Ruebarb

Ruebarbs are plant-modifiers that deal damage once the plant they affect is eaten.

Overview
Ruebarb cannot be planted on its own. Instead, it needs to be planted on another plant. Doing so causes that plant to gain a redder hue. Once that plant is eaten, or is destroyed by any other means, then Ruebarb will cause damage in a 3x3 area.

The amount of damage Ruebarb deals is dependent on an infected plant's health and sun-cost, though the damage dealt on the outside 9 squares will always be less than the damage dealt on the tile of the plant. The damages that can be done are: Note that if a plant's health causes it to deal more damage than its sun-cost, then Ruebarb will deal damage relating to the plant's health. Otherwise, the plant's sun-cost takes priority.
 * Plants that cost 500-425 sun, or have double Gargantuar-Smashes health (as in, the amount of health they have is more than that of a Gargantuar's smash) - 100 damage on tile, 50 damage around.
 * Plants that cost 400-325 sun, or have Tall-nut-like health - 80 damage on tile, 40 damage around.
 * Plants that cost 300-225 sun, or have higher than Wall-nut health - 60 damage on tile, 30 damage around.
 * Plants that cost 200-125 sun, or have around Wall-nut's health (including Wall-nut itself) - 40 damage on tile, 20 damage around.
 * Plants that cost 100-25 sun, or have regular health - 20 damage on tile, 10 damage around.
 * Plants that cost 0 sun - 5 damage on tile, 3 damage around.

Ruebarb is based off of the Rheum rhabarbarum, also known as rhubarb. Its name is a portmanteau of "rue" and "rhubarb."

Plant Food Ability
Ruebarb does not have a Plant Food ability.

Strategies
Use Ruebarb on your defensive walls, as these are most likely to get eaten, and you will be able to severely damage the zombies that got past your defenses. The high-cost plants, such as Banana Launchers, Coconut Cannons, and Winter Melons are also good candidates, though these are most likely situated away from harm or danger.

Don't use Ruebarb on plants such as Puff-shroom or Stallia, expecting to be able to do damage for a cheap cost, as the actual damage dealt will be small, and it won't be worth the recharge of Ruebarb.