Root Awakening: Japanese cucumber needs proper pollination to fruit

Plant needs hand pollination to fruit

The flowers of my Japanese cucumber develop into tiny cucumbers, but once these grow to about 6cm long, they turn yellow and fall off. Why is this happening?

Ng Kim Liang

The lack of fruit production could be due to incomplete pollination. If your garden lacks natural pollinators such as bees, you need to perform hand pollination. Find a male flower and use a small paintbrush to pick up pollen from the centre. Transfer that pollen into the centre of a female flower. The female flower has an ovary behind the petals which resembles a small cucumber fruit, while the male flower does not.

Tomato plant infested with mites

Our tomato plant’s leaves have started browning, especially those near the top. We water the plant once or twice a day and it has not fruited yet. What is wrong?

Ivy Chew Wee Chern 

The new shoots of your tomato plant appear to have been infested with microscopic mites, which could be either broad mites or russet mites. You will need to repeatedly and regularly apply diluted organic pesticides, such as lime sulphur, to control the pest population. Apply only during the cooler periods of the day to avoid burning the plant.

Umbrella plant lacks nutrients

What plant is this? Why have the tips of the leaves dried up?

Philip Thiah

From the chlorosis in the leaves of your Umbrella Plant, which is a species of Schefflera, it seems to be lacking in nutrients.

Has the plant been grown in the same medium for a long time? Potted plants grown in the same media for too long may exhaust all available nutrients. The growing medium could also be compacted, meaning it is no longer well-draining and properly aerated. Its chemical properties may also have changed. All these factors may impede plant growth.

Try moving the plant into a new pot of fresh growing media. Fertilise it regularly with a water-soluble fertiliser. You can both drench the root zone with the fertiliser solution and spray a diluted version onto the leaves. 

Hibiscus infested with sap-sucking insects

What are these parasites on my hibiscus and how can I prevent another attack? There are also ants leaving black particles on the hibiscus and daun limau perut. Will spraying diluted neem oil help? What are the ants after?

Joyce S.Y. Tan

It appears that your plants have been infested with scale insects. These suck sap and excrete honeydew, which ants then harvest for the sugar content.

First, use a soft brush to remove the pests you can see. Next, mix neem or summer oil – an organic pesticide which suffocates pests and is available in local nurseries – in water and spray thoroughly on all parts of the plant. Repeated applications may be required. Do this during the cooler part of the day to avoid injuring your plant.

Lipstick Plant may have fungal disease

My Lipstick Plant is in my service yard, which is a well-ventilated area without direct sunlight, and is watered once a week. I also have a grow light in place for when the weather is cloudy or rainy. A few months ago, I noticed brown spots appearing on the leaves. The affected leaves eventually turn completely brown and fall off. What is wrong?

 Ahmad Shuhaimi

The brown patches may have been caused by a fungal disease. These affect plants which have been weakened by sub-optimal growing conditions, or which have sustained injuries that allow pathogens to enter and infect the plant tissues.

Lipstick Plants need filtered sunlight to thrive, so your grow lights must be switched on at the required intensity for a long enough period for your plant to benefit. Although the Lipstick Plant is an epiphyte and thrives in porous growing media, ensure that it does not dry out, since you water only once a week. The roots should be moist most of the time. Protect the plant from heavy rain, which can injure the leaves, with a rain curtain. 

Another possibility is phytotoxicity, which is caused by the application of chemicals such as pesticides or fertilisers. Always test new chemicals on a small part of the plant or use a lower dosage to limit the potential for injury to your plant. The damaged areas are permanent, but new growth will replace them.