Eggplant and okra have fungal disease
I grow eggplant and okra in my kitchen garden. The eggplant has fruited twice, but its leaves turned yellow and fell off. The same thing happened to the okra. Why did this happen?
Shyam Lal Verma
Your plants may have a fungal disease. Are they closely spaced and receive only several hours of sunlight daily? If this is the case, you may want to plant them farther apart in future. This promotes air circulation and aids greater sunlight exposure.
It is also important to reduce soil splashes on the lower leaves of the plants. You can apply a layer of compost to reduce the incidence of soil splashes.
For diseased plants, remove the affected leaves and discard them with household trash. Do not add them to the compost heap.
You may want to spray a fungicide such as Captan to reduce the severity of the disease.
When applying fungicides, you must observe the withholding period - the time needed to elapse before harvesting fruits from the plants for consumption.
Tip: Mapu Palm a collector's item
Often called the Mapu Palm, Licuala mattanensis is a rare fan palm that is admired for its attractive tessellated foliage.
Still very much a collector's item, the palm is a slow-growing, shade- tolerant species. Grow it in a protected, shaded portion of a tropical- themed outdoor garden.
Small young plants can be grown in pots and placed indoors, where they should get at least six hours of filtered sunlight. The plant should be protected from winds and not be allowed to dry out excessively.
The Mapu Palm likes moist, well-drained soil that is rich in organic matter. With time, plants will develop slender trunks and can grow as tall as 3m.
Spider mites infecting frangipani
The leaves of my frangipani have turned pale and are no longer glossy. New leaves are dark green and glossy, but they become pale too. The plant is in a large pot that I water completely once every two days. The pot is in the common corridor and gets the afternoon sun. There is an air-conditioner compressor near the plant so, at times, hot air blows near the leaves. What is wrong with my plant?
Your frangipani plant - its botanical name is Plumeria rubra hybrid - is likely affected by a spider mite infestation. To solve the problem, remove the affected leaves and spray the plant with neem oil or summer oil.
Your plant is in an unsuitable location that is overly dry due to its proximity to the air-conditioner compressor.
Move the plant to a more suitable spot, but bear in mind that it prefers full sun to grow well.
Mealy bugs on ficus microcarpa
My office has two pots of three layer Ficus microcarpa. Recently, I noticed white bits under their leaves. Is it an infestation? If so, how do I get rid of it?
The white spots appear to be mealy bugs. They often infest plants that are unhealthy - usually a result of unsuitable growing conditions.
The ficus prefers to grow under direct sunlight. To control the population of mealy bugs without using chemicals,use a strong jet of water to wash them off the plant regularly.
For more severe infestations, apply neem oil and summer oil on the leaves during cooler times of the day.
Orchid hybrid needs cool conditions to flower
I bought this plant during Chinese New Year. In the first few months, some flowers dropped, but new ones grew. Now, only one flower is left and there are no new buds. The leaves look healthy and continue to grow. How do I get the flowers to bloom again?
What you have is a Moth Orchid hybrid (its botanical name is Phalaenopsis hybrid).
For now, you can cut away the spent flower spikes. Also, check whether the plant is grown in the right media - imported plants are often grown in sphagnum moss. which retains too much moisture in tropical Singapore.
Most hobbyists will remove the moss and pot the plant in charcoal chips. Such hybrids generally will grow in Singapore, but may need a cooler environment to flower.
There are hobbyists who keep the orchid in air-conditioned rooms at night to promote the production of flower spikes. But the plant may flower naturally during the cooler period at the end of the year.
To promote growth and flowering, you can use a water-soluble fertiliser for orchids such as Gaviota.
• Answers by Dr Wilson Wong, a certified practising horticulturist and founder of Green Culture Singapore (www.greenculturesg.com). 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 firstname.lastname@example.org