Let soil dry out between watering succulents
When I bought these succulents, I was advised to sprinkle them with water once a week. When the weather became hotter, I was supposed to sprinkle water on them twice a week. However, the bigger succulent now looks like it is stressed (below) and has released some liquid from its leaves. What happened? How should I care for succulents?
The larger succulent is likely to be a species of Pachyphytum, while the plant in the smaller pot is likely to be a species of Echeveria.
These plants are generally more challenging to grow as they prefer a cooler and drier environment with a temperature drop at night to thrive.
Without such conditions, the plants are stressed and prone to various pests and diseases.
Prolonged wetness will lead to rot and subsequent death of the plant, as shown in your picture.
It is better to change the soil and grow succulents in a well-drained mix consisting of fine, expanded clay pellets, pumice and volcanic sand.
After watering the plant, allow the media to dry out before the next watering.
Also, place the succulents in a sheltered area and out of rain. Exposing them to filtered sunlight will keep them compact.
Tip: Attractive Herringbone Plant a good houseplant
The Herringbone Plant was commonly cultivated a few years ago. This cultivar (above) is botanically known as Maranta leuconeura var. leuconeura "Fascinator".
This plant has attractive foliage - red veins and a yellow midrib contrast against a dark green background. The leaves are also thicker and larger, which make the plant resilient and easier to grow.
It grows like a creeper and thrives best when it has moist, well- drained soil and gets filtered sunlight.
It makes for a good houseplant. However, keep it away from an overly windy location where it can dry out.
Gall wasps cause leaf bumps
The new leaves at the top of my plant curl up and have bumps. The leaves farther down the plant are fine. What is wrong?
The tree is commonly known as the Coral Tree and its botanical name is Erythrina fusca. It is rarely planted in Singapore because it has a pest issue.
The adult female Erythrina gall wasp lays its eggs in the plant's young leaves and petioles, which are stalks that join a leaf to a stem. The larvae that hatch in the plant's tissue will induce the formation of galls.
To reduce the incidence of the pest infestation, apply a systemic pesticide periodically in the soil around the tree's root zone. The pesticide will be absorbed by the plant through its tissue and kill the insects.
Sabah Snake Grass used in folk medicine
What is this plant and can its flowers be eaten?
Lim Kok Leong
Commonly known as the Sabah Snake Grass, this is a shrub that belongs to the Acanthaceae family. Its botanical name is Clinacanthus nutans.
It is often planted in medicinal gardens and used in folk medicine to treat illnesses such as cancer.
Its dried leaves can be made into a tea while its fresh leaves can be blended into juice for medicinal purposes.
However, consult a certified practitioner before attempting to use this plant to treat any health issues.
Lavender needs well-drained mix
Can I grow lavender in Singapore? What other scented plants can I grow besides jasmine?
It is possible to grow lavender from seeds, but it is easier to buy potted lavender plants from large local nurseries here.
However, the potted plants here are often raised in a moisture- retentive growing media.
Plants left in this media often decline over time because of Singapore's overly moist and humid climate. Some plants come from the Mediterranean climate, which is drier and, at times, cooler.
To ensure that your lavender plant has a higher chance of survival, take stem-cuttings from the original pot and root them in coarse aquarium gravel. The rooted cuttings can then be planted in a well-drained mix made up of burnt earth, pumice and other gritty materials.
The plants should get at least four hours of direct sunlight and should be shielded from the rain.
Lavender plants can flower in Singapore, but die easily during the cloudy and wet season.
Other fragrant shrubs that can be grown more easily include sweet almond bush, dwarf ylang ylang, "Min-A- Min" murraya and shui mei (Wrightia religiosa).
These shrubs are best planted in the ground outdoors in well- drained soil and under direct sunlight.
•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.
•Have a gardening query? E-mail it with clear, high-resolution pictures of at least 1MB, if any, and your full name to firstname.lastname@example.org.