Root Awakening: The common Alstonia tree produces scented flowers

Alstonia tree in backyard is commonly seen in Singapore

This tree in my back garden grew 7m to 8m tall in two years. What is it? Are there such trees in Singapore and is it an invasive species?

Victor Liu

The tree looks like an Alstonia and is not considered an invasive plant here. A closer examination is required to ascertain the exact species.

Pulai Penipu Paya (Alstonia angustifolia) and Indian Pulai (Alstonia scholaris) are two common species of the genus that are planted in local landscapes. They are grown for their tiered appearance and scented flowers.

Your Alstonia could have grown from one of these trees’ seeds, which are very light and dispersed by wind.

Fiddle-leaf fig may have been burnt by pesticide or fertiliser

I have had my plant for more than two years, but it has hardly grown in height. In recent weeks, its leaves have developed brown patches. I keep it indoors, monitor the soil wetness and spray a combination of organic pesticides and nutrients once or twice a week. What is wrong with my plant?

Winnie Goh Woei Jing

If your plant is placed indoors, it may be suffering from a lack of sunlight. This plant needs at least six hours a day of direct sunlight for optimal growth.

Did the burn marks appear after the application of pesticide and fertiliser? Always test these on a small part of the plant before spraying on the rest of it. You may need to dilute the product, so the leaves will not be affected.

A sun-loving plant grown under low light will be weaker and prone to disease and pest attacks.

Oxalis propagated via division

How can I propagate the oxalis plant? I like to eat the flowers, as they taste sweet and sour.

Adrian Ling

Your plant is the Variegated Purple Oxalis (Oxalis regnellii, cultivar name Atropurpurea) and it takes on a clumping habit as it grows. You can divide the plant to propagate it.

Lady’s finger plant needs a large root space

I planted lady’s finger plants from seeds. The seeds were collected from dried pods and refrigerated for a few months. They sprouted into young plants and were transplanted into the ground when they were about 12cm tall.

The plant has flowered and fruited despite being so small. How can I encourage a normal growth habit?

Alex Quek

The lady’s finger plant produces flowers and fruit within a fixed time frame after seed germination. In commercial farms, seedlings are moved outdoors and fed with appropriate nutrients for robust growth.

Give your lady’s finger plant at least six hours a day of direct sunlight, preferably outdoors in the ground.

Alternatively, a single plant needs a large pot of at least 60cm in depth and diameter for sufficient root space. Do not crowd it in a small space or delay transplantation. Feed plants regularly and at fixed intervals.

Any delay in transplantation or providing sunlight and fertiliser – as well as limited root space – will result in stunted plants that will produce small fruit prematurely.

Elephant ear plant has fungal disease

My plant is grown in a pot on my balcony with plenty of sunlight and is regularly watered and fertilised. The leaves are turning brown and crinkled at the edges. What is wrong?

Anand Danani

It looks as though the leaves of your elephant ear plant are infected with a fungal disease. Leaves can become infected by disease-causing organisms in the environment when they infiltrate plant tissues.

Avoid handling the plant and protect it from getting injured by elements such as strong winds.

This plant consumes a lot of water, so ensure your pot is large enough to accommodate sufficient moisture-retaining and well-draining potting mix that is rich in organic matter.

A larger pot can retain more soil and thus more moisture for the plant, whereas a small pot will fill quickly with roots and restrict the plant’s growth over time.

The leaf edges of your plant are chlorotic. Chlorosis is a yellowing of normally green leaves due to a lack of chlorophyll.

Do check that the soil is not too acidic or alkaline, as this can restrict the take-up of nutrients even when the plant has been fertilised. Provide the plant with some shade during hot and dry weather.