Root Awakening

Cockscomb flower produces seeds after flowering.
Cockscomb flower produces seeds after flowering.PHOTO: HASSAN ALI
Aloe vera has fungal disease.
Aloe vera has fungal disease.PHOTO: ROSALIND SOH

Cockscomb flower produces seeds after flowering

What is the name of this flower ? How do I collect the seeds for germination?

Hassan Ali

The plant is commonly called the cockscomb flower due to its crested portion of the inflorescence resembling a rooster's comb. It is a festive plant for Chinese New Year and its botanical name is Celosia cristata.

The plant behaves like an annual, which means it declines after flowering and producing seeds. The seeds are small and black and they can be collected from a faded inflorescence.

Cut the faded inflorescence and hang it upside-down to dry. Seeds can be harvested by rubbing them off the portion found just below the crested flower head.

Aloe vera has fungal disease 

Why does my aloe vera plant, which is placed in the corridor, have black spots?

Rosalind Soh

Your aloe vera plant is likely not receiving sufficient sunlight for growth and the root zone may be too wet. Together, such conditions can make your plant more prone to getting fungal leaf spots.

Infected leaves will not revert to normal and if conditions do not improve, fungicides are of little help to improve the situation.

This sun-loving plant needs to be grown under at least six hours of direct sunlight to thrive. Plants grown under direct sunlight produce short, thick and stiff leaves that are more resistant to fungal disease.

When the plant gets optimal sunlight intensity, the issue will usually resolve on its own - new leaves that are produced will be fungal spot-free. Shelter the plant from rain during the rainy season.

Also, ensure the soil used to grow your plant has coarse gritty material which will permit fast drainage of water and good aeration of the roots.

Spider plant may be too dry and exposed; air plant has just finished flowering

The leaves of my spider plant (photo left) started to fold and the plant has become greyish. It has adequate sunshine since it is grown on my kitchen window ledge. I water it once a week. What could be the cause? For my air plant (photo right), it has lost its yellow glow. When I bought the air plant cluster two months ago, three of the blooms had a glowing yellow hue and were flowering. That yellow glow has since turned green. Is this normal? I mist it on alternate days.

Betty Ho

Your spider plant (botanical name is Chlorophytum comosum) may be in an overly sunny location where it is drying out, leading to the symptoms described.

The plant prefers to be grown in a semi-shaded location, where it can get four to six hours of filtered sunlight daily.

Ensure the potting mixture is moisture-retentive and moist at all times. It should not be allowed to dry out.

Your air plant is likely the Tillandsia ionantha cultivar named Druid.

This cultivar, when in bloom, will feature leaves that surround the yellow flowers.

When the flowers fade, the leaves turn green again.

Generally, air plants of this species are easy to grow. They need a humid area with four to six hours of direct sunlight to thrive.

Depending on how dry and windy the area is, plants need to be given water either by regular misting or soaking in water for several hours.

Ceylon spinach has fungal leaf spots

I have two species of edible vegetables which grew quite well. Over the months, however, red spots were seen on the leaves (above) and stems. Are the leaves still edible? What is the reason for the red spots? Also, what are the names of these vegetables?

Ellen Ho

Your Ceylon spinach plants (Basella rubra with red leaf stalks and stems; Basella alba for the all-green plant) are infected by a fungal disease.

As the plants are grown for consumption, it is not recommended you use chemical fungicides that are generally more effective.

As such, remove all infected leaves and discard them with household trash to reduce the spread of the disease.

To promote healthy plants that are less prone to the disease, grow them in a sunny location with good air circulation.

• Answers by Dr Wilson Wong, an NParks-certified practising horticulturist and park manager. He is the founder of Green Culture Singapore and an adjunct assistant professor (Food Science & Technology) at the National University of Singapore.

• Have a gardening query? E-mail it with clear, high-resolution pictures of at least 1MB, if any, and your full name to stlife@

A version of this article appeared in the print edition of The Straits Times on January 12, 2019, with the headline 'Root Awakening'. Print Edition | Subscribe