Monthly Archives: June 2009

Fruit Tree Growing in Highrise Singapore

An interesting article written on the growing of fruit trees in highrise flats in Singapore was published on the Sunday Times just over the weekend. The article shared two success stories of Singaporeans who have succeeded in growing fruit trees in the highrise environment.

In Singapore, many highrise dwellers encounter the lack of sufficient sunshine that is required for growing these plants. Either they do not get the right intensity or they receive less than 4 hours or less of direct sunshine. To grow these edible plants properly, one has to locate them in a place at home where they can be exposed to a minimum of 6 hours of direct sunshine daily. Plants not receiving enough direct sunshine will exhibit slow growth, etiolation (elongation of shoots) and lack of flowers and fruits. 

The first success story mentioned in the article focussed around Mr Lawrence Tan, who managed to grow and fruit grapes and Japanese muskmelons in tropical Singapore. Grapes have been reported before to be able to fruit here, but most of the time, the fruits are sparse and sour to taste. Muskmelons can also be grown easily without problems locally too.

The second person that was interviewed was Mr Ng Cheow Kheng, who is both my good friend, colleague and the Assistant Director of Streetscape Projects in National Parks Board (NParks). I have written a blog entry on this open patio before (viewable via this link). The two fruit trees that can be found Mr Ng’s growing area include the chiku tree and dwarf banana plant.

To be able to grow fruit trees in highrise apartments, one has to choose grafted varieties so that they can fruit while they still remain small and manageable. It is almost grow trees from seeds and expect them to fruit inside a pot. For these, they often need to attain their full height before fruit production commences. For banana plants, choose to grow dwarf varieties. By the way, bananas are totally herbaceous and are technically not classified as trees!

Slipper Orchid Feature on Straits Times Life!

I was pleasantly surprised to see a feature story written on the growing of slipper orchids being published on Straits Times Life! today. The correspondent who did the interview was Andrew Tan and the grower that was featured in his article was Mr Joseph Yeo who happens to be a veteran member of the Green Culture Singapore discussion forum. 

Like what was mentioned in the article, Joseph started his gardening interest in cacti and I remembered that he told me that he grew airplants (Tillandsia) and tropical pitcher plants (Nepenthes) before. He only started to grow slipper orchids (Paphiopedilums) only a few years ago. Similar to all plant groups he grew before, Joseph has always been fully committed to them and emerge soon after, as a subject expert.

Via his generous sharing of practical growing tips and posting of excellent photographs as a testimony of his great gardening skills on the Green Culture Singapore discussion forum, many fellow gardeners are inspired and given good guidance to grow this group of orchids which have been viewed as rather challenging to grow in tropical Singapore.

Getting to know Garcinia xanthochymus

Garcinia xanthochymus is a close relative of the tree that bears the common edible mangosteen (Garcinia mangostana) which has been crowned the ‘Queen’ of tropical fruits. Also known as Garcinia tinctoria, Garcinia xanthochymus is commonly referred via an assortment of names such as the eggtree, gamboge tree, sour mangosteen, Himalayan garcinia and false mangosteen. It belongs to the Clusiaceae family (Guttiferae).

Garcinia xanthochymus originated probably from India and Burma. It occurs in the wild, growing in the hills of South India and can also be found widely distributed in the hill forests of the Eastern Himalayas and hence the common name ‘Himalayan garcinia ‘. In Singapore, this species of Garcinia appears to be rather rare and the place where I first encountered the plant was in HortPark.

The Garcinia species is rather bushy and adopts a rather attractive, pyramidal growth habit that can be likened to a Christmas tree. Its large leaves are linear in shape, dark green, thick and leathery in texture and they hand down from the stiff branches that extend outwards in all directions from the main trunk. It is a slow-growing tree like many other Garcinia species and can attain a height of 10 m.

Like other species in the same genus, male and female flowers usually occur on separate plants. Garcinia xanthochymus  is observed to produce both male flowers and bisexual (hermaphrodite) flowers in clusters. The latter can be distinguished by their longer longer axils. The bisexual flowers apparently self-pollinate so that fruits can form.

Unlike what one of its common name ‘eggtree’ suggests, the fruit of Garcinia xanthochymus  is not egg-shaped. The fruit has a curved pointed end which makes it look like an inverted tear-drop. Like the common mangosteen, one can find persistent sepals and staminal bundles even on a mature, ripe fruit of Garcinia xanthochymus.

