Too little sunlight, too much wind for basil
I bought this basil plant two months ago. It is shedding leaves and showing signs of rot. How do I save it?
It appears that the plant is suffering from a lack of sufficient sunlight. It should be exposed to at least four hours of direct sunlight daily to ensure robust growth.
The dry leaves could be due to the lack of water or an overly windy location. Constant winds can lead to premature drying of leaves. Basil should preferably be grown in a protected location.
It also appears that the plant's roots have filled the pot. You may want to move it to a larger pot with fresh growing media. When a plant is pot bound like this, there is very little soil to hold water for use by the plant. When water is lacking, plants will drop their lower leaves.
In the meantime, you may want to propagate new plants by taking tip cuttings and rooting them in water. When new roots form, you can transfer them to a new pot.
Tip: Get festive with Euphorbia francoisii
The Christmas Poinsettia (Euphorbia pulcherrima), a shrub-like festive plant native to Central America, is often displayed during the Christmas season. There is another Euphorbia species, Euphorbia francoisii, native to the arid regions of Madagascar, that you can grow.
Much breeding work has been done recently and many cultivars with attractive leaves are now available. Akin to the common nerve plant (Fittonia), the leaves come in attractive patterns. They make ideal house plants as they are drought-tolerant and can be grown near a bright area.
Plants develop a swollen caudex and many branches. Buy them from hobbyists at places such as HortPark's Garden Bazaar.
Tetracera is a traditional fish poison in India
This climber grew wildly under my tree. The reddish-brown stalk is rough and clings onto my plants. Is this plant poisonous? Does it flower?
The vine appears to be a species of Tetracera, a native plant. In local landscapes, the most common species is Tetracera indica.
The plant's common name is Akar Mempelas and it produces bunches of white flowers. You may prune the plant to manage its growth.
Not much information is available on the toxicity of the plant, although it is traditionally used as fish poison in India.
It is also a medicinal plant used to treat itches, snake bites and symptoms of the common cold.
Its rough-textured leaves are used as sandpaper while its tough stems are made into ropes.
Lady of the Night is poisonous
What is this flower?
This shrub is botanically known as Brunfelsia americana. Its common name is Lady of the Night and it belongs to the tomato family (Solanaceae). Note that it is poisonous.
Its newly opened flowers are white and turn yellow as they age. At night, its flowers are more fragrant.
The plant has another relative that is commonly grown in Singapore. It is known as Yesterday- Today-and-Tomorrow, although its botanical name is Brunfelsia pauciflora.
It has fragrant flowers that undergo a colour change with age - from purple to lighter blue and finally white before they fade.
Move 10-year-old plant to new pot
My plant has been infested with mealy bugs and the soil with ants. I have had the plant for about 10 years. Could its age be the cause of these problems and should I transplant it to another pot?
Since the soil is compacted and the plant has probably been growing in it for a long time, consider moving the plant to some fresh media with organic matter. This will help keep the soil more friable and aerated.
Incorporate mature compost into the soil occasionally to reduce the likelihood of soil compaction. During transplanting, remove some of the old soil media, unwind entangled roots and cut away black, rotten and dead roots.
Depending on the plant, some can be very sensitive to root disturbance. Care should be taken not to remove too much of the old soil media which will damage the roots.
Before you move the plant, treat the roots to kill off soil mealy bugs. There is no effective organic or environmentally friendly solution to treat soil mealy bugs. The root ball should be soaked in a pesticide solution such as cypermethrin or dimethoate. Handle these chemical pesticides with care.
Also, spray the same pesticide solution on the aerial parts of the plant.
•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.
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