Plant lettuce in a more shady location and cucumber, tomato, pepper, and eggplant in a sunny spot. At least 4 hours of direct sunshine is needed in summer. Indoor locations are not suitable in summer because they do not receive direct sunlight. Indirect light does not furnish enough energy for growth. Look for these signs of low light.
Plants become leggy.
Many plants, like cucumber, squash and pepper will drop blooms and fail to set fruit. Others, like tomato, will fail to form many blossoms. If you observe these signs, gradually move the container to a sunny location. Rapid change may result in sunscald. Providing artificial lighting of vegetables is expensive and should be used only as a novelty.