Monthly Archives: November 2009

A weedy tree that produces delicious fruit!

A colleague of mine introduced me to this interesting fruit tree. In this part of the world, it can be seen growing just about anywhere ranging from wastelands to the neglected sides of roads and expressways. Known via a range of common names such as Jamaican cherry, Panama berry, Singapore cherry and the strawberry tree, this tree is botanically known as Muntingia calabura and is a member of the Muntingiaceae family.

Native to Central and South America, Muntingia calabura is a pioneer species, often colonizing disturbed sites in tropical lowlands. As a pioneer plant, it could help condition the soil and make it habitable to other plants. However, it might also be considered as an invasive species since it might out-compete indigenous plants.

It grows as a small, evergreen tree in the tropics that can attain a height of about 12 meters. It has a dense, characteristic tiered canopy with slightly drooping branches which cast much shade below. It grows and flowers continuously on fan-like branches where the mainline branches becoming erect after leaf fall and so in turn contributing to the formation of the trunk. This tree has furry, serrated leaves that have a sharp tip each.

The flowers of  Muntingia calabura are each borne singly and develop along a growing shoot. Flowers  are engineered to open sequentially along the elongating branch. Flowers that are about to open and those that have been pollinated are positioned differently – flowers to be pollinated are positioned above the subtending leaf so that it is rendered more conspicuous to pollinators and segregated from the concealed fruit which hangs below. This is also probably to ensure that seed dispersers going after the fruits will less likely damage the flowers.

Flowers open just before dawn and last for only a day and bees are the main pollinators although the flowers are also self-compatible. After pollination, small round fruits that resemble cherries are produced. They start out green in colour and turns into a dull red fruit when ripe. The fruits are edible and very tasty – each berry is sweet, juicy and very addictive but contains numerous tiny, yellow seeds. Humans compete with birds and bats (if they occur) for these fruits and due to this, it can be a really difficult task trying to find a ripe fruit in a tree at any one time.

Each fruit takes about 6 to 8 weeks from anthesis to develop fully and seeds are dispersed by both bats and birds. Fresh seed germination is enhanced by passage through the digestive tract of bats. The seed is well-represented in the seed banks of forest soils and requires the high temperature and light conditions of large gaps in the forest for germination; the seedlings do not tolerate shade.

Besides yielding edible fruit, flowers of this tree are used to prepare an infusion against headaches and colds in the Philippines. The pliable bark can be used as rough cordage while the soft wood is harvested and used as firewood. Due to its spreading canopy, this tree provides much shade but it may not be wise to sit beneath it, keeping in mind that there will be birds perching above, foraging for ripe berries to eat. You can expect what will rain down on you if you are sitting below!

The variegated Gardenia – for flowers or leaves?

Gardenia jasminoides (also known as Gardenia augusta) is a fragrant flowering  shrub with attractive shiny green leaves and produces fragrant white summer flowers. It is a widely cultivated garden and houseplant and can be grown in pots or outdoors in the ground as a fragrant hedge. Many varieties are now available – there those that are compact and low-growing, flowers are available in both single and double forms, as well as, plants with variegated and non-variegated leaves.

Commonly known as the cape jasmine or garden gardenia, Gardenia jasminoides is a temperate plant that is native to southern China, Japan, Taiwan and possibly also Sri Lanka. In the tropicals, it is reported to do better at altitudes of 400—1200 m. In Singapore’s hot and humid tropical climate, I noticed it prefers to be grown in a semi-shaded location outdoors. Direct sunshine in the tropics is a little too harsh for this shrub. Heat- and water-stressed plants can shed their leaves or their foliage can sometimes taken on an unhealthy yellow colour. 

In the tropical lowlands, this shrub flowers sporadically with a few blossoms each time. It thrives best in fertile and properly drained soil that is near neutral pH value. Do not let the soil dry out and the root zone should be kept moist at all times. Note that the flowers of this shrub are easily damaged by heavy tropical rains and hence it is better to try grow Gardenia jasminoides in a container which can be easily moved around during the rainy season. Interestingly, this shrub tend to flower during the rainy season and that is not surprising, as that is when the weather is much cooler. Bring a potted flowering specimen under shelter to appreciate the flowers so that the flowers don’t get damaged.

