Perfume Tree lacks sufficient light
I bought this plant a month ago and placed it in a shady corridor, where it gets indirect sunlight. I water it twice a week. Two weeks ago, the leaves started dropping. Some branches have also shrivelled up. What can I do to save it?
The botanical name of the plant is Fagraea ceilanica. It is also known as "Perfume Tree".
As its name suggests, its trumpet-shaped flowers are strongly scented. It is normally sold as a shrub, though it can grow into a tree if grown in the ground.
This imported version you have looks somewhat different from the Singapore native, which has larger and broader leaves. It appears to be less floriferous too. Local nurseries sometimes sell a variegated version, where the green leaves have splashes of yellow.
Your plant is probably not getting enough light. It should get at least six hours of direct sunlight daily.
Move it to a sunny spot in your home to allow it to recuperate and grow it in moisture-retentive and well-drained soil.
Desert rose infested by spider mites
The leaves of my desert rose look sickly. What is wrong with the plant? It is grown in my garden, where it gets about four to five hours of sunshine daily, and in mixed media that is mostly burnt soil.
Your desert rose (Adenium obesum hybrid) may be affected by sucking pests such as spider mites. Examine the underside of the leaves closely to see if there are small, red dots, which are spider mites. In very severe infestations, you may see a fine web being spun.
First, remove the infested leaves and then spray the plant with either neem oil or summer oil which suffocates the pests. Repeat applications are usually needed to reduce the pest population.
Always follow the instructions when making the pesticide solution and spray the plant in the evening when it is cooler so that the leaves do not get burnt.
Let lavender dry out a little before watering
What is this plant and can it be eaten?
The potted plant is a cultivar of lavender and is likely to be Lavandula x ginginsii "Goodwin Creek Gray". It goes by the name Goodwin Creek Gray Lavender.
Many of these herbs are imported and are grown in a coconut peat-based substrate that retains too much water.
Lavenders are very sensitive to high ambient humidity and excessive moisture in the root zone. They decline easily from root or crown rot that starts from the base of the plant.
I recommend cutting its tips and rooting them in coarse gravel sand. When these cuttings have rooted, transfer them to a pot containing a coarse, well- draining substrate with pumice and fine, expanded clay pellets. This porous mix will keep the plant's roots well-drained and aerated.
Water the plant judiciously and allow it to dry out a little before watering again. Lavenders need to be grown under direct sunlight for four to six hours daily. Shelter the plant when it rains.
You can boil the leaves and make a tea.
Direct sunlight for healthier Garden croton
What is the name of this plant and how do I propagate it? It used to be outdoors, but I have moved it indoors where it grows well under indirect sunlight.
The plant is a cultivar of the Garden croton or Variegated croton. Its botanical name is Codiaeum "Mother and Daughter".
Its unusual name comes from how it looks. Each of the long, narrow leaves has a small leaflet that dangles off its tip, which resembles a mother holding her daughter's hand.
Garden crotons, in general, do better when exposed to direct sunlight. When grown under optimal light conditions, they tend to be healthier, feature more vivid foliage colours and are less prone to being attacked by pests.
The plant also needs to be grown in well-drained soil as too much water can lead to root rot.
It is poisonous. Do not eat it and avoid touching the milky sap.
Indian spurge tree has poisonous sap
Is this the Crown of Thorns? When I bought it a few weeks ago, its thick green stem had a few buds, which have since dried and dropped. The plant gets the afternoon sun. How long will it take to flower?
It is not the Crown of Thorns. This succulent plant is botanically known as Euphorbia neriifolia. Its common name is the Indian spurge tree and, like many of its relatives, it exudes a poisonous white sap when injured.
Unlike the Crown of Thorns (Euphorbia milii and its hybrids), the flowers of the Indian spurge tree are small and not conspicuous.
Do not touch the sap or eat any part of the plant. It grows well when it gets at least six hours of direct sunlight and has well-drained soil.
•Answers by Dr Wilson Wong, a certified practising horticulturist and founder of Green Culture Singapore (www.green culturesg.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 firstname.lastname@example.org