Disease can result from rough handling of plant
I have a few pots of money plant. As the plants are overcrowded, I re-potted them into bigger pots with new soil bought from a nursery. I noticed that the plants have stopped thriving like they used to. Also, the stems of the plants are turning darker in colour (photo 1). New leaves that grew quickly turned black and have curled up (photo 2). What is wrong?
T.H. Chan
The new leaves of your money plant (Epipremnum aureum) may be infected by a fungus or bacteria.
A fungal infection is generally characterised by a dry brown rot while one that is caused by a bacteria will be mushy and, at times, smelly. Such infestations can come about due to rough handling and damaged tissue is then infected by bacteria or fungus. You may want to prune damaged parts to prevent its spread.
More importantly, move the plant to a brighter spot with some air circulation. An overly shady and moist location can lead to fungal and bacterial diseases in the plant.
In one of your pictures, there seems to be a scale insect infestation on your plant. Scale insects appear as small, brown spots or specks which can be scraped off.
To manage the pest population, use a soft toothbrush to remove the scale insects. Neem oil and summer oil can also be sprayed on the plant - the oil suffocates and kills the pests.
Often, the lack of light will lead to an unhealthy plant that is prone to pests and diseases. Try and improve the growing conditions so that your plants can thrive.
Tutsan is often used in floristry
I bought this berry-like plant and left it in a vase. Instead of a decline, the plant has shown remarkable resilience. Its stalk ends have new strong roots and are still growing. Green leaves are growing and the berries are darkening, only to bloom into small yellow flowers. What is its name and how can I grow it properly? Currently, it gets plenty of sun on the balcony.
Aileen Han
The picture shows cuttings of Hypericum androsaemum, commonly known as Tutsan. It is often used as a cut-flower material in floristry.
It can be found in western Europe, southern Europe, North Africa and Iran. Due to the differences in climate, it can suffer from root rot and foliar fungal diseases in Singapore's hot and humid climate outdoors.
You may want to grow the plant in a sunny spot in your garden and in a pot with well-drained soil. This may help to mitigate some of the issues it may face in tropical Singapore.
It will be interesting to find out if you manage to grow it successfully in Singapore and if it flowers and fruits.
Blooms needed to confirm plant is Chinese Violet
My friend gave me this when it was a young sapling. I was told it was a herb I can cook with luo han guo to make a cooling drink, but she could not tell what the plant was. It has since flourished. What plant is this and can it be eaten instead of just being used to make tea?
Caroline Low
Looking at the leaves, it appears that your plant may be Asystasia gangetica, commonly known as the Chinese Violet. A more definitive identification can be done if its flowers can be seen.
The young shoots and tender leaves of the Chinese Violet are reported to be harvested and eaten as a vegetable.
However, for safety reasons, it is recommended to use parts of a plant for food or medicinal uses only after its identity is known.
Euphorbia pachypodioides an ornamental plant
What is this plant and does it need to be re-potted? It grows well and quickly in cooler weather conditions.
Fong Weng Khin
The plant is botanically known as Euphorbia pachypodioides.
It is a drought-tolerant, highly ornamental species with a swollen stem and blue-green leaves that have purple undersides.
It can be grown under filtered sunlight for at least four hours a day and needs a gritty, well-drained media.
You can check the condition of its roots. If they have filled the pot, you can try to move the plant into a slightly larger container. Avoid moving it into an overly large pot as the excess growing media may not dry out fast enough, leading to rotting of the plant.
Air plant needs more light
How should I care for my air plant? It has not flowered for a long time. It is parched even though I water it regularly. My balcony is very windy and does not have direct sunlight.
Phua Siew Hoon
It appears that the air plant is lacking in sunlight that is required for healthy and compact growth. Its leaves are long and thin compared with what is expected of a plant that is given more light.
Move the plant to a place where it can receive at least four hours of filtered sunlight daily.
It can be grown among other shrubby plants which will transpire and provide higher ambient humidity for it. It may also grow better with some protection from surrounding plants from drying winds.
• 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 stlife@sph.com.sg
