Yes, the bird of paradise sun requirements are high compared to most houseplants. The NYBG recommends a minimum of 3-4 hours of direct sun each day for healthy growth. Push that to 6 hours if you want any chance of blooms, per Garden Design. This plant evolved under the intense South African sun and it still craves that bright light indoors.
I learned just how much bird of paradise light needs matter when I kept two identical plants in different rooms. The one sitting in my south-facing window grew five new leaves over one summer and kept a deep, rich green color. The other plant in an east-facing bedroom grew only two leaves and they came in lighter and thinner. Same watering schedule, same soil, same fertilizer. The only difference was the light each plant received.
Indoor bird of paradise light needs are harder to meet than most people expect. Glass windows filter out a portion of the sun's energy, and light drops off fast as you move away from the pane. A spot 6 feet from a window might look bright to your eyes but delivers only a small fraction of the light that hits the glass. Place your plant within 3 feet of the window for the strongest results.
Outdoors, the picture gets interesting. UF IFAS research found that partial shade can produce taller growth and even larger flowers on bird of paradise plants. This sounds like the plant doesn't need full sun, but the key detail matters: you still need full sun to trigger blooming in the first place. The UW-Madison Extension backs this up. Too little light is the top reason mature plants refuse to flower. A plant in heavy shade will grow leaves just fine but never send up a bloom spike.
Your plant will tell you when it isn't getting enough light. Watch for long stretches of bare stem between leaves, which signals the plant is reaching for more sun. Leaves that come in pale green or yellowish despite proper watering point straight to a light problem. A plant that leans hard toward the window is another clear sign. Rotate the pot a quarter turn every week to keep growth balanced.
During winter months, natural daylight hours shrink below what this plant needs in most of the country. A full-spectrum grow light running on a timer for 6-8 hours per day fills the gap well. I first added a grow light to my setup in November. My plant pushed out a new leaf by January, which had never happened in winter before. Set the light about 12-18 inches above your plant for the best coverage.
Bird of paradise direct sunlight tolerance is strong, but watch out for sudden changes. Moving a plant from a dim corner straight into harsh afternoon sun can scorch the leaves. Introduce more light over 7-10 days by increasing exposure a couple of hours at a time. Once your plant adjusts, it handles full bird of paradise direct sunlight with no burns at all. You'll see the fastest growth and densest foliage once it gets all the sun it wants.
Read the full article: Bird of Paradise Plant: Care and Growing Guide
