Root Awakening: Cucumber plant is diseased

Japanese cucumber has fungal disease

What is the cause of the yellow spots on my Japanese cucumber? Also, what is an environmentally friendly way to get rid of snails?

Adrian Ling

Your cucumber plants are infected with a fungal disease. Once infected, the marks on the leaves are permanent and can spread to other plants. Choose resistant varieties where available.

Avoid getting the leaves wet. Growing your plants under a clear shelter may help. Also, do not overcrowd your plants, as they must each get ample sunlight and air circulation.

Spray a preventive fungicide such as copper soap to reduce the severity of the disease.

To prevent or reduce damage from snails, deny them access to your plants by putting up a netted enclosure, or raising or hanging your plants.

Also, clear your garden of potential hiding spaces for snails. They like to hide in dark, moist areas like upturned flower pots and dense groundcover plants.

Remove snails by hand whenever you see them in the garden. They are usually more active later at night. Alternatively, you can build snail traps – instructional videos are available online – with their preferred food as bait to attract them. Trapped snails can be removed and discarded.

Avoid the use of commercial snail pellets, which contain metaldehyde, if you are concerned about environmental contamination.

Test irrigation method early to ensure reliability

The article “

Nine PlantToks which may kill your plants

I will be going for a long holiday in September. I intend to place a 1.5-litre bottle of water over a terracotta cone measuring 17cm in height. The pot’s internal diameter is 32cm. Will the water from the cone be able to wet the soil enough to reach all the roots?

Danny Yeo

When trying any irrigation method to replace regular watering during a long absence, test it well in advance of your departure to ensure its reliability. Some of the tested methods include a drip irrigation system linked to a timer, as well as self-wicking plant pots.

Alternatively, ask a neighbour or friend to water your plants, or engage “plant hotel” services to care for them while you are away.

Guava tree in decline due to trunk defect

My marcotted guava tree is about 10 years old and has fruited well for the past five years. Of late, however, its leaves have dried up and the affected branches have turned pale green. I have pruned the affected branches, but was unsuccessful in staving off the spread. I am now down to a single healthy branch. What should I do?

Theang Ai Chen

It appears the original trunk of the guava plant either has a defect or is diseased. Its vascular system is affected, which prevents water from being taken up to the rest of the plant. The tree is difficult to save at this stage and will have to be removed.

Look up reliable resources in tree pruning, branching structure and safety to keep future trees in good health. Incorrect pruning methods can lead to poor tree health and, potentially, tree failure.

Root and acclimatise cuttings before moving them

I repotted my plant in a longer container to avoid overcrowding. Some parts have bloomed, but there are also shrivelled leaves. What is wrong and how can I care for the plant?

Jacilyn Siew

Your plant is the Lantana (botanical name: Lantana camara). It is not advisable to simply insert fresh, unrooted stem cuttings into a growing mix, as they will be unable to take up water. It is best to first root them in a shaded and protected site and let them acclimatise to the new growing medium before they are gradually moved to the new site.

Note that Lantanas do not tolerate waterlogging. Ensure the soil you use is well-draining, as wet feet will kill the plants over time. Water your plant only after the root zone has slightly dried out.

Overfertilising plants can lead to brown leaf tips

I have noticed some changes in my Peace Lily’s appearance. The plant is healthy, but the leaf tips are turning brown. What is wrong? I water it twice a week, place it near a window and fertilise it once a month.

Also, how can I encourage my Peace Lily to flower? It bloomed once when I first took it home, but has not since. What are the key factors influencing its flowering cycle and how do I stimulate the process?

Tan Poh Keam

Is your Peace Lily grown using hydroculture? If so, you need to regularly change the nutrient solution, as mineral salts can build up inside. Excess salts not taken up by the plant remain in the root zone, which can cause the leaf tips to turn brown. This can happen with soil-grown plants too.

It is best to use slow-release fertilisers for soil-based plants, and change the nutrient solution from time to time to reduce the chance of leaf tips browning.

Another possibility is that your plant is sensitive to the fluoride in tap water. Some gardeners collect rainwater or use reverse-osmosis water for their plants.

Although the Peace Lily is thought of as a shade-tolerant plant, it tends to remain vegetative when grown in a location with too little light. Moving it to a site that gets at least four hours of filtered sunlight daily may promote flowering.