Root Awakening: Water plants regularly; edible plants infested with sucking pests

Wilting money plant (left) and Boston ferns. PHOTOS: PRISCILLIA CHONG

Water plants regularly

My money plant is wilting, and my Boston ferns keep turning brown and shedding their green leaves, even though I mist them a few times a day. What should I do?

Priscillia Chong

It appears that your plants have not been watered regularly and thoroughly, so the root zones have dried out and caused the plants to wilt. The root zones of your plants should be kept moist, but not wet, at all times.

Plants deprived of water for a long time will have dead tissues, which appear as dry parts. Even if you give them water, the roots might be too damaged to take it up.

Depending on the growing environment and type of potting media, the watering frequency of plants may vary. It is important to water your plant thoroughly and let excess water drain out from the holes at the base of the pots. Excess water should be drained in this way to prevent the roots from drowning and mosquitoes from breeding.


Giant White Bird of Paradise needs water

PHOTO: KANTHIMATHI

My plant was healthy when I bought it, but the leaves are now turning yellow. I was told to water it once a week. What is wrong?

Kanthimathi

Your plant is likely the Strelitzia nicolai, commonly known as Giant White Bird of Paradise. The edges of the leaves have started to fold in and the lower leaves have turned yellow, which indicate that the plant has not been watered regularly and has dried out. Its pot is also rather small, meaning it will also dry out quickly. The recommended watering frequency is probably not sufficient for your plant.

Although drought-tolerant, this plant should not be allowed to dry out. You should water more regularly to keep the potting medium moist, but not wet, at all times. Also, consider moving it to a larger pot so it has more room to grow.


Edible plants are infested with sucking pests

PHOTO: MARGARET LEE KIM GEK

The older leaves of my kangkong, sweet potato leaves and coriander have spots. The kangkong and coriander are grown under white netting. Newer leaves do not seem to be affected. What is wrong?

Margaret Lee Kim Gek

The numerous minute spots on the leaves may indicate an infestation of sap-sucking pests. Try turning the leaves over to check for the presence of spider mites or whiteflies.

Summer oil, castile soap solution and pyrethrins are common pesticides that you can use to deal with such pests. However, to reduce the amount of pesticide used - and taking into consideration the difficulty of ensuring thorough coverage - you may want to remove heavily infested leaves and apply the pesticide at regular intervals to reduce the pest population.

You can also consider removing badly affected plants and allow the area to rest for a period of time. Practise crop rotation by growing an unrelated and more pest-resilient plant instead. Finally, check your plants regularly for any sign of pest infestation and take remedial action early. Harvest your produce to avoid overcrowding, and grow plants under ample sunlight and air circulation.


Orchids are from the Genera Dendrobium and Aranda

Dendrobiums (left) and Aranda Chark Kuan "Red". PHOTOS: CROSBY ONG

What are the names of my orchids?

Crosby Ong

The orchid in the first picture is Aranda Chark Kuan 'Red'. The two orchids in the second image are Dendrobiums; the one in the foreground is Dendrobium Red Bull, while the one with smaller pink flowers is likely a Dendrobium bigibbum hybrid.

All these orchids are epiphytic in their growth habit and need open, aerated growing media. They require some sunlight exposure and regular feeding with a water-soluble orchid fertiliser to thrive.


Plant is the Holy Basil

PHOTO: HSU LI REN

I bought a lime plant and was told the plant that came with it is not a weed, but an Indian herb used for cooking, and that it should not be discarded. What is it?

Hsu Li Ren

The plant in the picture is the holy basil (Ocimum tenuiflorum). The scent and flavour properties of this species are different from the common sweet basil (Ocimum basilicum). Its leaves are used by various ethnic groups. For example, you can use them to brew tea or stir-fry them with the meat of your choice in a Thai-style dish.

  • 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.
  • Have a gardening query? E-mail it with clear, high-resolution pictures of at least 1MB, if any, and your full name to stlife@sph.com.sg. We reserve the right to edit and reject questions.

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