Sun producing plants are plants that generate sun over time when planted; the more on the lawn, the more sun will be generated.
Sun producing plants include Sunflower, Sun-shroom, Twin Sunflower, Primal Sunflower, Moonflower, Power Flower, Sun Bean and Giant Sunflower. These are often placed on the back of the lawn, far away from approaching zombies except for Sun Bean, Toadstool and possibly Gold Leaf. They must be planted at the start of a level; without them, the player will be able to plant very few to no offensive plants (save from Puff-shrooms, Sea-shrooms, Iceberg Lettuces and Stallias), which will quickly lead to the player's defeat.
Unlike other sun producing plants, Sun Bean does not directly produce sun and instead causes zombies to drop sun. After a zombie eats a Sun Bean, it will drop very small sun, which is worth five sun for every normal damage shot. The zombie will faintly glow yellow and white to indicate that it is affected by a Sun Bean.
In Plants vs. Zombies, the main differences between Sunflowers and Sun-shrooms are that Sunflowers will always produce 25 sun per 24 seconds, while Sun-shrooms will produce 15 sun at first, but after two minutes, it will start to produce 25 sun. The other difference is that the Sun-shroom is a nocturnal plant, so it is not a very good idea to use them on daytime levels.
In Plants vs. Zombies 2, Sunflowers produce 50 sun while Sun-shrooms produce 25 sun at the beginning, 50 sun after their first growth and 75 sun after their final growth.
When a sun producer is first planted, it will take approximately seven seconds to generate its first sun, but after that it will take 24 seconds for every other sun.
Sun-producing plants cannot be used in all levels related to Last Stand and Sun Bombs series. High amount of sun producing plants is required to pass some Brain Busters in which a set quantity of sun needs to be produced in the duration of the level to pass it.