CURRY LEAF PLANT INFESTED WITH MEALY BUGS
My Curry Leaf plant has been infested with powdery white growth, which appears to be causing the leaves to turn brown.
What is this growth and what is causing it? How can I get rid of it and nurse my plant back to health?
Lily Tan
The cottony white masses on the foliage of your Curry Leaf plant may indicate a mealy bug infestation.
Mealy bugs suck sap from your plant, weakening it over time as the pest population increases.
First, you can use a strong jet of water to remove as many bugs as you can. Next, spray your plant with neem or summer oil, which are environmentally friendly pesticides available for sale in local nurseries, to suffocate the pests.
Repeated applications to cover all parts of the plant are essential to keep the pest population low and avoid weakening the plant.
HAPPINESS TREE NEEDS MORE LIGHT TO THRIVE
I got this Happiness Tree about half a year ago. It has not grown much since then. Its leaves look strange and shed every week.
It gets about six hours of sunlight a day and I water thoroughly about twice a week and fertilise every few weeks. I also spray neem oil once in a while. What can be done to help it grow?
Serena Lim
The green patches on the leaves of your Happiness Tree (Garcinia subelliptica) could be lichen. Lichen consists of a fungus and algae co-existing in a symbiotic partnership and often occurs when the environment is moist and, at times, shady.
The lack of plant growth and the leave-dropping are also signs that your plant is not receiving enough light. Similar plants to yours grow well outdoors, where they are exposed to full sunlight. Try moving your plant to a brighter spot in your apartment where it can get at least six hours of direct sunlight a day.
CAMELLIA HYBRID BLOOMS IN COOLER WEATHER
I bought this plant from a market and am keeping it in a shady area of the corridor. It appears to be healthy, but it has had some flower buds for more than three months which are not blooming.
What is the name of the plant? Is it an indoor or outdoor plant, and how do I take care of it? Also, why are the buds not blooming?
Baskara Sethupathy
Your plant is a Camellia hybrid, likely containing the Camellia azalea as one of its parents. Though this hybrid may be more heat-tolerant, the flower buds that refuse to bloom could be due to the high temperatures in the lowland tropics.
You may want to move it to a spot with filtered sunlight. Deep shade is unsuitable for this plant in the long term and will lead to its decline. You may have better luck with flowers that blossom during the rainy season at the end of the year, when the nights are cooler.
FIDDLE LEAF FIG IS BOTHERED BY SPIDER MITES
My Fiddle Leaf Fig has brown spots in the middle of a few leaves.
Some other leaves are turning brown at the sides and there is also a brown dirt-like substance on the upper leaves that cannot be wiped away. What is the cause?
I keep my plant about 4m from my balcony, with no strong winds. I water it once a week and drench the pot thoroughly. The leaves did not look like that when I first bought it.
Low Shen Yi
The silvery patches on your Fiddle Leaf Fig (Ficus lyrata) indicate a spider mite infestation.
Look closely and you will see tiny red dots that move around.
Spider mites suck sap from your plant, weakening it over time as the pest population increases.
Apply a strong jet of water to remove as many pests as you can and spray your plant with neem or summer oil to suffocate the bugs.
Repeated applications to cover all parts of the plant are essential.
Your plant also seems to have a floppy light green new leaf, a result of insufficient sunlight.
This tree thrives under full sunlight outdoors and it is a misconception that it is an indoor houseplant that grows in deep shade.
Move it to a spot at home where it can be exposed to at least four to six hours of direct sunlight daily.
Hose down the plant regularly. as the process can help remove dust as well as pests.
VARIEGATION CANNOT BE EASILY INDUCED
Can my green Swiss cheese plant be turned into the variegated version?
Teresa Lau
Variegation in plants is not something ordinary gardeners can induce. The tools needed to do so are not readily available to common gardeners as the process requires either radiation or chemical mutagens.
• 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.
