Homing Thistle

Homing Thistle is a premium plant that was released in the 2.9.1 update of Plants vs. Zombies 2: It's About Time. It attacks similarly to the Cattail. Cattail shoots two spikes, but each spike is only one damage per shot. However, Homing Thistle shoots one thistle instead of two but each thistle deals two normal damage shots. Like Ghost Pepper and Sweet Potato, it costs 109 gems instead of real money.

Almanac entry
DAMAGE: Moderate

RECHARGE: Mediocre

Homing Thistles fire seeking shots at targets that are closest to home.

Range: anywhere on lawn

Don't even think about trying to pull one over on Homing Thistle. He's got a bead on you. He sees right through your facade. It's like he has a laser beam ... aimed at your soul.

Plant Food upgrade
When given Plant Food, Homing Thistle shoots many glowing blue projectiles that target zombies on the screen, or tombstones, if there are not enough zombies. The blue projectiles do more damage than normal ones, and they sometimes encircle zombies for a long period of time. If there are no zombies present on the screen, Homing Thistle will fire the projectiles in a spiral shape.

Strategies
The Homing Thistle, in groups, can thin out the ranks of lesser zombies very quickly and pile on damage on single targets, making them a good compliment to any offensive. Their flying thistles can target just about any enemy type from anywhere, including Snorkel Zombies while they are swimming, Prospector Zombies after they have jumped, and even Swashbuckler Zombies while they are swinging (the thistles will wait in ambush where they will land). Since they always target the enemy closest to the Lawn Mowers first, enemies closing in on the Player's House can expect to take additional damage even if their row is unoccupied.

The Homing Thistle however requires mass planting for them to be effective by themselves, as groups of enemies with high toughness (such as Buckethead Zombies) can tank through a storm of thistles. This is complicated by their slow recharge time and, ironically, their priority on targets furthest ahead on the lawn, which often causes them to target lesser enemies while ignoring real threats like Buckethead Zombies, or especially high-level enemies such as Gargantuars or Wizard Zombies. If the player is using them exclusively as their only offense, it's best to support them with defensive plants such as Spikerock and Tall-nuts, while using plants such as Cherry Bombs, Chili Beans, Iceberg Lettuce, and similar plants to stall or pick off higher-level enemies.

Trivia

 * It first appeared in the shop on November 5, 2014.
 * Its name is a pun on Homing Missile Combined with a real life plant, thistle.
 * This, Power Lily, Pea-nut, Ghost Pepper, and Sweet Potato are currently the only premium plants that do not appear in Plants vs. Zombies.
 * Homing Thistle is the only plant so far to have two different Plant Food effect animations.
 * It is based on the Onopordum acanthium, a species of thistle and an ancient Celtic symbol.
 * It prioritizes zombies over gravestones.
 * It can target submerged Snorkel Zombies.
 * If a Swashbuckler Zombie has not yet landed, the Homing Thistle's needles will circle around the tile it will land on until it touches ground.
 * If the player puts Plant Food on it after final wave, it will shoot normal projectiles instead of the blue glowing ones.
 * This and Spikerock are the only plants that have a sun cost of 250. However the Tile Turnip will cost 250 sun if one is planted already.
 * This is currently the only premium plant purchasable with gems not to be available for a limited time.
 * It and (by technically) Pea-nut are the only Projectile-shooting plants to have a mediocre recharge speed.