Root Awakening (18 Dec 2010)

Answers to three gardening questions were provided this time round. The first question was about the identity of a weed. With the help from the Singapore Herbarium, the plant was indentified to be Pipturus argenteus and commonly called the ‘native mulberry’. Note that it is not related in any way to the mulberry (Morus species) that are often grown in local medicinal gardens.   Pipturus argenteus grows naturally in Australia and is a host plant of the Malayan Eggfly caterpillar (Hypolimnas anomala anomala). Plants are dioecious where male and female flowers on separate individuals. It is difficult to raise from cuttings, so seeds are probably the best way to grow new plants.

The second question was about ‘local’ pomegranate plants producing small fruits. Note that most of the pomegranate plants sold in local nurseries are the small fruited, ornamental varieties. Most Chinese here regard the pomegranate plant as a ‘lucky plant’ and grow it as a potted plant for its decorative value. Edible, larger-fruited varieties are hard to come by here.

The last question enquried where one can procure Gynura procumbens which is a plant that is thought to possess medicinal properties. The best known property is the plant’s ability to reduce high blood pressure and blood glucose levels. In Singapore, one can visit and buy a pot of this herb from Hua Hng Trading Company Pte Ltd located at 15, Bah Soon Pah Road, Singapore 769962.

Root Awakening (17 Apr 2010)

Below are the answers to two gardening questions that were published in the Root Awakening column on Straits Times Life! on 17 April 2010.

The first question was about the browning of leaves and subsequent decline that were observed in palms growing indoors. Note that palms are best grown in a sheltered, semi-shaded location at home. Depending on the species, most ‘indoor palms’ are best situated in a location such as the balcony or corridor where the leaves can receive at least 6 hours of filtered sunshine daily.

If one is growing it deep indoors, attempt to rotate the palm plant with another plant in a brighter location. A plant grown deep indoors will not receive sufficient sunshine and will decline over time. Avoid disturbing the plant’s root ball too much when you attempt to move it to another pot. Mishandling can bring about excessive damage to the roots can cause a plant to experience transplant shock. A newly transplanted plant should be moved to a shady place protected from excessive winds for at least a week to help recovery.

The next question was about the growing of the cat’s whiskers plant and how to get it to bloom. Note that the cat’s whiskers plant is a sun-loving plant. It grows best if it is grown in a sunny area with at least 6 hours of direct sunshine. Check the duration of sunshine that one’s plant is receiving. Prune plant back abit after flowering as this has been noticed to promote the production of new flowers. Next, do feed plants with a fertiliser for flowering plants. Avoid feeding plants with fertiliser rich in only nitrogen as that will promote the production of leaves over flowers.

Root Awakening (10 Apr 2010)

In this week’s Root Awakening column, answers to three gardening questions were given.

The first question was about the lack of growth observed in begonia plants. Note that begonias demand a cool, bright, moist but well-ventilated area to grow well. Begonias that are grown in a high-rise apartment can have their growth affected adversely if they are grown in an area with direct sunshine or too windy. Locate them in a semi-shaded area that is protected from winds as winds can dry the plant out.

The second question enquired about the lanky growth of the devil’s backbone (Pedilanthus tithymaloides). Note that this plant likes to be grown in a sunny location. When grown in the shade, plants tend to become straggly and lanky. You can trim back the plant and locate it to a sunnier location to regenerate. Use the tip-cuttings as propagation material. The white milky sap is poisonous, so avoid contact with the skin.

The last question dealt with the method of propagation for the Crown of Thorns plant. This popular houseplant is easily propagated from tip cuttings. Take stem tips of about 10 cm in length and it is essential to allow the milky sap flow to stop before you proceed further. You can dip the end the cut end in water until the flow of sap stops. After that, allow the cuttings to dry in air for another three to four days. Then coat the cut end with a rooting hormone and stick it into some well-drained soil mix. The mix should be kept just slightly moist and not sodden. Stem-cuttings should root within a month.

Root Awakening (3 Apr 2010)

Below are answers to three questions for the Root Awakening column published on 3 April 2010.

The first question asked why the leaves of mint and basil started to curl with the presence of ants around the plants. Note that the curling of these herbs’ leaves is a sign of aphid or mealy bug infestation. When leaves are distorted, they cannot regain to their normal look and form again. What is recommended is to trim the affected parts away to the nearest node on the plant. The plant will regenerate with new growth with application of fertiliser. Control the population of ants and look out for any remaining infestations. Spray plants thoroughly with dilute soap solution, white summer oil or neem oil. Mint demand a sunny location with soil that is kept moist at all times to flourish. The hot and dry season with winds can cause plants to dry out quickly. Check that plants are not pot-bound as this will restrict their uptake of water and nutrients. Water plants well to keep them hydrated during this time.

