The absorbed energy is converted to heat energy. The scenario you mention with the LED is very close to the blackbody problem known as the ultraviolet catastrophe.. There is a Wikipedia article about it here. What happens in the situation you described is that the light proof box gets hotter.
Diagnosing rust on geraniums can be a challenge for growers. Rust begins with yellow spots on the underside of the leaves and can rapidly progress with brown fungal spores called pustules in the center of each spot. The pustules are raised up off the leaf surface and feel rough to the touch.
Growth and Size. Seed geraniums are a compact version of the zonal geranium, but with smaller bloom heads, which typically measure 3 to 4 inches. Seed geraniums form a low, compact mound that is less than 1 foot tall and wide.Zonal geraniums tend to grow more upright, growing to about 18 inches in one season with large, 4- to 6-inch flower heads. Seed geraniums tend to have more numerous flowers and a more self-branching growth habit.hichever type you choose, geraniums add color to your garden. What's commonly called a geranium comes from the Pelargonium genus, which includes several species of plants, which are categorized into different types based on growth habits and propagation.