Root Awakening: Lemon tree infested with scale insects

Use summer oil to manage pest population

What is this pest and how do I get rid of it?

Adrian Ling

The white cotton-like masses are likely scale insects, a type of sap-sucking pest. If the infestation is minor, you can use a strong jet of water to wash them off or remove them manually using a toothbrush.

Repeated applications of summer oil pesticide can be used to manage their population. The pesticide works by suffocating them and thorough coverage is essential. 

Pitcher plant’s flowers can be pruned

My pitcher plant’s flowers are not as abundant as before. Do the flowers have uses? How can I make the plant produce more pitchers?

Kok Kah Wei

The lack of pitchers could be due to the production of longer, vine-like stems on older plants. As they grow, plants may produce upper “pitchers” or tendrils to help itself climb. You can prune the plant to encourage it to produce basal pitchers again.

The flowers you have on the plant are male. They can also be pruned unless you are collecting pollen to pollinate female flowers.

Corky growth could be due to age or moisture

I have had this cactus for years and it has developed grey patches. Is this corking or an infestation? The patches are hard, not soft or mushy. Can I save the plant?

Cynthia Wong

The corky growth at the base of your cactus (Cereus species) is common in larger specimens. This is thought to be due to age, and the corky growth is a response to provide the support and protection the plant needs.

Another possibility is excessive moisture present in the growing media. To reduce the likelihood of corky patches developing, grow the cactus in a porous, well-draining mix and allow it to dry out periodically.

Protection from rain is essential to reduce the likelihood of wet feet. Grow the plant under a clear shelter that lets light through but keeps out rainwater.

Holy Basil requires sunlight and moist soil

What is wrong with my plant? I water it every other day, but the leaves are withering and falling.

Gabriel Chia

Your Holy Basil (Ocimum tenuiflorum) will grow best in a location that gets at least four hours of direct sunlight a day.

Its symptoms indicate a lack of water. Try replanting it in a bigger pot, as more soil will retain more moisture for the plant.

You may also want to prune it periodically. Reducing the number of leaves will reduce the moisture lost through transpiration and help the plant retain water.