The second question was about the growing of the recently introduced ‘lucky’ plant called the ‘Little Bird Plant’ which is a drought-tolerant plant from Central America and one should avoid overwatering it. Soil should be well-draining and kept barely moist at all times. It likes a sunny spot to grow well and situate it in a location with direct sunshine for at least half a day. For more information, look up via its botanical names – Pedilanthus coalcomanensis or Euphorbia coalcomanensis.

The last question was about the growing of a durian seedling. The reader described that the seedling started to turn brown after transplanting. What the reader did probably disturbed/damaged the roots of the durian seedling when you are trying to transplant it into a larger pot. The seedling can experience transplant shock if the operation was not done properly. Seedling should be well hydrated before transplant and if possible, the entire root ball should not be disturbed and transplanted whole into its new pot. After which, the plant should be located in a cool, bright and windless place soon after transplant for the plant to recover for at least 2 weeks. Also, soon after transplant, avoid adding fertiliser right away and this can be done about one month after transplant. When applying fertiliser, avoid placing the pellets too close to the plant’s roots and stems as they can burn the tender plant tissues.

Root Awakening (20 Mar 2010)

Below are my responses to 3 gardening questions published in the last instalment of the Root Awakening column for Mar 2010.

The first question asked why the flower buds of a new pot of African violet had turned brown. Note that newly imported African violets from a cooler area may be shocked when they arrive in hot, tropical Singapore and this will cause its flower buds to turn brown. Also, avoid wetting the flower buds and locate the plant in a bright and well-ventilated area at home/office. Remove dead flower buds promptly by cutting the flower stalk at the base.

Plants are often potted in a peat-based substrate and that can retain too much water. You may want to carefully transplant the plant after all flowers have faded by first removing the soil around the roots and repotting it in a better draining soil mix. You can buy a commercial African violet mix and combine 1 part of this mix with 1 part of perlite and 1 part of vermiculite to enhance drainage.

African violets often rot when they are over-watered. You can water them via the saucer method and water only when the soil mix feels dryish and you can do this by poking your finger into the soil mix to feel for moisture.

The second question was about the care of a potted pussy willow plant bought during the Lunar New Year. The reader reported that water flowed straight out from the pot when he tried to give water to the potted plant. Water probably flowed out as the root ball has dried and caked up and hence does not permit water to infiltrate it. In such a case, one would need to soak the root ball in water to thoroughly moisten it. Since the root ball is wet, withhold watering for the next few days and situate the plant in a well-lit and well-ventilated area. Don’t allow the root ball to dry out totally again. Note that pussy willows are trees belonging to the temperate climate. They won’t do well in Singapore and are not rewarding to grow here. It is best treated them as festive plants for decorating the home for Lunar New Year which can be discarded when they start to decline.

The last question asked how one can propagate the torch ginger plant. The part of the torch ginger plant that is sold in the wet market is its unopened flower buds which are used for rojak. That cannot be used for propagation of the plant. Rhizomes of this plant are not used in food and are hence not sold in the market. One can visit any large nursery to buy a young plant to grow. Remember to grow this plant in a semi-shaded area in the ground with soil that is fertile and kept moist at all times. Avoid a windy area. Plants should flower in 1 to 2 years if well-taken care of.

Root Awakening (13 Mar 2010)

Below are my answers to three gardening questions to the second instalment of the Root Awakening column for Mar 2010.

The first question asked about the identity of a tree found growing in the vicinity of the Regent Hotel on Cuscaden Rd, Singapore. That tree is a popular landscaping candidate that is commonly called the ‘Happiness Tree’ and ‘Philippine fortune tree’. It thrives in semi-shade and well draining soil conditions. Botanically known as Garcinia subelliptica, it is a close relative of the common mangosteen and is a slow-growing, medium-sized tree with evergreen, thick and leathery oval leaves. It has one main trunk and adopts a compact and conical crown. Interestingly, it was once planted to form a windbreak in the Okinawa islands, Japan.

The second question asked about a problem – yellowing leaves – encountered during the cultivation of a chilli plant. It is important to ensure that one’s chilli plant is well hydrated at all times. Plants that have suffered severe drought conditions often develop yellowing leaves which are shed subsequently. There may be a need to water your plants more than once daily if it is grown in a windy and sunny location.

