Root Awakening: Papaya fruit must be picked upon maturity

Papaya is a climacteric fruit

I grew this plant from the seeds of a Thai papaya. I harvested one fruit when it was still green, and it stayed that colour and rotted on the shelf. I left another fruit on the tree, and it remained green for three months before turning orange. Why is it that I cannot harvest the plant when it is green, like those sold in the market?

Raymond Yeo

The papaya is a climacteric fruit that will ripen when it is picked. To ripen properly, it needs to be a whole fruit which is not infested by pests and has reached physiological maturity – that is, having reached its maximum size based on the prevailing growing conditions and cultivar characteristics.

When a fruit is picked before this stage, it may not ripen properly. Pick fruit at the right stage of development.

Beetle grubs are common in immature compost

I occasionally find these grubs in soil which has compost materials. I suspect they might be harmful to my plants. How can I get rid of them?

Tan Boon Keng

Beetle grubs are part of the plant decomposition cycle and feed on woody plant waste. Their presence indicates that the process is ongoing.

Use only mature compost if you are growing plants that may be damaged by these grubs. These include seedlings and some herbaceous plants with fine roots.

Partially composted materials like wood chips can be used as mulch for more resilient woody shrubs and trees.

Okinawan spinach, Brazilian spinach are edible and easy to grow

What are these plants and can they be eaten raw in a salad? How do I propagate the plant in the rectangular pot?

Qiu Xin Hui

The plant in the round pot is the round-leaf version of the Okinawan spinach (Gynura bicolor) and the one in the rectangular pot is the Brazilian spinach (Alternanthera sissoo).

Both plants are great for new gardeners to grow and can thrive in semi-shaded conditions. They propagate easily via stem-cuttings and are perennial.

You can take tip cuttings and plant them directly in the soil – the growing container should be placed in a bright and cool corner – and let them take root before moving them to the final growing location.

They root easily in a cup of water too.

Both vegetables can occasionally be eaten raw in small quantities, but are best enjoyed when cooked by lightly blanching them to improve their texture.

Incomplete pollination, environmental stress can cause young fruit to be aborted

Once the fruit of my seed-grown bittergourd are about 3 or 4cm long, they turn yellow and fall. What is wrong?

Thomas Lee

A bittergourd’s fruit development may fail due to a lack of pollination. If there are no bees or other pollinators in your garden, you may need to perform hand pollination on the female flowers to promote fruit production. Many videos online will demonstrate how to identify male and female flowers, and how to perform hand pollination.

When plants are fruiting, ensure the plant is not stressed. Heavy rainfall can flood the roots, and hot and dry weather can dry them out. Ensure the water needs of your plant are met.

When the young fruit start to swell, make a protective paper jacket around them to reduce the likelihood of fruit flies or any other burrowing pests from damaging the fruit.

Shade-tolerant plants still need light

What are some suitable plants, for indoor environments, that require minimal water and sunlight?

Jenny Pon Wai Wan

All plants require light to thrive. Some plants may be shade-tolerant, but even they will not survive if placed in deep shade.

Consider installing grow lights, which are LED lights that can be used to grow plants indoors.

Check with the vendor on the number of lights you need, how far away you need to place your lights and the number of hours that they need to be switched on for optimal plant growth.

Without more information on the intensity and duration of light, it is difficult to be able to provide a list of plants that you can grow. However, foliage plants are more suited for low-light areas. You can consider the Zanzibar Gem (Zamioculcas zamiifolia) or various colourful species of Ardisia.