Artificial light can help plants grow, but too much light of any kind can be harmful. The best way to use solar lights is to place them in an area where they will not be directly shining on the leaves of plants. During the winter when there is very little light from the sun, this can affect the growth of plants. Having garden lights using artificial light to provide a light source will be beneficial for the plant's flowering and growth. If you have a greenhouse then solar greenhouse lights would be a great option. These are designed to emit light that helps plants grow even during the winter months.