Long structures on desert rose are fruit

What are the long stems growing from this desert rose?

Adrian Ling

The two long structures growing on your desert rose (Adenium obesum) are its fruit. Cover the fruit with a bag to catch the seeds when the fruit matures and splits open. The seeds are dispersed by wind and can fly away from the parent plant if the fruit is not bagged. You can collect and sow the seeds to get new plants.

Vine could be passion fruit

What is this plant?

Thomas Tan

The plant seems to be a passion fruit vine. Passiflora edulis is the most common species grown in Singapore. Grow it in a sunny spot outdoors, as it requires space and a trellis to climb on.

Rosemary plant infested with lace bugs

The leaves of my rosemary plant seem to be affected by mites. What should I do?

Joseph Lee

The speckled markings on the leaves of your rosemary plant are likely caused by a pest called the lace bug – small black insects with lace-like wings.

Lace bugs can be difficult to eradicate with common organic pesticides, so you may need to use faster-acting chemical pesticides such as cypermethrin. Several rounds of thorough application may be required. Wear appropriate personal protection gear when spraying the pesticide.

Observe the withholding period – that is, the time that needs to elapse after spraying before you harvest the leaves for culinary purposes. Wash the leaves before using them.

Young plant could be the Fukien tea tree

This plant sprouted in one of my pots and is growing gradually. What is it?

Tay Hock Kim

The plant appears to be the Fukien tea tree (Ehretia microphylla). Larger specimens are commonly grown as bonsai. Its small red fruit are often eaten by birds, which disperse the seeds via droppings.

• 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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