Root Awakening: Guiana Chestnut can grow into a large tree

Guiana Chestnut is a popular houseplant

How should I take care of this plant? Should I repot it into a bigger pot?

Ong Bee Guat

You have a Guiana Chestnut (Pachira aquatica), a popular houseplant that is considered an auspicious plant for Chinese New Year.

It can become a large tree when grown outdoors, and thrives in parks and outdoor gardens under full sun.

By growing it in a small pot, the size of the plant can be constrained. However, you may need to water more often – the volume of its pot will be limited, as will the amount of moisture it can hold.

Also, it will need at least six hours of filtered sunlight a day when grown in an apartment setting. Under low light conditions, it will produce soft, elongated growth with widely spaced leaves.

Holy basil, mulberry are common edible plants

What are these two plants in my garden?

Gerry Ong

The first plant is a Holy Basil (Ocimum tenuiflorum). The one you are growing has green leaves, and you can also find cultivars with purple leaves in local nurseries. The plant is sacred to Hindus and used in traditional medicine. It is also used as a culinary herb in Thai cuisine.

The second plant looks like a Mulberry (Morus). There are many different cultivars, and they vary in terms of their plant size, leaf and fruit shapes and sizes, and fruiting habit.

Check for pest infestation of hibiscus

I have had these hibiscus plants for more than a year. The pink and dark red varieties rarely bloom, and their buds dry up despite the application of flowering fertilisers and previous professional gardening care. What can be done to induce flowering?

Ho Bee Hong

Different hibiscus cultivars will have different growth habits and flowering characteristics, and there may be many reasons your plant’s buds have been aborted.

First, your plant may be stressed. Avoid letting the plant dry out excessively or leaving it in waterlogged soil. Grow your plant in a well-draining growing mix.

Next, check for thrips. These are tiny insects that rasp away plant tissue when they feed.

Open up the flower buds of the affected plant and look for streaks on the petals, which are a sign of thrip infestation.

If you find that this is the case, remove all flower buds and spray plants with spinosad or filpronil, which offer effective control of thrip infestations but are available only in selected nurseries. Rotate these pesticides with other methods of pest control to reduce the likelihood of the thrips developing a resistance.

Finally, you may need to protect the developing buds from rain, as heavy rain can damage the buds and prompt the plant to abort them. Set up a clear plastic shelter that will protect plants from rain while still letting light through.

Papaya fruit is diseased

Some of my papaya fruit have these soft areas which resemble sores. What are these and what is the cause?

Victor Chan Cheng Bock

Your papaya fruit likely has a fungal disease. Infection could have taken place during the early stages of fruit development and become evident only when the fruit is physiologically mature.

Note that the disease spreads by wind and rain, and is prevalent in Singapore’s tropical climate.

Apply copper fungicide – a preventive method of plant care – regularly once fruit development has taken place. Ensure that you observe the withholding period, or the time that needs to elapse after fungicide application, so that the produce is safe for consumption. Wash the fruit thoroughly before preparation.

Remove and destroy all infected plant parts in household trash, and do not compost them. Ensure that you grow your papaya plants in a sunny and well-drained site. During fruit development and harvesting, avoid wounding the fruit.

Ensure plant is hydrated and not overfed

Why are some of the leaves of my camellia plant turning brown?

Teresa Fong

The brown patches could be caused by a number of reasons. First, ensure your plant is not allowed to dry out excessively during hot weather, as heat stress can cause the leaves to lose moisture and wilt. Leaf tissues that have dried up will die.

During the hot season, move your plant to a cooler, semi-shaded location. Mulch the soil surface and water your plant thoroughly to keep the root zone moist.

Avoid over-feeding your plant, especially with chemical fertiliser pellets. Excessive fertiliser salts can damage the plant and induce symptoms similar to those shown in the picture.