Morning glories naturally close their flowers later in the day as part of their daily cycle. This behavior helps conserve energy and attract pollinators during optimal hours. Environmental factors such as temperature fluctuations, lack of sufficient sunlight, or inadequate watering can also cause the flowers to wilt prematurely. Ensuring that your morning glories receive full sun and consistent moisture will help maintain their health and prolong the display of their beautiful flowers. Additionally, providing proper support for their growth can prevent stress on the plants.