Indian Borage may help soothe the throat
I was given this plant which has furry leaves. Its stems are said to have medicinal properties, but I am not sure what they are. What is its name and what can I use it for?
The plant is commonly known as Plectranthus amboinicus. Its common name is Indian Borage and it is a member of the mint family, Lamiaceae.
It is commonly mistaken for the common mint plant.
Sometimes, it is used as a substitute for oregano, so you might also hear it being called by its other common name, Cuban Oregano. Locally, this plant is used to treat coughs - the leaves are boiled and the resultant decoction is drunk to soothe the throat.
Wet compost heap deters earthworms
I have tried composting by burying fruit peel, egg shells and vegetables in soil under a shed, but I get a lot of small cockroaches with shorter feelers instead of earthworms. How do I get rid of the cockroaches and prevent them from multiplying in my garden?
Yong Mei Lan
Without a picture of the insects, it can be difficult to identify what they are. Those cockroach-like insects could be wood lice or springtails. They are attracted to the decomposing materials and are usually part of the decomposition process that is involved in compost-making.
From the list of materials, you appear to be adding a lot of "greens", which make the compost pile a wet one. The lack of air spaces due to excessive moisture could be a factor that deters earthworms from inhabiting the pile.
You may want to include some "browns", such as newspapers, shredded dried leaves and small twigs - these will add more carbon and lead to a less wet mix. Together, these will promote a more healthy decomposition process. Also, avoid adding too much acidic materials such as citrus peels.
Tip: Ornamental Cassava has edible leaves and tubers
Shown in the picture on the left is an ornamental, variegated Cassava plant. Its botanical name is Manihot esculenta "Variegata".
It is a highly attractive plant that should be considered for planting in an edible plant garden.
The variegated leaves add colour to a largely green productive plot.
This plant produces leaves and underground tubers which are edible, but they may not be as tasty as cultivars that are grown specially for their edible foliage and tubers.
It propagates easily from stem- cuttings and must be grown in full sun for healthy and robust growth.
Chemical pesticide necessary to manage pests
My Cycas Palm is covered with white growth. It spreads quickly, causing the stems and leaves to be covered with pests. What type of insecticide can I use?
The plant is likely to be affected by scale insects, a type of sucking insect pest. It appears that the plant is badly infested. In this case, it is advisable to use a chemical pesticide such as cypermethrin.
Ensure that you cover all parts of the plant thoroughly. It is necessary to repeat applications at least once a week to control the infestation.
You may also need to switch pesticides to prevent the development of pesticide resistance in pests.
When applying chemical pesticides, wear appropriate protective gear and keep young children and pets, especially fish, away from sprayed plants.
Follow the label instructions on how to make the pesticide solution. Avoid using too much as this can damage the plant.
Finally, ensure that your plant is getting sufficient sunlight for healthy growth. A plant that is exposed to excessive shade and/or drought can result in pest infestations.
Grow roses first on sheets of moist tissue paper
I bought two packets of rose seed. One is multi-coloured while the other is dark purple. Based on what I've found on the Internet, there are many ways of planting the seeds, such as putting them on a piece of moist tissue and storing them in the freezer. What is the best way to grow them in tropical Singapore?
Md Shaheedu B.P. Md
First, ensure that you get seeds from a reputable source that guarantees the rate of germination and cultivar stated.
Next, put the seeds between sheets of moist tissue paper housed inside a translucent disposable food container - this allows for a more sterile environment compared with sowing them in soil. Such a set-up also lets you monitor the progress.
The tissue paper should feel moist and not be dripping wet. Add some water when necessary to ensure the sheets remain moist and are not dried out.
Once the seeds start to germinate, you can carefully remove them and sow them in potting mix.
Putting the seeds in a freezer may be too cold.
Some sources mentioned that some rose cultivars require a stratification process which involves putting the seeds in the chiller section of the refrigerator (about 4 deg C), which is less cold compared with the freezer, for several weeks.
• Answers by Dr Wilson Wong, a certified practising horticulturist and founder of Green Culture Singapore (www.greenculturesg. com). He is also an NParks-certified park manager.
• Got a gardening query? E-mail it with clear, high-resolution pictures, if any, and your full name to firstname.lastname@example.org