 part of burnt earth and 1 part of mature compost which is a fairly well draining mix whose pH is near neutral, or very slightly acidic at most… Note that like many other herbs, wet feet can rot the roots of this plant.

Although it is said to be drought-tolerant, I noticed the salad burnet wilts in our tropical heat outdoors. I have since put up some shade cloth and plants seem to be happier now but still I have to water the plants twice a day to help keep their heads up on a hot day. Note that they are grown in containers with a very well draining soil mix and it is expected that the plants dry out much more easily.

I have not really tasted the leaves but it said that they taste much like cucumber and as the plant’s common name suggests, they can be used whole in salads or chopped into soups and other dishes. The youngest leaves from non-flowering plants are prefered for the kitchen as they tend to become bitter as they age. Acid soil is said to cause the leaves to take on a distinctly bitter flavour whereas plants were grown in a chalky soil produced leaves with a much milder flavour. Leaves can be dried and infused in water to make a tea.

This plant have been used medicinally. It is best known as an effective wound herb, quickly staunching any bleeding. American soldiers in the Revolutionary War drank tea made from the leaves before going into battle to prevent excessive bleeding if they were wounded. The plant’s genus name, Sanguisorba, translates loosely as “blood absorber.” Salad burnet has the same medicinal qualities as the closely related medicinal burnet (Sanguisorba officinalis). This plant is also used to treat ulcers, diarrhoea and tooth decay. Its roots are also harvested and can be made into a tea which is said to be a detoxicating agent for the body after a long-term medication or for pollution remedy.

I love the appearance of this plant for its fern-like foliage that are arranged in a rosette. It is a charming little plant with pinnate leaves where each leaflet is rounded and deeply toothed – try using the leaves for garnishing! Information about the salad burnet stated that it produces reddish-brown, erect stems with globular red flowerheads. These have purplish, feathery stigmas and sepals instead of petals. Plants are also documented to self-seed readily in areas where they are commonly grown.

The salad burnet is said to have extensive root systems and can be used for erosion control, it is also used to reclaim landfills and mined-out terrain. Amazingly, it is reported to be even able to tolerate maritime exposure!

Basil Troubles

Basil is probably the most common Western culinary herbs grown by most gardeners at home. Several cultivars of basil are grown by Singaporeans at home. Sweet basil appears to be quite common for those who cook Western food and are also fans of pesto. Those of us who are into Thai and Vietnamese cuisines would grow the Thai basil. Our Hindu friends would grow a pot of the green or purple sacred basil.

One of the most common pest problems faced by gardeners when growing basil is the infestation of the young and emerging new leaves at the growing point by sucking insects such as aphids or mealy bugs. The symptom of a prevailing infestation is quite obvious – the affected new leaves become crumpled and distorted. In some of the more severe cases that I have across, leaves can fuse into a tight mass.

Aphids and mealy bugs that cause this disfiguring symptom can only be found on the underside of the affected leaves. These small sucking insects hide amongst the folds formed in the distorted leaves and this makes the spraying of infested plants with contact pesticides rather ineffective in the eradication of these pests as it is difficult to ensure that the delivery of the chemical to all surfaces of the plant. Note that affected leaves do not recover even when the pests have been eradicated.

What I often resort to is to prune away all affected parts of the plant – cut away affected growth points down to the next healthy and uninfested node. It is essential to note that the node is still green and capable of producing new growth. Older basil plants tend to become woody near the bottom portion of the plant. Cutting such plants down to the woodier portion can prove to be rather risky as new growth may not regenerate as a result.

By pruning away infested parts of a basil plant, we are in fact reducing the number of pests that need to be eradicated. After cutting away affected portions of a plant, you may want to apply a contact pesticide to kill any remaining sucking pests and over the next few days, monitor the population of these pests. There may be a need to spray plants again after a few days to ensure the progeny of these pests have all been wiped out. Because basil is grown for food uses, I often opt to use either neem oil or white summer oil, which are more environmentally-friendly and non-toxic compared to conventional synthetic pesticides.

A beautiful but tough to grow – Crossostephium chinense

The Chinese Wormwood, botanically known as Crossostephium chinense, is a beautiful shrub to grow and is a member of the daisy family, Asteraceae. The Chinese in Singapore refer to it as ‘芙蓉菊’ which translates into ‘hibiscus daisy’, strangely. It occurs naturally in southern China, the Ryuku Islands, Taiwan and the Philippines where it grows near coastal areas on limestone and coral formations. It was once classified under the genus Artemisia.

Crossostephium chinense is admired for its aromatic, silver-coloured, furry foliage and therefore an ideal candidate for planting up a silver-theme garden. It grows as a much-branched shrub that can attain a height of 30 cm tall, adopting a bushier appearance near the ends of each growing point and older leaves are usually shed away. Older plants flower freely and produce daisy-like flowers with yellow ray florets. Fruits are seldom formed in the tropics.

Besides being an ornamental plant, Crossostephium chinense possesses some medicinal properties. In the Philippines and Thailand, an infusion of its aerial parts is documented to be used to calm the digestive system and promote the production of milk in lactating mothers. In China, it is used to treat congestions, cough and menstrual irregularities.

This plant makes a good border plant for any garden where its silvery leaves contrast against a largely green background. It is not an easily plant to grow in the wet, lowland tropics as it is very sensitive to waterlogging and prolonged wet feet. Crossostephium chinense is best planted in a pot containing well-draining, alkaline soil. Soil can be allowed to dry out a little between each watering. It should be protected under shelter during the wet monsoon season to avoid rotting of the plant. Crossostephium chinense is seldom affected by pests. It has a moderate growth rate and is best grown in a sunny spot. Because seeds are not readily available, Crossostephium chinense can only be propagated via softwood to semi-hardwood stem-cuttings.