Root Awakening: Philodendron cultivar in decline

Philodendron needs more light

My plant was healthy and green (first photo), but it has been shedding leaves and its stems have stopped growing (second photo). What is this plant and how can I keep it from deteriorating further? Why are the leaves turning yellow with spots and falling thereafter? Should I remove the stunted stems from the pot?

Bernice Uta Phua-Ang

The plant you have is a Philodendron cultivar named Birkin. Its overall decline is likely due to a lack of light. Philodendron plants grow best with at least four hours of filtered sunlight a day so, if its current location lacks natural sunlight, you may want to install grow lights and leave them on for about 12 hours a day.

Note that the grow lights must be intense enough to support the growth of your plant. Place them near the plant, but not so close that the leaves are burnt.

Marcotting must be done on mature plant

My marcotted mango plants have grown but not flowered for more than two years. What should I do?

Lau Kwok Nam

Plants need to be physiologically mature before they start flowering and fruiting. Was the marcotting done on a plant that has flowered and fruited before? If the plant is not physiologically mature, the marcots will likely be similar. 

Also, was the mother plant grown from the seeds of a market-bought fruit? The growth of the new plant can be unpredictable as such plants do not breed true and may not flower or fruit.

Note that mango plants need to be grown under full sun. The lack of light can cause them to remain largely vegetative. 

Papaya plant likely diseased

My papaya plant’s (foreground) leaves are discoloured. What is wrong? My other papaya plant was fruitful, but suddenly stopped flowering.

Wong Sik Yan

Your papaya plant seems to have a viral disease. These are not curable, so affected plants should be removed and discarded with general waste.

Such diseases spread via sap-sucking insects such as aphids, whiteflies and cutting tools. If you have been pruning the affected plant, do not use a contaminated cutting tool on other plants without sterilising it first. Keep the population of sap-sucking insects in check to reduce the spread of disease.

Alocasia infested with spider mites, needs better air circulation

I recently noticed many small mites on the surface of my plant’s leaves, and sprayed neem oil once a week. Yellow spot and white patches started appearing on the leaves, so I stopped. I now “shower” the plant with water twice a week to wash away the mites. New leaves are growing, but they have holes. The plant is not grown in direct sunlight. What should I do?

Peter Yeo

Most foliage plants do not grow well in dim, dry and stuffy indoor environments. Alocasias are best grown in a location with filtered sunlight or under grow lights. The lack of light will lead to etiolated and weak plant growth, and poor health will make the plant vulnerable to attacks from pests such as spider mites.

It may be that your plant’s growing environment is too dry. Washing plants may provide only temporary relief, and a misting system switched on at intervals throughout the day may be a better solution.

Also, ensure there is air circulation. This will create humidity changes necessary for leaf development. Poor circulation can cause leaves to unfurl and distort, as seen in the picture. You can use a fan at low speed to move air around. 

Fiddle-leaf fig is sunburnt, caladium not self-pollinating

I grow a fiddle-leaf fig and a caladium on my north-facing balcony under full sunlight. Is my fiddle-leaf fig sunburnt? Also, the caladium has grown its first flower. Will it self-pollinate?

Jen Wong

Your fiddle-leaf fig appears to be sunburnt. Although this species is an outdoor plant and needs direct sunlight, it may be that your plant was previously grown in a shady spot and is being burned by the more intense light. However, new leaves grown in the new environment will adapt to the higher light levels.

As for the caladium, the flower is not self-pollinating. However, there is nothing you need to do if you are not interested in plant breeding. Such a task requires some knowledge, time and space to grow the seeds produced. 

To have a better chance of producing fruits with viable seeds, you would need to take pollen from another, genetically different plant. Plants sold in nurseries are typically vegetatively propagated and genetically similar.