Give aroid cutting more time to take root

I was gifted a cutting of Rhaphidophora tetrasperma in a mix of perlite and clay pellets. It has no roots yet, but appears to have two growth nodes: one high up on the stem and another just on the surface of the growing medium. How can I encourage its growth?

Diane Yeo

Rhaphidophora tetrasperma, colloquially known as the Mini Monstera, is a common foliage aroid species. Your stem cuttings need time to take root and produce new growth. Roots will be produced first, as the plant needs them to take up water and nutrients.

You seem to be growing the cutting via a semi-hydroponics system. Add a diluted nutrient solution just below the roots once they have been produced. Avoid flooding the root system later on, as this can cut off oxygen and kill it.

Since the cutting has no roots yet, fill the container until the cut ends are submerged in water, so they do not dry out.

Stressed plants more prone to infestation

My dwarf cucumber plant, which I placed in my HDB corridor, was fruiting well, but has been swamped with spider mites. They seem to prefer this plant to the others around it. How can I treat the plant?

Adrian Ling

Certain plants can be difficult to grow in high-rise environments, which are often dry and windy. The resulting stress can make the plant more prone to infestation by pests such as spider mites. As the mites’ natural predators are likely absent from your plants’ current growing environment, infestations can be challenging to manage. However, you can attempt to do so by spraying summer oil to suffocate the pests.

Cucumbers need more humid, less windy conditions. While some gardeners may recommend regular misting to increase the ambient humidity, this method may not succeed given the plant’s open-air location. It is best to grow something more suited to a high-rise environment.

Protect Aloe vera from rain

I have tried wiping these black marks off my Aloe vera, but they are not coming off. What are they?

See Soo Eng

The black marks could be due to disease, which occurs when this species is grown under shade and exposed to rain. This can also lead to a waterlogged root zone. A lack of light can cause the leaves to become soft, floppy and prone to infection.

The marks could also be injuries from rain or from spraying too high a concentration of fertiliser or pesticide. Use lower concentrations of pesticide and test on small parts of the plant first.

The spots are permanent. In Singapore, it is best to grow this plant in a protected spot with a well-draining growing mix. It needs good air circulation and direct sunlight for at least six hours a day.

Mosquito Plant is sensitive to waterlogging

I have had this plant for about nine months. I understand I should not water it too much as it can cause root rot. About three weeks back, I noticed the branches drooping. How can I salvage my plant?

See Teck Meng

You are correct that the Mosquito Plant (a cultivar of Pelargonium) should not be over-watered, which can lead to root rot or disease. However, the soil can still be waterlogged even if you do not over-water. The growing mix of your plant looks clay-like and too wet. You may want to take stem cuttings and try to root them to start anew.

This plant should be grown in a gritty, well-draining mix and sheltered from the rain. It needs a sunny spot and its root zone should be allowed to dry out slightly, but not too much, before watering again.