Fruits produced by Garcinia xanthochymus are green when young and they turn bright yellow when ripe. They look extremely tempting and are often reported to have a juicy pulp with a pleasant acid flavour and can be eaten out of hand. I beg to differ on this as I find the pulp extremely sour and not pleasant at all! It is no wonder that the fruits can be used as a tamarind substitute in cooking. Another species, Garcinia atroviridis, bears fruits that are used in the same way. Inside each fruit, there are two brown, oval-shaped seeds.

The fruits of  Garcinia xanthochymus are also made into preserves and jams and used for making vinegar. They can also be dried so that they can be stored for a longer time and used later. A sherbet made from the dried fruits is given in bilious condition. An inferior yellow coloured gamboge that has uses as a dyestuff is obtained tapping its stems or extraction from the fruit rind. 

Garcinia xanthochymus is relatively easy to grow. Like many other Garcinia species, young individuals should be given shade when young. Plants should be given ample amounts of water during the hot and dry season. When established, this tree grows very vigorously and can adapt to a variety of soil types. It usually starts to produce fruits about 5 years after seed-sowing.

Ornamental Flowering Shrubs from Acanthaceae on the Serangoon Newsletter

My contribution to the May 09 issue of the bimonthly Serangoon newsletter focussed on four selected beautiful flowering plants from the Acanthaceae family. The Acanthaceae family consists of numerous ornamental shrubs that feature rather long-lasting, showy and colourful inflorescences. The durability of inflorescences is due to the bracts and not the often insignificant, tubular flowers that the plants produce. Some members of this family of plants are also medicinal.

The four plants that were featured include the shrimp plant (Justicia brandegeana), lobster claw (Ruellia colorata), Golden Plume (Schaueria flavicoma) and lollipop plant (Pachystachys lutea). They can all be found growing in various parts of HortPark (NParks’ Gardening Hub for Singapore) such as the Home Garden and Golden Garden.

These four flowering shrubs should be grown in an area with direct sunshine for at least half a day that has soil that is fertile and well-draining. They will not thrive in waterlogged areas. Do also prune periodically when plants start to look straggly as this will help to ensure a compact and attractive growth form and rejuvenate them. Fertilise shortly after a hard prune to give plants a good kickstart again.

From what I have noticed, they fare better outdoors probably due to longer availability of direct sunshine. When grown in on a sunny balcony, plants can receive direct sunshine ranging from 4 to 6 hours daily. That is likely to be insufficient as apartment gardeners I have come across had lamented that their plants tend to grow rather straggly and etiolated and flower production had been poor. 

Readers are to note there are some errors in the article due to my late returns to my Editor. The corrected article is shown above and its corresponding pdf file can be downloaded via the following link:

http://www.greenculturesg.com/articles/may09/acanthaceae_SGNL.pdf

Root Awakening (20 Jun 09)

Another Root Awakening column for the month of June 09 was published. This week, answers to three gardening questions were published.

The first enquired about white oil spray and how one can make some homemade pesticide spray for use on plants. White oil is basically is petroleum oil that is available in aerosol can form that is often applied as a leaf shine on plants. This oil can also be used in the same way like white summer oil (with emulsifier included) or super summer oil (without emulsifier) to control the populations of small sucking insects such as whiteflies, aphids, spider mites and mealy bugs upon contact.

A variety of  homemade sprays can be made. The most common being chilli and garlic spray which can be concocted at home using some chillis and garlic pounded to yield a juice which is then mixed with some detergent and then sprayed onto plants. The insecticidal power of such a concoction is limited and is quickly washed away by rain and broken down by intense direct sunshine.

The second question dealt with the appearance of yellow leaves in hibiscus plants. It is a very common occurrence in Singapore and can be brought about by iron deficiency. One has to correct the underlying causes that led to this and this include excessively wet or compacted soil, root rot disease, nematodes or elevated soil pH. Feed with a water-soluble fertiliser that contains chelated iron. Phostrogen is a good one to try.

The last question was about distorted leaves seen on bird’s nest ferns and basil plants which I reckon could be caused by thrips or spidermites. These tiny pests like to attack the young and tender new leaves of many plants which go unnoticed by most gardeners due to their very small size. The damage manifests itself as distorted leaves when the affected leaves grow larger with time. Spidermites can be eliminated using repeated sprays of white summer oil but thrips can only be killed by using the more toxic and systemic pesticide called Confidor. The use of the latter is discouraged on edible plants such as basil.

