Root Awakening: Roselle plant needs direct sunlight; Spiked Pepper is a weed

Roselle seedlings (left) and spiked pepper plant. PHOTOS: ALICE CHUA, KAISER TAN

Zingiber ottensii is a collector's plant

What is this plant?

Abd Rahmat M

The plant is botanically known as Zingiber ottensii. It is a member of the true ginger family, Zingiberaceae.

It produces attractive inflorescences that arise from the base of the plant. It flowers when it is old enough and has produced a large enough clump of leaves.

The Zingiber ottensii is a member of the true ginger family. PHOTO: ABD RAHMAT M

The plant fares best in a moist, well-drained location with fertile soil and filtered sunlight. Mature plants take up some space and are often grown by plant connoisseurs with outdoor gardens.

Spiked pepper is a weed

What is this plant? I saw it growing in my garden a few months ago and was wondering if the leaves or fruit are edible.

Kaiser Tan

This plant is botanically known as Piper aduncum. Its common name is the Spiked Pepper. In Singapore, it occurs mostly as a weed in sunny areas and can grow up to a few metres high, resembling a small tree.

The fruit is reportedly used to flavour cocoa and as a substitute for long pepper. The leaves have antiseptic properties and are used to stop bleeding and treat ulcers. Do not self-medicate without the guidance of a certified practitioner.

Spearmint plant needs filtered light

What is this plant and are its leaves edible?

Jacob Ng

Fresh spearmint leaves can be used to flavour drinks and desserts. PHOTO: JACOB NG

Your spearmint plant seems to have rather thin stems and widely spaced leaves, which is a sign that it is not receiving enough light. Under good light, the leaves will be closer to the stems and the plant will look more robust.

You should gradually move the plant to a location where it can receive four to six hours of filtered sunlight. Mint plants must be kept moist at all times, and grow best in fertile, well-drained media.

Fresh spearmint leaves can be used to flavour drinks and desserts.

Roselle plant needs direct light to thrive

My two roselle seeds were sown a month ago and have germinated, but they appear long, thin and unhealthy. What should I do?

Alice Chua

It appears that your roselle seedlings have not been grown in a sunny location.

The roselle is a sun-loving plant and needs to be exposed to at least six hours of direct sunlight to grow well. A lack of light will produce long, lanky and weak seedlings with soft tissue that can have difficulty acclimatising to higher light levels without getting burnt. It is best to restart new seedlings under appropriate light levels.

Foliage plants lack sunlight

I bought these plants in a bid to cultivate a new hobby and naturally purify the air at home, but they are struggling despite receiving water, fertiliser and basic care. What do you suggest?

Valerie Tan

The plant with yellow variegated leaves is Dracaena reflexa, also known as the Song of India. The plant with broad green leaves is the Fiddle-leaf Fig (Ficus lyrata).

The Dracaena reflexa, also known as the Song of India (left) and the Fiddle-leaf Fig (Ficus lyrata). PHOTOS: VALERIE TAN

As both are sold as houseplants, many people unknowingly grow them deep inside the house or office, where light is lacking.

While the plants can tolerate short periods of low light, a prolonged lack of light will lead to their decline and they will become susceptible to pests and diseases. Move them to a spot which gets at least four hours of filtered sunlight. You can rotate them between the original display area and a spot with enough light for them to recover and grow.

Both plants can also be adapted to grow under direct sunlight, as seen in outdoor parks and gardens.

The burnt leaves of your Dracaena reflexa could also be due to a lack of water. Water your plant regularly to keep the roots moist and do not let them dry out completely.

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

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