Ruellia may have been attacked by mites
I planted a few Ruellia simplex, both tall- and short-stem varieties, in January in a rectangular pot. The plants are fertilised every two weeks and get about four hours of sun daily. They produced purple flowers every day. About a month ago, I saw patches of brown and light green on top of the leaves, as well as three round insects. I have difficulty scrubbing the patches off the leaves. What is happening to the plants?
The culprit could be eriophyoid mites and these may be controlled by spraying the plants with lime sulphur or summer oil.
Spray immediately and cover all parts of the plant during the cooler part of the day. Repeated applications with rotation between the two pesticides may be needed to provide adequate control to reduce the extent of damage to your plants’ leaves.
Grow ficus in a large pot to contain its growth
I last wrote to you about the difficulties with my indoor tree (identified as Ficus benghalensis), with its leaves browning and being eaten by bugs. I am planning to transplant it to a side garden at a house. However, the land is bordered by a retaining wall-cum-fence. I am worried the root system of the tree may spread too wide and damage the existing drain and the wall. Is it safe to transplant the tree, along with a variegated species on this side garden?
Cheng Liang Gek
You are correct that planting your ficus plant in the ground, where it will grow large with its invasive roots, can damage nearby structures. There is no perfect solution to this. Root control growing bags may not work as the fabric used to make them will deteriorate over time.
You may want to consider growing the plant in a large container and place a concrete slab below the base of the pot. The concrete slab is a way to prevent the roots of the plant from growing directly into the ground, especially if the container is placed over earth. You will need to monitor the growth of the roots on a regular basis to prevent them from doing so.
As the plant grows, you will need to prune its canopy to manage its size so that it does not topple over from its own weight or get blown over by the wind. You may need to construct a supporting structure to hold the plant and its container in place as an added measure.
Note that a smaller plant will be easier to maintain, especially compared with the expense and equipment required for the upkeep of a larger plant.
Fig plant requires sunlight to thrive
I have a fig plant, which I repotted. I pruned the old leaves, leaving a single leaf. I noticed that it was not growing well, as there are no new leaves growing from the plant. There were also some ants found on the leaf. What should I do?
Is the location where the picture was taken the actual spot that the edible fig plant (botanical name: Ficus carica) is being grown? Note that the parapet casts shade on the plant.
The edible fig plant benefits from getting at least six hours of direct sunlight daily. The lack of sunlight will lead to poor plant health and growth. Hence you may want to install a plant rack just below the parapet and place the plant on it. The elevated position will expose the plant to more light.
Also, grow your plant in well-drained growing media. The edible fig does not do well with a waterlogged root zone.
After transplanting your plant, depending on the amount of root disturbance, the plant may take some time to put out new roots before it grows above the soil.
As for the ants, do check for any infestations of sap-sucking pests such as aphid or scale insects, as they secrete sweet liquid which attracts ants.
Shrub is the Cekur Manis
I am not sure where this plant came from, but it grows very fast in my garden. Is it poisonous or edible?
The plant is the Cekur Manis (botanical name: Sauropus androgynus). It is also known via a number of common names such as Star Gooseberry, Katuk and Sweet Leaf.
This plant is native to Singapore. The red structures are the flowers of the plant which are followed by light green fruit. Note that the leaves of the plants are edible and the fruit is not normally consumed.
The leaves of this plant should be consumed only after being cooked thoroughly. Consuming them raw can lead to a permanent lung disease known as bronchiolitis obliterans, where the small airways in the lungs (bronchioles) are blocked by inflamed scar tissue. Do seek professional medical attention if you have consumed raw Cekur Manis and feel unwell.
Ceylon spinach is an edible leafy vegetable
I have this plant in my garden. What is its name and is it edible? How do I care for it?
The plant is botanically known as Basella alba. Its common names include Malabar spinach and Ceylon spinach, and the young shoots sold in local markets are called “di huang miao”, which translates to “Emperor shoots”. There is another variant with red stems.
This plant grows as a vine and requires a structure to climb on. It grows best under direct sunlight to reduce the likelihood of fungal disease on its leaves. It can be adapted to grow under filtered sunlight. The soil should be moist, fertile and well-drained.
- Answers by Dr Wilson Wong, an NParks-certified practising horticulturist, parks manager and ISA-certified arborist. He is the founder of Green Culture Singapore and an adjunct assistant professor (Food Science & Technology) at the National University of Singapore.
- 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. We reserve the right to edit and reject questions.