The Indian Lettuce

The Indian lettuce is an edible leafy vegetable that is quite prevalent in Singapore’s community gardens. Botanically known as Lactuca indica, the Indian letttuce is a member of the daisy family, Asteraceae and related to the common lettuce (Lactuca sativa).

This vegetable is not available for sale commercially in Singapore and only the more senior gardeners are probably the ones who are familiar with it. They called it the “goose vegetable” (鹅菜) because the greyish green leaves were reportedly harvested and fed to geese several decades back when Singapore still had villages and farms.

Native to warmer parts of China, Taiwan and southern Japan, the Indian lettuce is thought to be introduced to this part of the world by Chinese immigrants. The plant is a perennial which sends up new shoots from the base of the plant. It adopts a rosette growth habit when young and depending on the cultivar, the leaves of this plant can range from simple, undivided to deeply pinnated. The one seen locally produces oblong-lanceoate in shape. There is a cultivar with prominent red mid-ribs.

 With time, one will notice the leaf to leaf distance on the stem elongates and the leaves start to get narrower and shorter as well. When the plant attains a height of about 1.5 to 2 m, it will start to send up its inflorescence. The inflorescence is much branched and the daisy-like flowers each resembles a poached egg, complete with a yellow center and white rays. Growth terminates for that particular shoot and the plant spends its energy to produce seed. The plant sometimes sends up new sideshoots from the base.

Seedheads form after the flowers fade. One will be able to find numerous small and black coloured seeds loosely clustered around each seedhead. Each seed is flat, hard, black in colour and has some interesting-looking fluff that is attached to it on one end. With that characteristic, seeds of the Indian lettuce appear to be wind-dispersed. To grow this plant, one has to start from seeds but these are not available commercially as well. It is best to get fresh seeds by approaching a gardener who is growing some Indian lettuce plants in his/her garden.

 

The leaves of the Indian lettuce are not particularly nice to eat and are rather coarse in texture. When injured, the wound exudes a white latex. In my community garden, the Indian lettuce is grown like a cut-and-come-again vegetable where the leaves located lower down on the stems are harvested while leaving the plant to continue to grow. We do not uproot the entire plant for food. Besides being edible raw, steamed and boiled, Indian lettuce leaves have medicinal uses too. According to Plant Resources of South-East Asia (PROSEA), they are believed to possess tonic, digestive and depurative properties.

Contribution to Singapore CHild Magazine (Jun 09 issue)

My contribution in the capacity of a staff member of the National Parks Board (NParks) to the Singapore Child magazine’s June 09 issue was recently published. The article where my comments appeared is entitled “Your Budding Green Fingers” and can be found on page 50. The reader will also find inputs from Shirley Ling, one of my fellow colleague from NParks’ Community in Bloom.

In the article, I shared that gardening is a good activity that can bring people together, teach children about food production, sustainable gardening and environmental and wildlife issues. When working in the garden, adults should be around to supervise the usage of sharp cutting tools. Children should not be allow to run around with them or play with them. Kids can also be encouraged to turn everyday items into equipment that can be used in the garden.

The reader will also be able to find useful tips on growing plants indoors. Sunlight is perhaps the most important factor that is often taken for granted. To grow edible and many flowering plants successfully, it is essential to locate them in an area with at least 6 hours of direct sunshine. For container gardening, it is advisable to buy premixed potting mixes. Soil taken from the garden is often too clayey and heavy which compacts over time and harbour undesirable organisms. To feed plants, chemical fertiliser pellets may be a better choice compared to organic ones due to the fact that the latter may emit objectionable odour and attract critters.

‘SPICE’ up your life!

For the month of June, visitors to the Lifestyle Corner at HortPark had the chance to savour the sight and smell of more than 30 types of common and exotic dried spices in a special showcase of spices. They were also able to view various live spice plants, such as the pepper vine, clove, candlenut and asam gelugor trees on the Timber Deck.


Spice showcase at HortPark Lifestyle Corner.
  


Wilson sharing facts on spice gardens with the audience.

 In conjunction with the showcase, a talk-cum-demo entitled “SPICE up your life!” was conducted on Saturday (13 Jun 09). More than 30 participants turned up and learned interesting facts about spice trees and how to set up a simple spice garden. Spices such as clove, nutmeg and candlenut and leaves from their respective trees were passed around during the interactive session for the audience to take a closer look.


Leaves and fruits from spice trees were passed around in the audience.

 

Students from Teck Whye Secondary School Art Club showing the making spice pouch magnets to the audience.

