Twin Sunflower

The Twin Sunflower is the upgrade for the Sunflower. To get it, the player must buy its seed packet from Crazy Dave's Twiddydinkies for $5,000, same as Gatling Pea. It appears on sale after beating level 3-4, with the Gatling Pea. It is available as soon as Crazy Dave's Twiddydinkies is open. It costs 150 Sun to plant and must be placed on an existing Sunflower. Twin Sunflower double the Sun production of the Sunflower, which means it increases from 25 sun approximately 24 seconds to 50 Sun over the same amount of time. The increase is 25 sun per production, and the cost for the upgrade is 150, so after about 144 seconds it has paid off. Therefore, if you will use it for more than two and a half minutes, it is worth upgrading; if not, you will lose Sun from it which can be very bad, sometimes critical.

Almanac Entry
Twin Sunflower

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

Sun production: double

Must be planted on sunflowers

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

Cost: 150

Recharge: very slow

Strategy
Twin Sunflowers can be used for later and longer levels that require heavier attacking plants or abilities. They're especially valuable in Survival Mode due to lack of space for many Sunflowers. Although Twin Sunflowers are not as efficient as Sunflowers, they take up half the space as Sunflowers producing the same amount of Sun, 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 the Bungee Zombies and Catapult Zombies. However, if you have enough firepower nearby, the Bungee Zombies should not be able to survive long enough to steal the Twin Sunflowers.

In Survival Mode, you'll want at least five or six of these so that you can build up your defense quickly.

Flower Power Achievement
If you plant 10 Twin Sunflowers and keep them alive, you will earn the Flower Power Achievement. The easiest way is to get the achievement is to play a easy level. Play a Survival Level (not Endless), preferably Survival: Pool, (due to it being a level in the daytime that has six rows) and plant Sunflowers to be upgraded to Twin Sunflowers. It is recommended that you protect them with Pumpkins and Umbrella Leaves. Replace the Pumpkins when and if needed. Of course, use your usual Survival strategy for that level. All 10 Twin Sunflowers should make through to the end. Or you can play ZomBotany 2, because there are three flags. It's better to use six Gloom-shrooms and two Garlics and then keep 10 Twin Sunflowers to alive and don't let them get shot down by peas.

Trivia

 * The Twin Sunflower is one of the three plants with two heads; the others are the Split Pea and the Cherry Bomb, although the Split Pea's second head is not a head, but merely a head-like growth as it is stated in the Suburban Almanac Entry.
 * The Twin Sunflower has three leaves that look like hands, unlike the Sunflower, which has none.
 * This may be a reference where some flowers have edgy leaves.
 * When planted, the screen darkens for an instant, reminiscent of the lightning mentioned in the Suburban Almanac description, however it is unknown if this is a glitch or not.
 * Apparently, the Twin Sunflower was made in a laboratory.
 * It is very useful in Survival: Endless.
 * The Twin Sunflower and Gatling Pea are the two Upgrade Plants that cost $5,000 (the 2nd lowest), the lowest being the Gold Magnet, at $3,000.
 * The Twin Sunflower does not glow before producing sun on the DS version.
 * The Twin Sunflower is the only two-headed plant with the only Suburban Almanac Entry with none of them talking.
 * The Twin Sunflower, the Sunflower, the Puff-shroom, the Sun-shroom and the Sea-shroom are the only plants not allowed to be used in Last Stand.
 * The Twin Sunflower and Gatling Pea are the first two upgrade plants in Crazy Dave's Twiddydinkies.
 * Twin Sunflower is often used to save space. For example, 10 Sunflowers can be compressed into 5 squares with Twin Sunflowers.
 * This, along with the Sunflower, Sun-shroom, Flower Pot, Lily Pad, Plantern, Marigold, Coffee Bean, and Gold Magnet have neither offensive nor defensive capabilities.
 * The Twin Sunflower is the only Upgrade Plant in Plants vs. Zombies that appears in Plants vs. Zombies Adventures.