Peace lily may be lacking light
My peace lily does not seem to be thriving. The leaves are small and thin. I water it once or twice a week. Following each watering, there will be at least one healthy leaf that starts to turn yellow within two days. The pot is placed next to a window. What should I do?
Tan Poh Keam
Does the current location for your peace lily (Spathiphyllum wallisii) get at least four to six hours of filtered sunlight? Although the peace lily is a shade-tolerant plant, it should not be grown in deep shade where there is hardly any sunlight. Under dim conditions, plants do not make enough food for growth and will gradually deteriorate as described.
You may want to move the plant to a brighter location. You can also use grow lights, which are placed around 15cm from the plant and switched on for about 12 hours daily.
Plant with red leaves likely a hybrid of coleus and perilla
What is the name of this plant? Does it have medicinal value and how do I propagate it?
The plant is likely a hybrid between the coleus and perilla and its cultivar name is Gage's Shadow. Its leaves do not have the characteristic scent found in perilla leaves.
This plant is best grown under direct sunlight to maintain its red foliage and treated as an ornamental plant. It can be easily propagated via stem-cuttings.
Grow peanut plants from raw peanut fruits sold in supermarkets
There seems to be different varieties of peanuts - a wild type found by the roadside and the cultivated edible type found in HortPark and community gardens. The two seem to exhibit similar growth forms. Can they be cross-bred? How do I ascertain if the seeds sold in nurseries for growing is of the edible type and not a hybridised type that may or may not produce edible legumes?
The plant shown is mostly grown in local landscapes as a groundcover and is botanically known as Arachis pintoi. Its common name is Pinto peanut.
The common edible peanut (Arachis hypogea) tends to grow larger and taller. The Pinto peanut tends to produce creeping stems that hug closer to the ground and does not seem to produce fruit under local conditions.
Not much information can be found regarding the hybrids between the two species.
You can buy raw peanuts from the grocery section in local supermarkets if you want to grow edible peanuts. Seeds can be sown after they are taken out from the shells.
Local nurseries do not normally stock edible peanut plants in their inventories.
Wrap developing fruit to reduce damage
My four-year-old soursop tree in my garden is fruiting now. The fruit is about 3cm in diameter. Would you recommend I wrap up the fruit now to prevent it from being pecked at by birds or damaged by insects?
Beo Lan Kan
Developing fruit should be wrapped as soon as it forms to prevent damage by birds and egg-laying by fruit flies. Ideally, they should be wrapped with a plastic bag that is large enough to accommodate the ultimate size the fruit can attain. Specialised fruit bags are not commonly sold in Singapore.
Note that bags made from netted materials may not be useful as they have holes that allow fruit flies to enter to lay their eggs.
Other creatures such as squirrels may also damage the fruit. Consider creating a large cage made from chicken wire. Keep the fruit in the centre of the cage with sufficient space, so that animals such as squirrels cannot reach it.
Citrus Hindu mite infesting kaffir lime plant
I recently repotted my kaffir lime tree. White spots are appearing on the leaves. Is it due to shock from repotting or is the plant infested with pests?
Cheah Chew Ping
This issue has been addressed in previous editions of this column.
The spots on the kaffir lime leaves are caused by a tiny pest known as the citrus Hindu mite or Hindustan citrus mite. Affected leaves will not recover even after treatment.
You can use environment-friendly pesticides such as summer oil or a castile soap solution which work by suffocating the mites. Good coverage is vital. Repeated sprays of the pesticides are required to control the pest population.
• Answers by Dr Wilson Wong, an NParks-certified practising horticulturist, parks manager and ISA-certified arborist. He is the founder of Green Culture Singapore and an adjunct assistant professor (Food Science & Technology) at the National University of Singapore.
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