I bought a 1 1/2 foot yellow Hibiscus from Home Depot yesterday and it had beautiful, healthy looking flowers on it when I brought it home. We transplanted it into a large pot with new soil and watered it, and the flowers closed up at night as expected. However, they never opened back up the next morning despite being in full morning sun for about 5 hours. They are still closed and I'm not sure what to do to get them to open back up.
Certified GKH Gardening Expert
The hibiscus flower normally blooms for only one day, opening in the morning and wilting by late afternoon. To compensate for this, the buds grow quickly and are opening all the time, sometimes producing more than a hundred blooms in a season. Be patient, as more buds will open and replace the ones from the previous day. Therefore, it is normal. However, if you have a lack of buds or flowering, you can add a bloom plus fertilizer or bone meal to the soil around your plant to add additional phosphorus, which is responsible for blooming in plants. If you are noticing any flowers or buds that are falling off, or buds that simply do not open, this could signal a problem. If that were the case, this article would be of some help: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-flowers-hibiscus-blossoms-falling-off-plant.htm