Root Awakening: Dracaena is infested with scale insects

Remove scale insects with summer oil

My Dracaena plant’s leaves have developed brown specks that leave yellow stains when scratched off. I have tried scraping the specks off and even pruning the leaves, but the leaves that regrow eventually develop the same problem.

Pearl Tong

The brown specks are scale insects, a type of sap-sucking pest. First, use a soft toothbrush to remove them. Next, spray the plant with summer oil, which is available at local nurseries, to suffocate the pests.

Ensure there is complete coverage of the plant and note that repeat applications are required to keep the pest population low. Dilute the pesticide and spray during a cooler time of the day to avoid burning your plant.

Plant is likely Wild Cinnamon

What is this plant?

Winston Lee

The plant is probably the Wild Cinnamon (Cinnamomum iners). It grows into a small tree and is native to Singapore. Its bark produces an inferior grade of cinnamon, and its leaves and wood can be used as spices.

Check root health, soil’s moisture level

This plant on my balcony does not sit in direct sunlight. The leaves have curled and the stem is droopy. Is there a way to revive it?

Lin Siuying

Your Philodendron plant has wilted from what appears to be a lack of water. How often do you water your plant? It should never be allowed to dry out and should be watered regularly to keep the root zone moist.

Also, check the health of the roots, especially if the growing media is moist. Roots that have rotted due to wet, poorly draining soil can leave the plant unable to take up water, causing it to wilt. If the roots are rotten or infested with pests, prune the top of the plant and try rooting it again.

This foliage plant needs four to six hours of filtered sunlight daily. It should not be grown in deep shade indoors.

Billygoat weed will smother other plants

This plant is growing in my vegetable garden and has a strong smell. What is it and does it have any uses?

Angus Ang

The plant looks to be the Billygoat weed (Ageratum conyzoides) and has uses in traditional medicine.

It is a weed that grows and spreads quickly, and can smother your plants. It is not advisable to cultivate it in your vegetable garden.

Fire Fern’s roots may be damaged

I repotted this oxalis fire fern at The Straits Times’ soil-less planting event, the ST Earth Day Glass Garden Workshop. However, the fern has been shedding leaves ever since. At the workshop, we learnt that the plants need to be watered weekly with water coming up to about one-third of the pot size. I also spray fertiliser about once a week or two. It is kept in the kitchen with indirect sunlight from the window. I have noticed that this fire fern absorbs water extremely slowly. Could it be over-watered?

Jamie Au

In the process of converting your Fire Fern (Oxalis hedysaroides) to growth in a soil-less mix, did you remove and wash the roots clean? This is a traumatic process for plants. The roots are not adapted to grow in water and, having likely been damaged in the process, the plant is unable to take up water effectively.

To salvage your plant, try enclosing it in a clear plastic bag. Cut away the corners of the sealed end of the plastic bag. This will create a humid environment that will reduce the loss of moisture by the plant and allow it to produce roots, thereby reducing the impact of transplant shock. The holes in the plastic bag permit air circulation and reduce heat build-up.

Place this set-up in a bright but cool location. Do not fertilise the plant at this stage.

After a week or two, if new roots have grown, open the bag and let the plant slowly acclimatise to the external environment. If the leaves no longer wilt, you can remove the bag and gradually move the plant to its final growing location, preferably one that gets filtered sunlight for four to six hours daily.