Root awakening

BougainvilleaPHOTO: PAUL KWEK
Leaves of Chinese Violet
Leaves of Chinese VioletPHOTO: S.R. MARY
Durian tree
Love-in-a-mistPHOTO: H.K. LEE
Water lily

Bougainvillea needs full sun to flower profusely

How do I get my bougainvillea plant to flower? It gets the morning sun, but is blocked from the afternoon sun by two huge overhanging trees. I trim it regularly and feed it fertiliser.

Paul Kwek

There are a number of factors affecting the shy blooming of the bougainvillea plant.

The plant is best grown outdoors where it can be exposed to full sun every day. Exposure to the morning sun alone may not promote profuse flowering.

Avoid using a fertiliser with an excessive amount of nitrogen. This will cause the plant to produce more leaves instead of flowers.

Instead, use a fertiliser that will encourage flowering.

Also, reduce the amount of water you give your plant. A brief dry spell may trigger profuse flowering.

Leaves of Chinese Violet are food for caterpillars

What is the name of this plant? It grows rapidly and has small, white flowers with purplish-blue centres.

S.R. Mary

This plant, which has the botanical name Asystasia gangetica ssp. micrantha, is a weed. It is known by a few common names such as Common Asystasia, Chinese Violet, Creeping Foxglove and the Ganges Primrose.

Despite being a weed, this plant has an important ecological role. Its leaves are food for caterpillars of butterflies such as the Great Eggfly, Autumn Leaf, Blue Pansy and Jacintha Eggfly.

To encourage butterflies to lay eggs in your garden, do not use too much pesticide.

Durian tree has long, narrow leaves with sharp drip tips

Is this a durian tree?

James Loh

The flowers on the tree look like the blooms of a durian tree, which is known botanically as Durio zibethinus.

The flowering habit of the durian tree is described as ramiflorous, where clusters of its flowers grow along its big branches. Flowers of the durian are known to be pollinated by bats, so urban dwellers should not chase the bats away.

The durian tree has distinctive long and narrow leaves with sharp drip tips and bronze undersides. The tree grows naturally in a conical form, but pruning it may alter the tree form.

Fully ripe fruit of love-in-a-mist are edible

What are these creepers and are its fruit, which have a texture similar to passionfruit, edible?

H.K. Lee

The vine is botanically called Passiflora foetida and is a species of passionfruit. Its common names include stinking passionflower and love-in-a-mist.

Its species name, "foetida" - it means stinking in Latin - refers to the strong odour emitted by the plant's damaged parts. This species often occurs as a weed and grows on vacant land.

Still, it has important ecological uses in the urban landscape, where its leaves are food for caterpillars of the Tawny Coster butterfly. Hence it is often grown in local butterfly gardens.

Its fruit are safe to eat only when they are fully ripe, which is when the skin is dark orange. It is said that the plant also has medicinal uses and various parts are used to treat ailments such as colds and chesty coughs.

Water lily has fungal disease

What are the brown spots on the leaves of my water lily? Will this spread to the other lilies in the pond? How do I get rid of the spots?

Seh Wah Lim

The water lily (its botanical name is Nymphaea hybrid) is suffering from a fungal disease. This is a common affliction for this plant.

In a water feature where there are fish and other aquatic organisms, you should avoid using fungicide to control the water lily's fungal disease. The most environment-friendly way would be to promptly remove the infected leaves and discard them with the trash.

Never compost these leaves as the fungal infection may spread to other plants when the compost is used.

•Answers by Dr Wilson Wong, a certified practising horticulturist and founder of Green Culture Singapore ( He is also an NParks-certified park manager.

•Have a gardening query? E-mail it with clear, high-resolution pictures of at least 1MB, if any, and your full name to

A version of this article appeared in the print edition of The Straits Times on November 11, 2017, with the headline 'Root awakening'. Subscribe