When not in flower, the dark leaves of this plant are glossy and makes an ideal foliage plant. This is achievable only when the plant is grown under semi-shade. There is a variegated version and one can see a colony being grown in HortPark’s Floral Walk. The attractive leaves of this cultivar are splashed with random swirls and patches of yellow. Unforunately, I faced much trouble trying to find and admire the flowers produced by the variegated version Gardenia jasminoides. The white flowers do not contrast well with the variegated folige backdrop. 

Not commonly produced here in Singapore, the fruits of the cape jasmine are used in China and Japan for colouring food yellow. Some extracts are commercially available in Japan and they are used to colour boiled beans, fish eggs, hot cakes, liquor, sweets, ices, noodles, candies and imitation crab. The colouring matter in the fruits contains a glycoside, which is identical with the compound called crocetin found in saffron (Crocus sativus L.). The colouring matter is a type of carotenoid pigment. However, more research is needed to prove the harmless character of the dye. The dye is also used to colour textiles yellow or scarlet.

Do you know that the fragrant flowers yield fragrant essential oils and are used in perfumery? In China, they are used for flavouring tea like the common jasmine (Jasminum sambac). Several parts of the plant are used medicinally. The roots are used against headache, dyspepsia, nervous disorders and fever while the leaves are applied in febrifugous poultices. Besides yielding colouring matter, fruits are also used against jaundice and diseases of kidneys and lungs. The seeds contain starch and an oil which is principally composed of palmatic, oleic and linoleic acid.

Going Bananas @ HortPark

Last Saturday, the heavy downpour did not seem to be successful to deter a slight excess of 40 gardening enthusiasts who gathered at HortPark’s Fruit Room to learn more about bananas. I was the speaker of the day (and hence the Banana Man) and coincidentally, I was in a shirt that had blue stripes and my colleagues who were there likened me to the character in ‘Bananas in Pyjamas’!

On top of producing delicious fruits, bananas are well known to produce leaves that can be used as environmentally-friendly food receptacles and some varieties are valued for their edible flowers and stems. To buy banana flower buds and stems for cooking, one can visit the grocery shops that are located in the shophouses near Tekka Market. Do you know that there is also a range of ornamental bananas which are grown and appreciated for their form, attractive flowers, leaves and fruits?

In that talk, I first shared with my audience the range of ornamental banana species and cultivars that can be found locally which they can grow in their gardens. They were also informed where they can buy them, as well as, see them, such as in HortPark and the Singapore Botanic Gardens’ Ginger Garden. Ivy Singh’s Bollywood Veggies is also a place to visit to see edible bananas.

I also took the opportunity to introduce to my audience the range of common edible bananas they are able to across in Singapore. They were also given tips on how to grow bananas, the common problems they will face while growing them and resources which they can look up to learn more.

The Great Tilly Gathering @ HortPark

Last Sunday, HortPark’s Fruit Room was packed to the brim with gardening enthusiasts who came to listen to Paul T. Isley III’s talk on Tillandsia, a group of plants commonly called ‘airplants’. Paul is President of Rainforest Flora which is the oldest Tillandsia nursery in the USA. We are privileged to have Paul here  in Singapore to give a talk and I must thank my members of the Green Culture Singapore discussion forum who informed me of his visit.

This is his maiden visit to Singapore and many of us felt ‘we have finally met up with the man’. The talk can be likened to be a gathering of sorts as many of the participants of the talk are well-known Tillandsia enthusiasts in Singapore, as I recognised a large handful of them. In his talk, Paul treated his audience to a colourful slideshow of many Rainforest Flora’s Tillandsia hybrids and shared with us the parentage of each one of them as well as their interesting background information.

 

Paul also revealed the news of his latest publication, Tillandsia II, which is a long-awaited and updated sequel to the book that many Tillandsia enthusiasts  grew up with. I remember seeing Paul’s earlier book, Tillandsia I, back in 1990 which was when airplants made their first appearance in Singapore. Participants of the talk also took this opportunity to bring their volume of Tillandsia I for his autograph.

