Root awakening: Peace Lily needs more water, bigger pot

Peace Lily
Peace LilyPHOTO: WU XUN
Desert Rose
Desert RosePHOTOS: JIM WEE
Bonsai
BonsaiPHOTO: STEVEN CHAN
Haworthia
HaworthiaPHOTO: KEVIN HO
Dragon Blood Tree
Dragon Blood TreePHOTO: IRENE TAN

Peace Lily needs more water, bigger pot

The leaves of this plant, which is kept indoors, are taking turns to yellow. Is this due to underwatering or lack of sunlight? I water the plant every other day, making sure that the roots are dry between watering. How do I care for this plant? Wu Xun

The plant is called the Peace Lily and its botanical name is Spathiphyllum wallisii.

The yellowing leaves appear to be those that are older and the reason may be due to the lack of water. The pot appears to be too small for the plant. The plant will dry out quickly due to the small volume of soil.

You should move the plant into a slightly larger pot and the soil should be kept moist most of the time. Allowing the root ball to dry out a little is good as it allows some air to get to the roots. The plant, however, should not be allowed to dry out totally.

Although the Peace Lily is often said to be a shade-tolerant indoor plant, it does better if it can get four to six hours of filtered sunshine daily.

Desert Rose is fruiting

This plant has been with me for a few years. This is the first time I have seen an unusual growth at the tip which is usually blooming with flowers. What is the growth? Jim Wee

The plant is commonly known as the Desert Rose (botanical name: Adenium obesum). It is grown mainly for its showy flowers and, in some specimens, its growth form, which features a swollen stem base known as a caudex.

The structure growing at the tip of a branch is the fruit of the plant. The fruit are produced in pairs.

You can wrap them using an organza bag to catch the seeds when the ripened fruit split open. The seeds have a feathery fluff that facilitates their dispersal by wind.

Clean decayed part of bonsai to prevent spread

I have a bonsai tree in my garden and the trunk is badly decayed. Is the tree dying? What can I do to save it? The tree is still fruiting occasionally. I was told it is a cherry tree. Steven Chan

The bonsai is sculpted from a plant commonly called Surinam cherry or Brazilian cherry. Its botanical name is Eugenia uniflora. Its fruits are edible when fully ripe where they turn a deep red colour.

The decayed portion of the trunk needs to cleaned out to prevent the decay from progressing.

You need to keep the area dry in the future to prevent infection and decay. The cleaned area does not need any wound sealant. Its application can do more harm than good to the plant.

Some pruning of the branches can be performed to rejuvenate the tree.

Repot Haworthia with coarse growing material

What is the name of the succulent and how do I take care of it? Can the plantlets around the sides be used for propagation? Kevin Ho

The plant is a species of Haworthia and it is most probably the Haworthia turgida.

Unlike most succulents, Haworthia is best grown under four to six hours of filtered sunlight daily. Intense sunlight can burn the leaves of this plant.

It appears that the plant is still grown in its original cocopeat-based substrate. This substrate can hold too much moisture, which can cause the roots to rot.

Most hobbyists in Singapore will carefully remove the cocopeat and repot the plant in a coarser and more well-draining growing media, such as Akadama, which is a granular, clay-like mineral, mostly used for growing bonsai.

Other popular coarse materials used to grow Haworthia include pumice and lava sand.

The young plants growing on the side of the mother plant can be removed and potted separately - do this when they are large enough to handle and when they have produced some roots on their own.

Dragon Blood Tree favoured for stately form

What plant is this? Irene Tan

The plant is botanically known as Dracaena cochinchinensis and its common name is Dragon Blood Tree. It is often sold as a large and much branched specimen. It is admired for its stately form and hence used as a focal point in outdoor gardens.

It thrives when grown under direct sunlight and in well-drained soil.

•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@sph.com.sg

A version of this article appeared in the print edition of The Straits Times on March 09, 2019, with the headline 'Root awakening'. Print Edition | Subscribe