One may also want to take the plant out of its pot to check for soil mealy bug infestation as these pests impair a plant’s ability to uptake water. When there is a prevailing infestation, the roots of your plants will have white patches surrounding them. A safe and organic but rather slow method that can be used to treat infested plants is to use diatomaceous earth (available from Known You Seeds (S.E.A.) Distribution). Diatomaceous earth is an inert, non-volatile, powdered substance made from the skeletal remains of diatoms, which have been processed to form razor-sharp particles which cut into the bodies of small insects. Avoid breathing in the dust.

To treat for soil mealy bugs, carefully wash off infested soil from your plants roots and then repot your plant in a soil that has been mixed with diatomaceous earth. Use about 1 tablespoon per one liter of soil. Note that large chilli plants can suffer from transplant shock during the root washing process.
Soil mealy bugs can be difficult to eradicate and badly affected plants should be discarded. Sterilise pots and soil before using them to pot up new plants.

The last question was about mosquito plants. Note that no plant (common ones include Pelargonium citrosum and citronella grass) in existence will repel mosquitoes by sitting in a pot or a corner in a garden. Many plants touted to repel mosquitoes are due to the fact that they have significant amounts of repellent essential oils in their leaves. The repellent effects will only be observable when their leaves are crushed or heated where the essential oils are released into the air.

Root Awakening (20 Feb 2010)

In this weekend’s Root Awakening column, answers to three gardening questions were given. The first question dealt with the spraying of pesticides by our neighbours. Note that pesticides vary in terms of their toxicity and all should be treated as harmful. One should advise his neighbor to inform him whenever a pesticide application will be performed so that the necessary precautions can take place. It would also be useful to know the type of chemical that is being applied so that you can do some homework to know what protective measures to take. Some pesticides are very toxic to fish and aquatic life so make sure pesticide fumes do not reach them.

The next question was about a local medicinal herb, which is botanically known as Gynura procumbens. It is a plant that is a member of the daisy family, Asteraceae, which is eaten as a leafy vegetable in some parts of the world. To date, its cancer-curing properties have not been systemically assessed and proven. This plant is also believed to be able to reduce high blood pressure and lower serum glucose levels, amongst others. Further studies need to be performed to confirm such effects. It is best to consult a certified practitioner before consuming such herbs.

The last question queried about the identity of a houseplant with purple foliage. Botanically known as Oxalis regnellii ‘Atropurpurea’, this particular houseplant is known via a range of common names that include Purple Oxalis, Wood Sorrel and False Shamrock. It is native in Argentina, Bolivia, and Paraguay and can be propagated via division of the crown. Grow it in a protected, semi-shaded location away from winds. It prefers to grow in a well-drained soil mix such as one concocted for container gardening. Keep soil moist at all times and not soggy. Fertilize weekly with a balanced fertilizer.

Root Awakening (13 Feb 2010)

Three gardening questions were provided with answers for this week’s Root Awakening column. The first question dealt with the choice of fruit trees that are suitable for growing in a rooftop garden in Singapore. For this, I suggested some small fruit trees that are more rewarding to grow in pots which include the chiku, kedongdong, guava, jambu and starfruit. Grafted versions of the mango can also be considered. Another fruit plant to grow is the dwarf Cavendish banana. It is important that fruit trees should be located in a location where they are able to receive at least 6 hours of direct sunshine and soil that is kept moist at all times. Note the weight bearing capacity of one’s roof-top before populating the area with large pots of fruit trees.

The second question was about the choice of plants for a east- or west-facing growing location and the range would largely depend on the duration and intensity of sunshine that are available. If the area receives direct sunshine for at least 4 hours daily, one can grow a large range of plants which include flowering shrubs and vines and selected vegetables and herbs. Fruit trees can be difficult as they require longer duration of direct sunshine.

Note that many foliage plants need some form protection under such high light conditions to prevent foliage burn. They can be grown on the lower tier of your growing rack or between taller plants which can offer some shade from direct sunshine. I referred readers to grab the book entitled ‘1001 Garden Plants of Singapore’ published by the National Parks Board for the range of plants that one can grow in a balcony. The light requirement of each plant is indicated by an icon in the book.

The last question was about the lack of fruit set in tomato plants. This is a commonly encountered problem in Singapore. It is important to note that not all tomatoes will be rewarding to grow in Singapore’s climate. Only the smaller fruited cherry tomatoes seem to set fruits well here. Larger fruited ones usually experience poor fruit set as flowers tend to drop off without turning into fruits. To help pollination, it may be beneficial for one to perform hand pollination by using a fine paintbrush to brush each opened flower to help transfer pollen which will increase the chance of fruit set.