Root Awakening (21 Nov 09)

As usual, asnwers to three gardening questions were given in yesterday’s instalment of the Root Awakening column. The first question asked why there were ants around a basil plant which also exhibited the drying of leaves. I suspect it could be an infestation of small sucking insects such as aphids, mealy bugs and white flies that may feed on young, emerging shoots. Attacks by these pests can cause new growth to die back.

Note that the presence of ants are a signal of a prevailing aphid infestation as they are attracted to the ‘honeydew’ secreted by aphids. Spray with neem oil or white summer oil to eradicate aphids. You may need to cut back some growth to reduce the pests before spraying.

The second question was about the appearance of flying insects in mangoes. It is likely to be a case of  fruit fly attack. These insects lay eggs while the tree is flowering. One can help to reduce the incidence of attack by constructing a fruit fly trap using a plastic bottle. Burn several holes in the middle of the bottle using a heated screw driver. Inside the cap, dangle a cotton bud soaked with fruit fly attractant (available from major nurseries) and fill the base of the bottle with some water.  Add a little cooking oil to cover the water surface to prevent mosquito breeding. Fruit flies attracted to the fruit fly attractant will visit the plastic bottle via the small holes burnt into it. Some will be trapped and drown inside the small amount of water found at the base of the bottle.

The final question dealt with the lack of fruits in a tall chilli plant. Note that chilli plants usually start to fruit when they are about 3 months old, depending on the variety as well as growing conditions. It is vital that a plant is able to receive sufficient direct sunshine (for about 4 to 6 h daily) so as to prevent the stems from etiolating.

The ‘Tomorrow Leaf Plant’

Angelica keiskei was once a popular medicinal herb in Singapore. From afar, I think it looks like a enlarged version of the flat leaf parsley plant (Petroselinum neapolitanum). In fact, do not be surprised to know that both plants are members of the Apiaceae (Umbelliferae) family. Common vegetables such as the carrot, celery and dill are also members of this family.

This medicinal herb is often sold singly in pots. It grows as a rosetted plant with a height of about 20 to 30 cm tall. Its large, much divided leaves confers a rather lush look to the entire plant. From my observation, Angelica keiskei seems to prefer to grow in a semi-shaded and sheltered location in Singapore’s hot and humid tropical climate. It doesn’t seem to be able to take our heavy, torrential rains that come down from the skies during certain times of the year here.

Outdoors, try growing Angelica keiskei in a shaded spot that is kept moist at all times. When exposed to excessive direct sunshine, this plant will wilt and turn into a sickly shade of yellow. It needs to be kept moist at all times and hence never allow the soil to dry out. Grow it in moist, fertile soil that is also free-draining.

Angelica keiskei makes a good and attractive houseplant for highrise gardeners. It does well if placed on a bright windowsill that receives filtered or reflected sunshine for at least 4 hours daily. Try to protect it from excessive wind that can dry the plant out.

Recently, I saw some specimens that are in flower on sale in a local nursery for the first time. The much branched flower spike was about 1 m tall and held numerous clusters of small white flowers. Botanically, this particular arrangement of flowers is called an umbel. Some of the flowers have even started to turn into fruits!

Native to East Asia to Japan, Angelica keiskei is known via its Japanese name ‘Ashitaba’. Locally in Singapore, people here call it ‘明日叶’ (ming ri ye) which translates into ”Tomorrow Leaf’, which refers to the ability to regenerate a new leaf soon after one has been harvested. Don’t expect it to put forth a new leaf as soon as the day after! It is not exactly a very fast grower, at least here in Singapore! If you are a fan of this plant, you probably have to have a dozen of pots to satisfy your needs!

The leaves are consumed like a vegetable either in the raw form or cooked by lightly blanching it. When cut, the aerial parts of this plant exude a yellow sap which is found to be an abundant source of furocoumarins and a range of polyphenols. These are believed to possess health-enhancing and anti-cancer properties. However, it is reported that the consumption of Angelica keiskei can lead to skin sensitivity to sunlight and may cause dermatitis in some individuals. Like many members of the Apiaceae family, Angelica keiskei also features a tap root underground that is short and thick. It is also edible and is served either in the cooked or pickled form.

