Question: Why do the flower buds of my potted hibiscus plant fall off before they can bloom? It is placed under direct sunlight with daily watering and I have tried using different kind of fertilizers from used coffee powder, GardenWell Merah 46 and seaweed liquid fertiliser. - Denmy Answer: The potted hibiscus may be suffering from heat stress. It may be good to re-pot it into a larger pot with soil that is enriched with organic matter and provide some shade (filtered sunlight) to provide the plant with a cooler growing environment. Avoid heavy dosing of fertiliser when buds are forming. Shock can lead to abortion of flower buds, too. Also avoid irregular fluctuations in the growing environment and regime. Hibiscus in bud are well known to react quite badly to changes in growing environment. - Dr Wilson Wong Ask the Expert team is made up of NParks horticultural and gardening experts. If you have any questions on plants or plant-related subjects, please send your question to Ask the Experts at nparks_communications@nparks.gov.sg Photo of hibiscus by Vicky Lim.