Root Awakening

Cherry tomato leaves
Cherry tomato leavesPHOTOS: ANGELINE WANG, LIM YANG SOON, SILVANA MONTONI, TANG POH SENG
Garden pests
Garden pestsPHOTOS: ANGELINE WANG, LIM YANG SOON, SILVANA MONTONI, TANG POH SENG
Purple Millettia and its botanical name is Callerya atropurpurea.
Purple Millettia and its botanical name is Callerya atropurpurea.PHOTOS: ANGELINE WANG, LIM YANG SOON, SILVANA MONTONI, TANG POH SENG
Fruit-bearing ciku tree partially uprooted
Fruit-bearing ciku tree partially uprootedPHOTOS: ANGELINE WANG, LIM YANG SOON, SILVANA MONTONI, TANG POH SENG
Trailing Jade Plant (botanical name - Peperomia rotundifolia).
Trailing Jade Plant (botanical name - Peperomia rotundifolia).PHOTOS: ANGELINE WANG, LIM YANG SOON, SILVANA MONTONI, TANG POH SENG

Slugs attacking vegetable seedlings; tomato plant has nutrient deficiency and diseases

My garden is infested with pests that eat my vegetable seedlings. They typically appear after it rains at night. What are these pests and how can I get rid of them? Also, my cherry tomato leaves have been turning yellow despite regular watering. What is wrong with them?
Lim Yang Soon

Your vegetable seedlings are likely being devoured by slugs. They are active in wet weather and at night when they emerge and consume tender plant parts.

You can either stay up to catch them when they are active or use baits (often poisoned) to lure and kill them.

Baits that are safe for humans and pets include tea seed meal and iron phosphate pellets. These alternatives are safer to use and more durable in wet weather than the more common, pink, metaldehyde-based pellets.

The tomato plant appears to be a complicated case due to a variety of symptoms. The yellow leaves with green veins may point to a nutrient deficiency. In such cases, you need to check the pH level of the soil to ensure that it is in the optimal range for the plant so that essential nutrients are available for the plant to absorb.

The browning and dropping of leaves may be due to a fungal or bacterial disease. At this advanced stage, it can be difficult to manage. The issue may have occurred during a wet spell and if your plant is grown outdoors.

Plants should be grown in well-drained soils and sheltered from heavy, frequent rains. A clear plastic shelter can be constructed over the plant for this purpose.


Purple Millettia's dense crown offers shade

What is the name of this tree? It has an interesting fruit.
Tang Poh Seng

The tree is likely the Purple Millettia and its botanical name is Callerya atropurpurea.

It produces ornamental flowers and has a dense umbrella-shaped or round crown that offers much shade when the tree is mature.

It used to be grown in Singapore's parks, gardens and along its roads to provide shade.


Get arborist to check tree 

A few weeks ago, my healthy, fruit-bearing ciku tree, which is more than 30 years old, fell to the side and was partially uprooted.

But it is still alive.

Would it be worth the effort to transplant it to another location or should I put it back upright? 
Silvana Montoni 

For major tree issues like yours, it is recommended that you engage a certified arborist (a tree-care professional certified by the International Society of Arboriculture) to examine the tree.

The tree may have internal issues that are not immediately evident and require special instruments for examination.

The arborist will prescribe remedial actions after an inspection.

You also need to consider future maintenance costs to keep the tree healthy and safe for you and your neighbours.


More aerated soil for Trailing Jade Plant

Last month, I moved this plant into a bigger pot with organic potting soil - which is different from the original soil - and it has not been growing as fast and the leaves are drooping. What should I do?
Angeline Wang

The plant appears to be the Trailing Jade Plant (botanical name - Peperomia rotundifolia).

After taking stem-cuttings or being transplanted, plants often need to produce new roots before growth commences.

This plant is sensitive to wet feet, so an organic material-based growing mix may prove to be too moist and can cause the roots and stems to rot. As a result, leaves may also drop.

It is recommended that you incorporate a little gritty material like coarse sand or fine grade expanded clay pellets to help open the mix a little to permit drainage and aeration.

• 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 November 10, 2018, with the headline 'Root Awakening'. Print Edition | Subscribe