Feature on NParks Annual Report 08/09

I was quite surprised to find out that my team’s (Hort Outreach) work at HortPark was highlighted in the latest annual report of the National Parks Board (NParks). The report has gone environmentally-friendly and hence electronic! One can access it via clicking on the following URL:

http://www.nparks.gov.sg/ar0809/

 The article of interest is entitled ‘Green inspiration’ and can be found under the ‘Programmes’ tab. The exact URL is as follows:

http://www.nparks.gov.sg/ar0809/prog_section/programmes-pg7.html

In the article, you will be able to read the following text: 

HortPark brings together gardening-related recreational, educational, research and retail activities.

Since its launch in May 2008, HortPark has been abuzz with programmes to encourage a greater interest in gardening. Through creative themes and colourful displays, it has been constantly inspiring gardening buffs with new ideas.

Visitors were treated to a sensorial experience in March 2009 when a showcase of perfumery plants was put on display to let the public learn more about fragrant flora.

Talks spanning a wide range of topics were also held regularly, including one on vertical gardens and another on growing insect-eating carnivorous plants.

In collaboration with HortPark, my team from Hort Outreach has been dishing out gardening-related programmes that are aimed to inspire fellow Singaporeans to take up the gardening hobby or how they can be better gardeners. Every two months, we brainstorm for ideas to put up an educational thematic showcase at the Lifestyle Corner where visitors of HortPark can browse at their own leisure. There, we also put up gardening-related products, plants and display ideas that will be useful and of interest to home gardeners.

We also conducted gardening talks regularly as well as a range of workshops such as the ‘Fantastic Terrarium’ and ‘Start Your First Plant’ that present gardening in a fun manner and it is hoped that participants of these workshops can make greenery part of their lifestyle.

Guided tours of HortPark and various theme gardens are also available for signing up! My team is currently involved in two display plots, namely, Kampong Daze (Fruit Tree and Fruited Vegetable Garden) and Herb and Spice Garden in HortPark. We are always on the constant look out for interesting plants to grow and showcase to visitors to HortPark.

Last but not least, we also help to answer gardening queries from the public and contribute articles to free NParks’ e-newsletter, My Green Space, which one can access via the following link:

http://www.nparks.gov.sg/cms/nparksenewsletter/issue3/archive/archive.html

 

The Obscure Akee Tree

Blighia sapida is an obscure fruit tree to most Singaporeans. It is commonly known as the Ackee, Akee, akee apple or Achee. Native to to tropical West Africa, it is a member of the Sapindaceae family, in which common fruits such as the rambutan, lychee and the longan also belong.

Unlike the dessert fruits we normally eat, the fruit which are produced in clusters by this tree cannot be eaten in the same way. Each fruit is shaped like a bell and starts out green in colour and turns red when ripe. The ripe fruits are used and only when they have split open into three segments, revealing three white to yellow aril covered seeds. The seeds are black and shiny when the aril around them are removed.

Note that only the aril from the ripe fruits have food uses and are used in a variety of meat dishes. Some preparation work must be done before it can be consumed. Levels of a toxic alkaloid, hypoglycin A, found in the akee aril peak at maturity but rapidly diminishes to non-detectable levels in an opened fruit making it safe for consumption.

Hypoglycin A limits the body’s ability to release of glucose that is stored in the liver and consumption of unripe or unproperly prepared akee aril gives rise to the Jamaican vomiting sickness and even death. Akee fruit arils must be first cleaned, washed and then boiled in water for at least 20 min. The water is then discarded. The boiling process helps to rid the arils of toxic alkaloids.

Akee has high nutritional value and the oil in the arils contains many important nutrients, especially fatty acids. Linoleic, palmitic and stearic acids are the primary fatty acids found in the fruit. Ackee oil makes an important contribution to the diet of many Jamaicans. The dried seeds, fruit bark and leaves are used medicinally.

The genus name of this plant was named after William Bligh of the HMS Bounty, who carried many plants to different parts of the world, this tree is grown and appreciated in Jamaica and the West Indies. He apparently took the fruit from Jamaica to England in 1793. The fruit was imported to Jamaica from West Africa before 1778. Since then it has become a major feature of various Caribbean cuisines, and is also cultivated in tropical and subtropical areas elsewhere around the world. It is the national fruit of Jamaica.

