Pandan leaves discoloured due to spider mites

I am trying to grow pandan from small offshoots with roots. It has been about two months and new leaves are growing from the centre. However, the outer leaves are discoloured or yellow. They get indirect afternoon sun and are in a self-watering pot with additional drip irrigation in the morning and evening. What is the problem and what can I do?

Margaret Lee

Your pandan plant appears to be infested with spider mites, which are sap-sucking pests that appear as small dots below the damaged leaves. You will need to spray summer oil, a pesticide that will suffocate the pests. Thorough coverage and repeated sprays are required to eradicate the pests. You can also spray your plants with water regularly to help wash the pests off your plant.

Ensure your plant is grown in a location with at least four hours of direct sunlight in an apartment setting. Avoid growing your plant in a windy site and ensure the root zone is moist. Do not allow your plant to dry out.

Butternut squash plant may be diseased

We planted a few butternut squash plants. All are doing okay, except for this plant, which seems to be dying. What could possibly have caused it? All the plants have the same nutrient levels and growing media.

Adrian Ling

The wilted plant could be suffering from a bacterial or fungal infection. There is little you can do once the plant has shown symptoms. The infected plant will exhibit an unhealthy root system, featuring decay and discolouration. The interior of the stem may also show discolouration of the vascular system.

You will need to disinfect the growing system to prevent future infection of new plants. Avoid letting plants sit in water for prolonged periods and control chewing pests. Do sterilise cutting tools in between the pruning of separate plants.

Yellow Bells plant detests waterlogging

My gardeners planted my Yellow Bells tree in February 2025. I have been watering it regularly in the late afternoon. It gets full sun all day. Over the last few days, I’ve noticed that the leaves are starting to look shrivelled. I also noticed some ants on its branches. Is the tree being attacked by pests? What can I do to save it? I lost an Orange Bells in a similar manner, so I’d appreciate any help to save my Yellow Bells.

Lim Tsu Yee

The Yellow Bells (Tecoma stans) is a large flowering shrub that needs a sunny site and well-draining soil to thrive. Avoid growing it in soil that is claylike or compacted, as such conditions will cause the roots to remain wet for prolonged periods. Waterlogged conditions will cause the roots to become diseased, rot and die, and the plant will wilt as water cannot be transported to the leaves.

Check other locations in the garden to see if there is a more suitable spot for this plant species. Alternatively, you can grow it in a large planter box or container.

Coleus plants require direct sunlight to grow well

I recently purchased two plants and they are growing well. However, I noticed the pots are now too small. If I want to repot them, what type of soil is the most suitable?

I have also found a wild plant in one of my pots. What plant is that? Is it a flowering plant?

Pamelin Ho

The plants with colourful leaves are commonly called Coleus and their botanical name is Coleus scutellarioides.

In general, they require at least six hours of direct sunlight to thrive. Well-draining but moisture-retentive soil is preferred. You will need to remove flowers as soon as they appear to ensure the plants remain compact and attractive.

The plant with green leaves in the other pot is a common weed in Singapore called Monkey Potato. Its botanical name is Plectranthus monostachyus and it is in the same plant family as the Coleus. This plant does not produce attractive flowers.

Lemon tree infested with mites

Over the past few weeks, I have noticed white patches appearing on the leaves of my lemon tree. Any advice you can offer on identifying the cause and a treatment plan would be greatly appreciated.

Freddy Tan

Your lemon tree has likely been infested with mites, which are tiny sap-sucking pests. You can spray summer oil on the plant; thorough coverage is needed to suffocate the pests. Repeated thorough applications are required to manage the pest population and keep plant damage to a minimum. For a start, apply summer oil weekly.