Some flowering plants refuse to bloom unless conditions are ideal. Thankfully, the tropical hibiscus (Hibiscus rosa sinensis) only looks fussy and will bloom inside if given the proper care. Although hibiscus plants grown outdoors tend to bloom big — with some flowers up to 6 inches in diameter — you’ll get smaller flowers when you grow the plant in a pot indoors. Encouraging your hibiscus to bloom indoors requires giving the plant more attention than you would were you growing it outdoors. With the proper care, however, you may just have tropical flowers inside, even in winter.
Light
The number one reason why an indoor hibiscus fails to bloom is inadequate light. Sunlight not only aids the hibiscus place buds, but also gives it the capability to tolerate cooler temperatures. A sunny window is the best place for your hibiscus. If you can not supply that, artificial lights may do the job. Place the light 5 feet above the floor and let it run for 16 hours a day.
Fertilizer
To support the hibiscus to bloom indoors, use the correct fertilizer in the appropriate amount at the ideal moment. Too much nitrogen in the fertilizer will cause plenty of green foliage at the expense of blooms. Too much phosphorus can cause the buds to fall. On the flip side, the plant takes a large amount potassium to come up with flower size and colour. The ideal fertilizer is just a water-soluble formula manufactured particularly for hibiscus, or even a 7-2-7 fertilizer. The best time to feed the plant is after you water it, using the fertilizer diluted to half strength.
Water
The perfect way to tell if the hibiscus requires water would be to stick your finger into the soil up to your first knuckle. If your finger is dry, then water the plant, then slowly. Allow the surplus water to remain in the tray below the bud for 12 hours and then discard it. If the soil remains overly deep, the plant wilts and will start dropping leaf and flower buds. You’ll want to adjust the watering program according to the indoor environment, keeping an eye on the soil more frequently when it is warm inside and reducing the quantity of water supplied during cooler periods.
Pruning
A hibiscus grown in a container requires pruning to keep it to the right size and shape. Pruning, however, carries with it inherent dangers. Incorrectly pruning the plant may mean the removal of buds. The very best way to encourage new blooms is to enable new stems to grow to 2 inches in length and then pinch the tips off of them. This causes new stems to grow under the pectoral stem. Pinch the tips of these when they grow to 2 inches in length. If you duplicate the procedure throughout the growing season you’ll have flowers all year long. When shaping the plant, then use sharp pruning shears and make all cuts just above a node. New growth from these cuts should bloom in three months of pruning.