Root Awakening: Dwarf Jasmine Orange may have dried out or lack of sunlight

Dwarf Jasmine Orange may have dried out or lack sunlight.
Dwarf Jasmine Orange may have dried out or lack sunlight.PHOTO: ALEX LONG
Plants are the Monkey’s Potato and Flame Violet.
Plants are the Monkey’s Potato and Flame Violet.PHOTO: MARIA LOW
ZZ plant is infested with scale insects.
ZZ plant is infested with scale insects.PHOTO: ALICE TAN
Tick Trefoil may be suffering from environmental stress or infected by a disease.
Tick Trefoil may be suffering from environmental stress or infected by a disease.PHOTO: MICHAEL CHUA

Dwarf Jasmine Orange may have dried out or lack sunlight

What can I do to make my plant come alive again?

Alex Long

The plant appears to be a dwarf version of the Jasmine Orange, also known as Chinese Box. Its botanical name is Murraya paniculata.

The plant appears stressed with the loss of leaves and this can be caused by the lack of water or sunlight.

If your plant has been allowed to dry out totally, massive leaf loss will usually occur. The plant can be saved provided its roots were not damaged by the drying-out process.

When growing this plant, ensure it is thoroughly watered and the growing media is kept moist at all times. Note that this plant needs direct sunlight to grow well. It grows best in an outdoor garden.

If you are growing it in a high-rise garden, ensure it gets at least six hours of direct sunlight daily. The change in light conditions from an initial brighter growing area in the nursery to a less well-lit high-rise growing environment can lead to stress and the plant will generally shed its leaves.


Plants are the Monkey's Potato and Flame Violet

What is this green plant? Is it the same as the red plant that has small red flowers?

Maria Low

The plant on the left with green leaves is known as the Monkey's Potato and its botanical name is Plectranthus monostachyus.

It occurs as a weed in Singapore where it readily disperses its seeds and grows in pots and planted areas. It is from the mint family, Lamiaceae, and related to the Indian Borage (botanical name: Plectranthus amboinicus).

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The plant on the right is the Flame Violet (botanical name: Episcia cultivar) and is related to the African Violet.

Numerous cultivars exist with leaves that are of different colours and patterns. They prefer to be grown in a moist and friable growing mix and need exposure to filtered sunlight for at least four to six hours daily.

Your plant appears to be showing poor growth with bleached leaves. These symptoms suggest it may be lacking in water or exposed to overly intense sunlight.


ZZ plant is infested with scale insects

My plants, including orchids, produce nice new leaves. But within two months, the leaves are covered with yellow spots. In time, the tips rot and the whole stem is infected. What causes this problem and how can I prevent it from recurring?

Alice Tan

The plant is commonly known as the ZZ plant (botanical name: Zamioculcas zamiifolia). The small brown spots are scale insects, a type of sap-sucking pest.

You can first remove them by brushing your plant with a soft toothbrush. Then spray a dilute solution of neem oil or summer oil weekly to keep the pest population in check.

As these pesticides work via contact, you will have to ensure you cover all surfaces of the plant with the pesticide solution.

Ensure your plant is grown under optimal conditions so that it can ward off pest attacks.

The ZZ plant grows best under filtered sunlight for at least four hours daily and it should not be over-watered.


Tick Trefoil may be suffering from environmental stress or infected by a disease

What is the name of this plant? Why are the leaves turning brown?

Michael Chua

The plant is a species of Tick Trefoil and is botanically known as Ohwia caudata. It is an obscure medicinal plant that is documented to be used in Chinese folk medicine to treat digestion-related problems.

It is an interesting plant to feature in a seed dispersal-themed garden as an example of hitchhiking - its seed pods are covered in very fine hairs and can stick to clothing and carried to new sites.

The blackening of the leaves may be caused by injury.

Was the plant suddenly moved to a very windy and/or sunny site? Excessive wind and intense sunlight can dry the leaves and cause them to show such symptoms. If this is the case, you may want to move the plant to a more suitable site.

Did you forget to water the plant and allowed it to wilt or did you spray chemicals such as pesticides or fertilisers that might have burnt the leaves?

If pesticides were used, prune the affected leaves so that new leaves can grow. If there is excessive fertiliser, water the plant more to flush out excessive salts.

Another possibility could be disease as one branch of the plant is affected. Is the plant growing in soil that is wet all the time? Disease-causing pathogens found in the soil may have infected the plant roots and stem, causing the branch to die.

Prune the infected portion and ensure the plant is growing in a well-drained media. Do give it sufficient sunlight to grow well.

• Answers by Dr Wilson Wong, an NParks-certified practising horticulturist, parks manager and ISA-certified arborist. He is the founder of Green Culture Singapore and an adjunct assistant professor (Food Science & Technology) at the National University of Singapore.

• Have a gardening query? E-mail it with clear, high-resolution pictures of at least 1MB, if any, and your full name to stlife@sph.com.sg. We reserve the right to edit and reject questions.

A version of this article appeared in the print edition of The Straits Times on October 26, 2019, with the headline 'Root Awakening'. Print Edition | Subscribe