Blighia sapida is an evergreen tree that grows about 10 m tall, with a short trunk and a dense crown. The leaves are pinnate and leathery. The tree produces clusters of white, fragrant flowers and can be propagated by seed or stem-cuttings. Like many other fruit trees, the akee tree prefers to grow in a well-drained and sunny location.

Root Awakening (14 Nov 09)

In this week’s Root Awakening column, answers to three gardening questions from Straits Times Life! readers were given.

The first question was about why the flower buds of a hibiscus plant turned yellow and fall off before they blossom. Inadequate or excess watering a hibiscus can cause it to abort flower buds prematurely. It is necessary to ensure the roots are kept moist at all times during hot and dry weather. There may be a need to increase the rate of watering as well as lay a layer of compost as a mulch which can help to keep roots cool and reduce rate of evaporation.

If it is a case of excess watering, check whether your plant is potted in a well draining soil mix. One may want to incorporate some good quality burnt earth into the soil mix to increase porosity. Hibiscus plants, in general, do not tolerate prolonged wet feet. It could be due to lack of nutrients such as like phosphorus and potassium. Consider supplementing plants with a water-soluble fertiliser such as Gaviota or Phostrogen.

The next questions dealt with composting. Burying of vegetable and fruit scraps in the ground usually involves anaerobic composting and this process requires 3 to 6 months to complete, depending on a myriad of factors and environmental conditions. Kitchen waste consisting of fruit peels and vegetable scraps are termed as ‘green’ materials. Remember to add in ‘browns’ such as dried leaves into your compost pile to ensure a healthy carbon:nitrogen ratio. All materials added to the pile should be shredded into fine bits to hasten the process.

The last question was about the appearance of mushrooms in the soil. Mushrooms are fungi that sometimes emerge from moist soil that is rich in organic matter that already has some spores in it. Such fungi usually do not do much harm to your plants most of the time. One may sometimes consider changing the soil but do note that this may not be able to remove all traces of spores and fungal mycelia. Alternatively, do try to drench the soil of the affected potted plant with fungicide such as Captan to reduce the incidence of fungal emergence.

Green Living @ HortPark’s Lifestyle Corner (Part 2)

Here are more green ideas that my colleagues and I at HortPark would like to share with you… If you grow banana plants at home, why not harvest a few leaves to use as environmentally-friendly food receptacles instead of plastic ones? By doing this we can reduce the amount of waste generated whenever we have get-togethers or refreshments after company seminars or meetings. If there is a large crowd expected, one can consider buying stacks of banana leaves all cut to size from stalls in the wet market at Little India.

Kitchen scraps from plants such as vegetable clippings which are normally discarded can be used to make compost. Lately, vermi-composting is becoming a popular recycling method in Singapore. The product, Can-O-Worms (COW), is imported from Australia and marketed by Greenback Pte Ltd in Singapore. The COW kit is the black, stackable drum-like wormery which is small enough to fit into any household in Singapore (shown in the picture below).

The COW is a worm-driven recycling system designed for use inside the home. The scraps left over from preparing a meal are put into the COW where they are eaten by compost worms which live there. When done properly, the system is completely odourless and hygienic. As the scraps are eaten, they are converted to vermicast. Vermicast is an amazing product for stimulating healthy plant growth. The COW has a collector tank beneath where excess liquid is collected. This is vermicast solution and can be diluted 10 times and used as a very beneficial leaf spray. Vermicast solution will often cure fungal infestations and act as a deterrent to airborne pests and diseases.

Fruit skins can also be converted into environmentally-friendly detergent. The making of botanical detergents have also caught up in Singapore and one can make theirs using discarded fruit remains, brown sugar and water. The mixture is allowed to ferment and enzymes released during the process is said to be very efficient for cleaning chores at home. This can potentially reduce the use of synthetic detergents globally! Gardeners have also reported that such botanical enzymes are good to deter or eradicate small infestations of pests such as aphids on our garden plants!  Refer to this website for more information and following the steps on how you can make your own botanical enzyme detergent at home.