Students from Teck Whye Secondary School’s Art Club also gave a demonstration that taught participants how to make attractive spice gifts using spices. At the end of the session, each participant received a spice magnet as a parting gift and was then brought on a guided tour of the Lifestyle Corner.

Fragrant spice ornaments you can display in your house.

You can still view the spices showcase at HortPark even after the month of June as the entire collection will be relocated permanently in the kitchen section of the Lifestyle Corner. So come down to HortPark and ‘SPICE up your life’ with us! Spices will never be the same again!

Root Awakening (13 Jun 09)

The Root Awakening has increased its frequency. Instead of appearing every alternate week, the column will now be published on every weekend!

This week’s column offered answers to three gardening questions. The first one shed some light on the growth habits of succulent plants from the genus Agave (or Furcraea) which are popular landscaping plants here. These plants are rather long-lived but they do produce flower spikes when mature. When they do, they flower terminally and the mother plant dies. The plant produces numerous baby plants that perch on the branches of the flower spike and these can be used for propagation.

As these plants are spiny, it is best to avoid growing them in high traffic areas. Although I do not know that the spines contain any toxin, any cut or abrasion caused by spine on the skin can introduce pathogens into one’s body.

The second question dealt with the dumbcane plant. This plant is a popular foliage houseplant once in Singapore. Due to reduced evaporation rates indoors, it is best to water the dumbcane plant only when the soil feels a little dry. Overzealous watering indoors can lead to a variety of problems such as rotting of stems and fungal leaf spots. One of the early signs of overwatering that can arise will be the yellowing of the plant’s lower leaves.

The last question was about the passionfruit. When the plant is fruiting, it is best to keep the soil moist at all times. Any form of moisture-stress, such as underwatering or overwatering, can lead to the loss of developing fruits. In such a case, young fruits will be aborted from the vine.

Alpinia galanga in bloom!

Alpinia galanga is a member of the true ginger family, Zingiberaceae. The fresh underground rhizomes of this ginger are readily available for sale in Singapore markets. Two types of rhizomes are available for sale. The tender younger rhizomes which appear pale pink, have a less intense flavour compared to the very tough, older and beige coloured ones. The rhizomes of this ginger are too spicy to be eaten raw and are used in slices, chunks or pounded to give a paste and used to flavour various curries and other dishes. Besides the rhizomes which have uses in the kitchen, the immature lateral shoots and unopened flower buds of this ginger are edible when steamed.

The rhizomes of Alpinia galanga are also used widely in folk traditional medicine. According to the profile found in Plant Resources of South-East Asia (PROSEA), the rhizomes are used in the treatment of skin diseases, respiratory diseases, as a stomachic after childbirth, for intestinal problems and as an expectorant and aphrodisiac. The seeds are prescribed in Peninsular Malaysia in colic, diarrhoea, vomiting and herpes. An infusion of the leaves is taken as a post-partum medicine.

Botanically, Alpinia galanga is sometimes referred to as Languas galanga. The common name Alpinia galanga is the greater galangal or lengkuas. Its Chinese names include “大高良姜” and “红豆蔻”. Singaporean Chinese here call the rhizomes simply as “lam kew”, which translates into “blue ginger”, although no part of this ginger is blue in colour!

A native of South Asia and Indonesia, the Alpinia galanga  plant is easily grown from rhizomes and is a commonly grown ginger plant in the gardens in Singapore. One can always find it in any herb and spice garden here. The plant is not exactly ornamental although it features rather lush, green, leafy shoots with lanceoate leaves that grow in a tight clump. Each shoot can grow up to 1.5 to 2 m in height. The plant is not exactly invasive.

When left to grow, an Alpinia galanga plant will actually produce flowers. Numerous flowers are borne on an erect spike. Each flower is rather small, reportedly to be fragrant and pale yellow in colour with a distinctive white lip that is adorned with a red center and a prominent pale green or white stamen. Although seldom seen to produce fruit here, the plant is reported to bear red coloured fruits that are used in traditional Chinese medicine and has a flavour similar to its rhizomes.

 Although most ginger plants are thought to grow better in semishaded locations, Alpinia galanga is one plant that thrives when given more light. I have observed that this plant will tend to produce more sturdy leafy shoots when grown under full sun. Previously, I have some plants that were growing in semishaded locations and they were observed to put forth rather floppy leafy shoots.

Newly acquired plants may need some time to adapt to higher light levels. Initial planting will experience some burnt leaves. It is essential to provide plants with ample moisture at the roots when they are grown out in the open. Some organic mulch placed around the root zone will be beneficial.