Alocasia needs well-draining, aerated mix

I bought this plant some three weeks ago. It had strong and healthy leaves at the time. I watered it every three days or so, but the leaves turned yellow. It is kept in the shade in a spot that is not too windy. How can I restore my plant’s vibrant green leaves?

Catherine Ng

Your plant is commonly known as the African Mask (Alocasia x amazonica).

The reason for its yellow leaves could be a wet root zone. Three days after watering, stick your finger beneath the growing media and feel for moisture. If it is moist, let the growing media dry out for a few more days before watering. But do not wait until the plant wilts to water it.

This plant is sensitive to wet feet and will rot if the growing media is perpetually wet. A proper watering routine will depend on factors such as its environment, the size of the pot and plant, and the type of growing media.

Most gardeners repot this plant into a gritty mix of pine bark, pumice and coconut husk chunks. This is very much like an epiphyte mix that is open and aerated. After watering, it dries out quickly.

If you live in an apartment, make sure this plant is in a spot that gets at least four hours a day of filtered sunlight. Do not keep it in deep shade, as there will not be enough light for the plant to carry out photosynthesis.

Also, ensure that you do not bury this plant too deeply. The crown of the plant will rot if it is covered.

Young tomato plant growing in pot may be from compost

What plant is growing in my garden?

Priscillia Chong

The plant in the blue pot is a tomato plant. Did you throw some seeds into the soil or use compost that contained tomato seeds and pulp? This plant could have grown from those.

The tomato plant will require a much larger pot if you are growing it to maturity. Depending on the variety, the vining types will require a trellis or support to grow on. They require at least six hours of direct sunlight to thrive and a moist but well-draining growing mix. Hand pollination may be required if natural pollinators are absent.

Lanky Moringa due to lack of light

Are my plants Moringa? The taller one has grown well, but has smaller leaves than the shorter ones.

Isaac Ong

Your plants are Moringa (Moringa oleifera). Their lanky appearance indicates a lack of light. In an apartment setting, place the pot in an area that gets at least four hours a day of direct sunlight. With time, the plant will need a bigger pot.

Some variants of Black Nightshade are toxic

Can you identify this plant in my garden?

Roslin Chua

You have a Black Nightshade (Solanum nigrum). There are several species that look very similar, so exercise caution as some variants are toxic and unfit for human consumption.

While the leaves and fruit of this plant can be cooked, discard and replace the cooking water several times during the process to remove any toxins.

Desert Rose needs six hours of sunlight to flower

What is this plant and why does it not flower frequently?

Kenneth Tham

The plant is the Desert Rose (Adenium cultivar). It has likely been grown from a seed, due to the prominent caudex found at the base of the plant. Grow it in a sunny spot that gets at least six hours a day of direct sunlight, as shade will discourage flower production.

To encourage the plant to flower, you can try feeding it a flowering fertiliser. The frequency of flowering will also depend on the cultivar you are growing. Different cultivars can exhibit different flowering habits even under the same conditions.

• Answers by Dr Wilson Wong, an NParks-certified practising horticulturist and parks manager. He is the founder of Green Culture Singapore and an adjunct assistant professor (Food Science & Technology) at the National University of Singapore.
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