Root Awakening: Oldenlandia is a weed

Straits Times

3 days ago

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Oldenlandia corymbosa is often seen in flower pots, parks and gardens.
Two-flowered Oldenlandia has medicinal uses
Are these weeds? They sprout up quickly every time I clear my planting bed to sow new seedlings.
Caleb Tan
This plant is a weed commonly seen in flower pots, parks and gardens. Its botanical name is Oldenlandia corymbosa and it is known by common names such as Two-flowered Oldenlandia, Flat-top Mille Graines and Old World Diamond-Flower. It has been used in traditional medicine.
Mistletoe growing on hibiscus plant
Mistletoe is a parasitic plant that attaches to a host via a structure called a haustorium.
PHOTO: JOYCE TANG
My sister's hibiscus plant is sprouting long, smooth, lance-shaped leaves instead of the usual serrated leaves. What is happening?
Joyce Tang
The new growth is that of a mistletoe. A parasitic plant, it attaches to its host plant via a specialised structure called a haustorium.
If your hibiscus plant is healthy, the mistletoe is not a threat. Over time, however, it may grow bigger and its weight may affect the hibiscus' growth. You can prune it at the base of the haustorium or remove the affected branch of your hibiscus, whichever is easier.
Hibiscus requires direct sunlight to thrive
A windy environment can also cause a plant to dry out prematurely.
PHOTO: JACILYN SIEW
Most of my potted hibiscus plants are blooming, but two pots have large leaves and no flowers, as their buds just drop over time. I have tried spraying neem oil, adding fertiliser and inspecting for bugs. I also ensure the plants get many hours of bright light. What is wrong?
Jacilyn Siew
The hibiscus needs direct sunlight for optimal growth and development. A windy environment such as a high-rise balcony can also cause the plant to dry out prematurely, especially if it is grown in a small pot. A moisture-stressed plant can abort its buds.
You may need to provide some sort of wind protection for your plants and move them to bigger pots if they dry out quickly.
Frequent pruning can prevent oleander from flowering
To promote flowering, ensure the growth site is well-draining and do not over-water.
PHOTO: MICHELLE JAM
I bought an oleander plant from a nursery about three years ago. It is now about 1½ storeys tall and I have trimmed the branches several times. However, it has flowered only once, even though I add compost every three months and fertilise it monthly.
Michelle Jam
The oleander plant grows quite tall before it produces flowers. Frequent pruning can cause the plant to redirect its resources to growth elsewhere. To promote flowering, ensure the growth site is well-draining and do not over-water.
Hot weather may be cause of pumpkins' bud loss
Put up a light shade cloth to reduce heat stress.
PHOTO: THOMAS LEE
Why are my new buttercup pumpkins rotten?
Thomas Lee
First and foremost, grow pumpkin cultivars suitable for growing in the tropics. Heat stress can cause flower buds to be aborted.
Try mulching the base of the plant to keep the root zone cool and put up a light shade cloth over the plant to reduce heat stress. Also, use a fertiliser that contains calcium to assist in proper flower development.