Solar Flare Beam

Not to be confused with Solar Flare from Plants vs. Zombies Heroes.

Solar Flare Beam is an alternate ability of Sunbeam. It is more powerful, which deals 10 impact damage and 12 critical damage, but it only has 50 ammunition, and it does not instantly fire after pressing fire button. Like most of the other alternate abilities, it was first introduced in the Garden Variety DLC. It takes 30 seconds to recharge.

Stickerbook description

The Solar Flare Beam is now the ultimate power in the universe! We suggest you use it.

Strategies

With

Even though this ability can deal more damage, it should only be activated in certain places where enemies will not notice something is coming while trying to do their task (e.g. capturing the garden and taking out the other plants etc.).
Be careful in Garden Ops or Gardens & Graveyards, as this ability will alert the Spawnable Zombies to your team's location. When the zombie is not moving, shoot immediately at them.
Avoid using this ability in open spaces, as you will be exposed and you can get shot at from any direction. If you use this in an open spot, don't shoot, then unroot and find a better place.
Try having another Sunflower nearby or a Heal Flower in a safe spot to heal yourself if a zombie tries attacking you.

Against

If fighting close up, try moving around the Sunflower whilst shooting, which makes it difficult to aim for many Sunflowers due to the fact that the turning is not fast.
Scientists must remain mobile both by moving and by using the Warp/Energy Warp ability. Take the Sunflower out early whilst staying close to kill it as quickly as possible.
All-Stars are vulnerable to this ability due to their speed. Set up Dummy Shields/Shield Decoys/Future Dummy and use an Imp Punt or Long Bomb to vanquish the Sunflower quickly.

Comparison to vanilla counterpart

Pros

Higher damage.

Neutral

Fire button needs to be held down which although might make your attack too late, is also good for last minute decisions (and saving the beam for another situation).

Cons

Low ammo.
Beam is easier to see than the Sunbeam.

Gallery

Garden Warfare

Garden Warfare 2

Trivia

Even though the icon shows the Sunflower's eyes glowing, they do not glow when actually using the ability.
Its firing visuals and description reference the Death Star from Star Wars.
Its name is also a possible reference to the technique that is used in the Dragon Ball Series.
The Solar Flare Beam is green rather than yellow, like the Sunbeam.