Twin Sunflower

The Twin Sunflower is an upgraded version of the Sunflower. To get it, the player must buy the Twin Sunflower seed packet from Crazy Dave's shop for $5,000.

It costs 150 Sun to plant and must be placed on an existing Sunflower.

Twin Sunflowers double the Sun production of the Sunflower, which means it increases from 25 sun approximately 24 seconds to 50 sun each 24 seconds. The increase is 25 sun per 24 seconds, and the cost for the upgrade is 150, so after about one minute and 30 seconds it has paid off. Therefore, if you will use it for more than one and a half minutes, it is worth upgrading; if not, you’ll lose sun from it.

Suburban Almanac Entry
Twin Sunflower

Twin Sunflowers give twice sun as much as a normal Sunflower.

It was a crazed night of forbidden science that brought Twin Sunflower into existence. Lightning crashed overhead, strange lights flickered, even the roaring wind seemed to hiss it's angry denial. But to no avail, Twin Sunflower was alive, ALIVE!!

Strategy
Twin Sunflowers can be used for later levels that require heavier attacking plants or abilities (Melon-pults, Gloom-shrooms, Gatling Peas). They're especially valuable in Survival Endless due to lack of space for many Sunflowers. Although Twin Sunflowers are not as efficient as Sunflowers (they produce 50 Sun every 24 seconds instead of the 100 Sun that four Sunflowers, which have an equivalent cost, could get) they take up half the space as the same amount of Sunflowers, so are more helpful for levels with large numbers of zombies that require more space for offensive plants.

Use the Umbrella Leaf to protect Twin Sunflowers, especially those in the back of the lawn, against Bungee Zombies and Catapult Zombies. However, if you have enough firepower nearby (Gloom-shrooms are most effective in this case) the Bungee Zombies should not be able to survive long enough to steal the Twin Sunflowers.

In Survival: Endless, you want at least four of these.

Trivia

 * The Twin Sunflower is one of the three plants with two heads; the others are the Split Pea and the Cherry Bomb.