One of the most common causes of hibiscus blossoms falling off plants is insect pests, particularly thrips. Theses tiny insects feed on hibiscus flower buds, causing them to fall off prior to blooming. This insect lays its eggs inside the buds, turning them yellow and eventually causing them to drop.Click to see full answer. In this way, how do you keep hibiscus buds from falling off? Tips to Prevent Hibiscus Flowers From Falling Improper Watering. This is a plant that likes moist, well-drained soil, which means that even though you will want the soil to feel damp, you do not want it to be excessive. Weather – It’s Too Hot. Pests are Damaging Your Hibiscus. Over-Fertilizing Your Plant. Also, why are my hibiscus flowers not opening? This is common with hibiscuses, and is caused by stress from improper watering (not enough), too much fertilizer, extremely hot weather, or insect damage from the likes of aphids or thrips. Double flowered varieties of hibiscus seem to be particularly susceptible to bud drop. Similarly one may ask, how do I get my hibiscus to bloom? Start the plant in shade and increase the time in full sun over a period of seven to 10 days. The plant may lose some leaves as it adjusts to the outside environment. The hibiscus flowers on new wood, so your plant should eventually start to bloom as the new growth matures.How do I keep hibiscus blooming all summer? How to Keep My Hibiscus Blooming Re-pot your hibiscus in January or February of every other year. Cut the plant back by 1/3 to 1/2 in very early spring. Place the plant outdoors in late April in a location that receives full sun all day or at least for six hours. Fertilize the hibiscus every two weeks.