Desert rose needs well-draining soil

I was told this plant is Adenium obesum and to water it once or twice a week. The leaves seem to wither easily and no flowers are blooming. It is placed in a west-facing location under indirect sunlight. How do I get my plant to bloom?

Kathleen Ong

Your desert rose looks lanky. From your description, it is not being grown under the right conditions. It must get at least six hours of direct sunlight a day in order to thrive.

As this plant is sensitive to wet feet, grow it in well-draining soil so the root zone does not remain soggy for a prolonged period. Feeding it with a flowering fertiliser is encouraged.

Hoya needs light, fertiliser

I bought this Hoya plant 10 years ago and placed it in the corridor. It bloomed for four years, but then stopped. How do I get it to bloom again?

Aye Kywe

To flower, this plant needs at least four hours of filtered sunlight a day. Feed it regularly with a water-soluble flowering fertiliser for orchids. You can spray the entire plant with dilute fertiliser solution as well.

Avoid cutting the peduncle – the old flower stalk produced by the plant – on the stem, as new flowers emerge from this structure.

Have you changed the plant’s growing location over the years? It may have flourished in the past due to having more light than it does now.

Also, try to unwind the vines without breaking the stems, and train them to grow on a larger structure. Its current coiled state is not optimal as the leaves are shading one another.

Diseased Gardenia buds common during wet weather

I have a Gardenia plant in the ground. It gets afternoon sun and has produced, but aborted, many flower buds due to rot at the base. What is wrong? Also, I see tiny brown insects on the plant. What are these and how do I get rid of them? Pesticide did not work.

Lim Seh Wah

Without a picture, the brown pests cannot be reliably identified. As the Gardenia is a woody perennial plant, scale insects are a common occurrence. You may want to check if your plant has been infested by this pest.

Does the flower bud issue occur only during the rainy season? Heavy rain can damage flower buds and disease-causing organisms will then enter the wounds. Moist conditions during the rainy season can also be conducive for disease to spread. Fungicides may alleviate the severity of fungal disease.

A more effective solution is to erect a rain shelter to protect your plants. Also, avoid wetting the buds and opened flowers when you water your plants.

Plant is a weed

What is this plant I found in Malaysia? It has a hollow-looking fruit with a hard milky seed in the centre. Is it edible?

Winston Lee

This plant is known as Wild Gooseberry or Physalis minima. It is a relative of the Cape Gooseberry, which produces larger fruit that are commonly used to adorn cakes.

The fruit of this species are edible when the outer papery covering turns dry and brown. The fruit inside should be bright orange for optimal taste. The plant often occurs as a wasteland weed in this part of the world.

Portulaca molokiniensis needs well-draining mix

My plant’s leaves have turned white and some of the tips are black. What is the cause and how do I treat it?

Adrian Ling

Did you get a chemically treated Portulaca molokiniensis that has been artificially induced to produce white leaves? These leaves will burn easily under sunny conditions.

After a period of time, new leaves that emerge will be green, and the plant will then need to be placed in a location that gets about six hours of direct sunlight to keep it healthy and compact. A lack of light often causes this plant to decline.

Your plant seems to be grown in a self-watering pot. Succulents such as this species generally do not like wet root zones, so let the roots dry out between watering sessions to prevent root rot.

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