Potpourri

Potpourri is an instant-use, zombie-modifying plant that both strengthens and slows every zombie on the field.

Overview
Being an instant-use plant, Potpourri activates when planted. She'll douse the entire field in a pink aromatic perfume. This doubles the health of every normal zombie affected, and increases the health of any Gargantuar-esque zombies by 50%.

On the flip side, every zombie affected is heavily slowed. Normal zombies have their speed halved, and Gargantuar-esque zombies get their speed slowed by a quarter.

Potpourris stack with each use, though zombies have a cap on their increases or decreases health and speed.

Poisoned zombies (or plants) will have their poison cured.

Potpourri's effects can be removed when they go into the water, or are hit by a water attack.

Slowed zombies can still be slowed down by Sap-fling, Snow Pea, etc. and vice-versa.

Hypnotized or possessed zombies will receive the health boost, but not the speed debuff.

Potpourri is based off of the material of the same name, which is made up of dried fruits and other plant parts.

Strategy
Potpourri can be easily described as a double-edged sword. Try to avoid using Potpourri when you don't have a decent defense and offense up, as they could chomp through a weak enough barrier to get to your house. Try to also avoid using her when zombies are close to your house, as then they'll be harder to kill, putting you in danger.

Due to her curing effect, it is heavily advised to not use Potpourri with Shadow-shroom, Manchinill, or other poisonous plants.

Otherwise, Potpourri works well with Spikeweed and similar plants, as zombies'll take longer to traverse the damaging area. Slowed zombies will also take longer to actually pose a threat to any valuable plants you may have deployed.

Trivia

 * Potpourri's almanac entry and curing ability are both references to (plague) doctors stuffing potpourri into their masks to prevent illnesses from entering their bodies during the seventeenth to nineteenth centuries.
 * Potpourri could be seen as a counterpart to Fleur-de-Lis.
 * Both plants cover the board in something that boosts health, with Potpourri affecting zombies and Fleur-de-Lis affecting plants.