Root Awakening

PHOTO: JEAN ANG
PHOTO: VICTOR CHAN
Chinese Arrowhead
Chinese ArrowheadPHOTO: WILSON WONG

Lack of iron or manganese reason for leaf differences

I took seeds from a Petunia flower and planted them in this pot. However, two different plants grew from those seeds. Why is this so?

Jean Ang

There could be a problem with the growing media or there is a pest infestation of the roots. It is not likely a viral disease as the leaves of the plant on the far right appear to be normal in shape and size.

But those leaves show signs of a lack of iron and/or manganese. This could be due to overly high pH level in the soil. If you created your own soil mix, were the components evenly blended?

From previous research done by horticulturists, you may want to feed your plants this way: Use regular soil drenched with a diluted water-soluble fertiliser that contains chelated iron and manganese (in the form of EDTA). This has been shown to alleviate the symptoms mentioned.

Next, carefully take the plant out from its pot and examine its roots. Infestation by pests such as root mealy bugs can prevent a plant from absorbing water and nutrients efficiently.


Cypress Vine not common in Singapore

I found this creeper with red flowers and a single petal growing on my fence. What plant is it and is it rare? How do I grow more of it?

Victor Chan

The vine is botanically called Ipomoea quamoclit. Other common names are Cypress Vine, Cypressvine Morning Glory and Cardinal Creeper. It is a relative of the common morning glory. It is not a common flowering vine in Singapore. It is a semi- perennial plant and should continue to grow for some time.

Plants, as they age, may lose their vigour and look straggly - this is perhaps when you should start growing new plants.

The Ipomoea quamoclit grows easily from seeds and these can be collected from ripe, dried fruits that form on the vine. There are two other varieties that produce white and pink flowers.


New shoots of Mother-in-law's Tongue can be repotted


PHOTO:
 FONG SAU YEE

I have this pot of Mother-in-law's Tongue. Recently, two new shoots grew. Is it safe to transplant these new shoots into another pot ?

Fong Sau Yee

The Mother-in-law's Tongue - its botanical name is Sansevieria trifasciata - spreads via underground stems, or rhizomes, that extend from the mother plant.

Offsets can be moved to a new pot when they are about half the size of the mother plant.

You can lift the plant out of the pot and check if the younger plant has produced roots.

Use a sharp knife to cut the offset from the mother plant.

Allow the wound to heal and dry before you plant it in a new pot of fresh soil.


Pencil tree has toxic substances in sap


PHOTO: SALLY HOON

What is this plant?

Sally Hoon

The plant is botanically called Euphorbia tirucalli and it belongs to the same plant family as the Christmas Poinsettia (Euphorbiaceae). It is known via a range of common names such as Indian tree spurge and pencil tree. It thrives in well- draining soil and under full sun and can tolerate some shade.

It has some medicinal uses, but must be used with caution - some toxic substances have been found in the milky sap of the plant.


Tip: Chinese Arrowhead good as snack, festive plant

These are the corms of the Chinese Arrowhead, known botanically as Sagittaria latifolia. They are imported to Singapore close to Chinese New Year and sold in vegetable stalls.

They are processed in many ways for consumption. One of the more popular methods is to slice the corms thinly and deep-fry them to make Chinese Arrowhead chips.

They can also be grown in a pot with water and pebbles as a festive display plant.

The corms are short-lived aquatic plants that grow in the tropics. It is best to give them some morning sun for several hours to ensure the plants develop sturdier leaf stalks. Arrow-shaped leaves will emerge and grow upwards after some time - symbolic of progress in the new year.

  • Answers by Dr Wilson Wong, a certified practising horticulturist and founder of Green Culture Singapore (www.greenculturesg.com). He is also an NParks-certified park manager.
  • 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
A version of this article appeared in the print edition of The Straits Times on February 06, 2016, with the headline 'Root Awakening'. Print Edition | Subscribe