Root Awakening: Jujube may be infested with fruit fly larvae

Bag fruit to prevent pests

My jujube plant bears many fruit, but almost all rot before ripening. What is wrong?

Chew Eng Goh

The small brown dots seen on the fruit are likely puncture marks in which fruit flies have laid their eggs. This can damage fruit and cause them to be aborted prematurely.

Bag the fruit up to prevent fruit flies from laying eggs on developing fruit. This needs to be done early, ideally once the young fruit start to form.

You can also build or buy a fruit fly trap and hang it near your plants. Such traps have a pheromone lure that attracts and drowns fruit flies in a reservoir of water at each trap’s base.

Springtails are harmless

There are tiny white bugs in the soil of my plants. They crawl quickly and do not jump. When I found the bugs, most of the plants were wilted, stunted and had yellowing leaves. Some plants’ roots also seemed to have white mould.

Are these aphids, springtails or soil mites? I have treated the soil with neem oil and pyrethrin, but the bugs come back quickly.

Christine Wong

The white creatures are likely springtails. They are commonly seen in moist potting media rich in organic matter.

Springtails are part of the nutrient cycling process, as they feed on organic matter and break it down. They are generally harmless to large plants. Their population should reduce when the organic matter in the soil has completely broken down or when the growing mix is left to dry.

The mould-like substance cannot be identified without a picture. In a growing mix made up of undecomposed organic matter, it is common to see mould, as it is a part of the nutrient cycling process. It will disappear if the media dries out or organic matter breaks down.

Check if the substance contains small pests such as mealy bugs, which suck sap from roots and affect their growth. They are common in soil-less potting media and can be difficult to control. Chemical pesticide drenches are often needed to manage infestations.

Remove caterpillars by hand or use Dipel

My plants have been attacked by pests. How do I get rid of them?

Lee Chee Chee

Your Lady’s Finger plants have been attacked by caterpillars. If there are only a few pests, use tongs or chopsticks to remove them.

Otherwise, spray your plant with a pesticide called Dipel, which is available for sale at local nurseries. It works best on young caterpillars and can be sprayed on the leaves as a preventative measure.

Plant needs healthy roots before leaves can grow

I cut off the branches of my Desert Rose after it was infested with spider mites, and let it dry out before repotting about two months ago. How can I get it to regrow its leaves?

Lee Sook Cheng

Your plant needs to produce new roots and establish itself before it puts forth new growth.

At this time, manage your plant’s watering regimen carefully. A wet root zone can cause the plant to rot, as the lack of leaves will limit water intake.

In the meantime, place your plant in a bright spot with good air circulation. Move it to a sunnier location once you see new leaves being produced.

Plant with fern-like leaves is likely Dogfennel

What are these plants and are they edible?

Mui Sim Chan

The taller plant with fine, fern-like leaves is likely the Dogfennel (Eupatorium capillifolium). The leaves emit an odour when crushed. It is often mistaken for the dill herb (Anethum graveolens). It should not be consumed as it contains compounds that can affect the liver.

The shorter plant with broad leaves cannot be reliably identified without a clear photo of additional features such as its flowers. It could be a plant belonging to the daisy family (Asteraceae).