Root Awakening: Caesalpinia ferrea does not tolerate wet feet

Check soil conditions of growing site

What is wrong with my Caesalpinia ferrea? One is growing well and the other is bald with very few leaves. Its leaves all fall off after a short time. I water and fertilise both plants the same way.

Julia Lee

This tree species does not tolerate wet feet. In urban environments, many growing sites have poor drainage due to compacted soil. Check the condition of the soil to determine the exact nature of the problem.

The tree is also too close to the wall. Trees need space to develop a healthy root system.

Desert rose may be infested with pests

The petals on this desert rose turn brown even before blooming. What is wrong?

Tina Lee

Ensure that your flowers and developing buds are not damaged by rain. Rain damage can leave plants prone to infection by pathogenic organisms such as fungi or bacteria. Protect your plants with a clear shelter during the wet season and spray them with fungicides to prevent fungal infection.

Another possibility is that your plant is infested with thrips, which scrape and eat floral tissue. They are small and not easily spotted with the naked eye. Thrip damage manifests as brown patches.

Thrip infestations are extremely difficult to treat. Spray pesticides such as abamectin or spinosad regularly during floral development to mitigate the damage.

Propagate Happiness Tree from seeds

How do I propagate this plant?

Gary Tim

The plant is the Happiness Tree (Garcinia subelliptica) and is often grown in local landscapes. It is a slow-growing tree and is propagated from seeds. Although its seeds are not commonly sold here, you can buy its saplings at large nurseries.

Summer Snapdragon needs sun; Dendrobium hybrid may be diseased

I bought this lavender plant just before Chinese New Year, but it withered in only a few weeks. It is in a spot on my balcony with no direct sunlight. How can I help my plant recover and bloom?

I also have an orchid. What species is this and how do I maintain it? It is watered weekly. Also, why are there black spots on some of the leaves? The affected leaves do not grow back after pruning.

Ling Kok Yong

The first plant is not lavender but Summer Snapdragon (Angelonia angustifolia). The issues you mention are likely due to a lack of light. This is a sun-loving plant and needs six hours of direct sunlight a day to stay compact and floriferous. It also needs to be grown in a moist substrate and should not be allowed to dry out.

A lack of light will cause this plant to stretch and become more prone to disease. Also, it will not produce flowers. Healthy Summer Snapdragons in ideal growing conditions will benefit from having their flowering stems pruned to make way for new growth.

The second plant, the orchid, is likely a miniature Dendrobium hybrid. These need four to six hours of filtered sunlight daily to grow well. As with the Summer Snapdragon, a lack of light will lead to stretched growth, a low flowering rate and an increased likelihood of disease.

The black spots may have been caused by either pathogenic fungi or bacteria. You can apply fungicides, which are available at local nurseries, to suppress or reduce the severity of any fungal disease. Make sure the plant has enough light and air circulation.

Finally, use a water-soluble orchid fertiliser. These fertilisers can be dissolved in water to create a solution that will provide the plant with nutrients and help it grow. This orchid grows by producing new pseudo-stems that rise from the base of the plant. Leaves pruned from the existing ones will not regenerate.