Note that the first few flushes of flowers tend to be aborted but fruit set should start soon after that.

Root Awakening (23 Jan 2010)

The third and last instalment of the Root Awakening column for Jan 2010 was published today.

The first question was about the growing of hibiscus plants from stem-cuttings.  Hibiscus can be propagated via both softwood and semi-hardwood stem-cuttings. Softwood cuttings are taken from soft, succulent, new growth. Shoots are suitable for making softwood cuttings when they can be snapped easily when bent and when they still have a gradation of leaf size (oldest leaves are mature while newest leaves are still small). They usually root faster than semi-hardwood cuttings.

Semi-hardwood cuttings refer to stems taken from partially mature wood. Such stems are reasonably firm, the leaves of mature size and may have some bark on them. Avoid material with flower buds if possible and remove any flowers and flower buds when preparing cuttings so the cutting’s energy can be used in producing new roots. Take cuttings from healthy and disease-free plants. Take stem-cuttings from plants that have been well-watered and do so in early morning when it is cooler.

Cuttings are best around 4 to 6 inches long by using a pair of sterilized sharp pruning shears. Remove the leaves from the lower one-third to one-half of the cutting. Cut large leaves in half to reduce water loss. Dip the cut end of a stem-cutting with some rooting hormone powder made into a slurry.

Stick stems into a new soil mixture that is sterile, low in fertility, and well-drained to provide sufficient aeration. Insert the cuttings one-third to one-half their length into the medium and maintain the vertical orientation of the stem. Cover the cuttings with a plastic bag and place in indirect light. Keep the medium moist until the cuttings have rooted. Rooting will be improved if the cuttings are misted on a regular basis.

Rooting time varies with the type of cutting, the species being rooted, and environmental conditions. Grow cuttings in a pot until they attain a larger size before transplanting to a permanent location.

The second question was about the shrivelling of leaves of a tree. It could be due to hot and dry weather. Under such weather conditions, it may be beneficial to ensure the plant is well-watered and roots are kept moist. Do also apply a layer of mulch around the root zone to ensure it stays moist and cool. If possible, provide some form of shade during this period. It could also be due to a bout of insect infestation and hence it would be necessary to check if there is any and ensure that all pest infestations have been cleared. Any remaining population can re-infest a plant if not properly eradicated. Several rounds of pesticide application may be necessary.

The last question was about the pruning of a money plant. A money plant will not die if its growing tip has been cut. The plant will respond by producing side shoots and this can take any time at least two weeks, depending on the growing conditions. Cutting back a money plant can be beneficial at times as it helps to keep a plant’s growth in check and can help to maintain or promote a bushier growth habit.

Root Awakening (16 Jan 2010)

The second instalment of the Root Awakening column for Jan 2010 was published yesterday. As usual, answers to three gardening questions were provided.

The first question was about the growing of the flaming beauty (Carphalea kirondron), which is a sun-loving shrub that is also a heavy feeder. It prefers to be grown in consistently moist soil that is enriched with well-rotted compost. One has to watch out for 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. Spray with neem oil or white summer oil to eradicate these pests.

The second question was about a reader’s proble in growing of a rose said to be from Kunming. Note that the rose plant needs to be protected from the tropical mid-day sun. Roses like to be grown in a sunny area with moist, well-draining, fertile soil that is supplemented with organic matter such as compost. One can fertilise plants with a suitable rose fertilizer or water-soluble ones like Gaviota and Phostrogen, made up according to the manufacturers’ instructions. Heat can be a serious problem with roses during the hot season where new shoots and buds can dry up as a result. Grow in pots so that it is easier to move plants to semi-shaded areas during that time.

Also, rose plants are commonly affected thrips or spider mites that commonly attack young growth and new flower buds of rose plants. To eradicate these pests, Condifor (active ingredient is imidacloprid), which is a systemic pesticide has been found to be particularly effective. Before spraying, it is best to prune away affected parts so as to reduce the population of pests.

The last question dealt with the lack of flowers of a yellow frangipani plant. Note that this plant is a sun-lover and one has to ensure his/her frangipani plant receives sufficient duration of direct sunshine. A recommended duration would be at least 6 hours daily. It would be beneficial to feed the plant with a fertiliser to promote flowering that is high in phosphorous content. Refrain from fertilizing your plant with only organic fertiliser which is usually rich in nitrogen that promotes growth of foliage. Make sure that the soil pH is right so that nutrients required for growth are not locked up or in excess which will affect the plant. The optimal pH range for frangipani is from 6.4 to 6.8.