Jambu fruit may have been damaged by pests or chemical sprays

My jambu tree used to produce smooth, sweet fruit. But the last few batches have had very rough skin. What is wrong? Is the fruit still edible?

Seah Soon Huat

The rough skin could be caused by a number of reasons. Sucking pests such as mites could have fed on the developing fruit, leaving marks on the skin.

Use a magnifying glass to inspect any damaged fruit for evidence of these pests and apply summer oil on your plant to manage the pest population.

Another factor could be chemical damage. Did you spray water-soluble fertilisers or pesticides on your plant? Such substances, when applied in too high a concentration or during hot weather, can damage the surfaces of plants. Apply these substances only during cooler weather and use a smaller dose to reduce the likelihood of damage.

If the damage is caused by mites, it is mostly cosmetic and the fruit can be peeled and consumed. If it is due to chemical application, you may have to discard damaged fruit.

Ensure your plant is growing under optimal conditions, and is not stressed by a lack of water and other environmental factors.

Begonia needs more light

My Begonia Rex plants do not survive beyond a few months. They get bright indirect sunlight and I water when the surface of the soil is dry to the touch. I also have not succeeded in multiplying them via leaf propagation.

Vinata Goswamy

Most foliage begonia are shade-loving plants, but still need sunlight to thrive. Give it four hours of filtered sunlight a day or keep it under artificial LED grow lights for eight to 12 hours.

Many hobbyists struggle to grow plants like yours due to the nature of the moisture-retentive organic growing mix that nursery plants are kept in. This can lead to root rot if there is not enough light and the moisture does not evaporate fast enough. Begonia do not like wet feet and may fare better in a porous, well-draining mix.

You may want to repot your begonia by carefully removing some of the original mix and planting it in a more suitable growing mix. Avoid burying the creeping rhizomes and water the plant when the soil is slightly dry, but do not let it dry out completely.

Foliage begonia can be propagated via leaf wedges or by cutting slits in whole leaves. Some species are easier to propagate than others. It is essential to keep the cuttings in a porous yet moist propagation medium such as sphagnum moss.

Brown leaf edges are due to dryness or excessive fertiliser

My ginger flower plant gets indirect sunlight all day, is watered every few days and fertilised monthly. The leaf tips are brown and dry, and some leaves seem to have been torn or eaten. I spray neem oil twice a week to deter pests. Why are the leaves browning and how can I encourage the plant to flower? Also, how much water does my plant need?

Anand Danani

The brown leaf edges could be due to excessive salt content in the root zone. This can occur if a plant has been grown in the same pot for a long time and had regular applications of chemical fertiliser.

This issue can be tricky to remedy. You may want to replace some of the growing mix with a fresh mix rich in organic matter. Cut back on chemical fertiliser application. You can also consider using organic fertiliser like goat manure pellets and seaweed extract.

Ensure the growing area is not too windy, as this can dry your plant out and damage the leaves. Consider growing it in a spot with more protection from the elements.

As for pest attacks, neem oil generally works by suffocating small sap-sucking pests, but chewing insects can be more difficult to manage. You may have to remove these by hand.

Give your plant at least six hours a day of filtered sunlight. A plant grown in deep shade will not flower often. Water it enough to keep the soil moist, but do not let it get waterlogged or dry out completely.

Repot young orchid plant

My orchid plant has a new offshoot attached to the last flower remaining on the stalk. The other petals at the base have wilted. How can I save this plant? Do I need to repot the new offshoot?

Angela Chee

Check if the baby plant has roots, as this will increase its odds of survival when transplanted.

Fill a small flower pot with some fine charcoal chips measuring between 1cm to 3cm in diameter.

Carefully remove the baby plant from the branch and place it in the pot. Bury the roots with more charcoal chips, filling only to the point between the baby plant’s roots and the base of the leaves.

Do not bury the plant too deeply or compact the chips down. If the plant is not stable, insert chopsticks around it to provide support.

Water the chips thoroughly and place the pot in a location that gets filtered sunlight for about four to six hours daily. Water regularly thereafter, but do so only when the roots dry out. Apply a water-soluble orchid fertiliser as needed, following instructions on the packaging.