Spikeweed is an Area of Effect plant that attacks, dealing normal damage to all zombies that walk on it. It deals five normal damage shots in the time it takes any normal speed zombie to pass over it (faster zombies, such as the Football Zombie, can take as little as two peas worth of damage). It will also pop the tires of the first vehicle zombie that drives over it (like the Zomboni). Since the Spikeweed attacks from below, it can bypass shields.
Spikeweed is unlocked after the player beats Level 3-6. After that, the player can use Spikeweeds against the Zombonis in the next few levels. They can only be planted on the ground (not on Lily Pads or Flower Pots), which makes them useless for Roof levels. A Spikeweed can be upgraded to Spikerock after purchasing the Spikerock seed packet.
Spikeweed is unlocked after beating Pirate Seas - Day 6. It works almost the same as what it does in the first game, but does less damage at a faster rate, still doing the same amount of damage overall. There are some new zombies that can be instantly destroyed by Spikeweed such as Barrel Roller Zombie's barrel and the Pianist Zombie. Unlike the first game, it cannot be upgraded to Spikerock.
Suburban Almanac entry
Plants vs. Zombies
Spikeweeds pop tires and hurt any zombies that step on them.
Range: all zombies that walk over it
Special: can't be eaten by zombies
Hockey is Spikeweed's obsession. He's got box seat season tickets. He keeps close track of his favorite players. And he consistently cleans up in the office hockey pool. Just one problem: he's terrified of pucks.
Plants vs. Zombies 2
Sun cost: 100
Spikeweeds destroy rolling objects and hurt any zombies that step on them.
Special: can't be eaten by zombies
Weakness: crushed by rolling zombies
Although Spikeweed grew up on the seedy side of town, his acupuncture business has been blooming.
Plants vs. Zombies 2
When fed Plant Food, Spikeweed fills the row with other spikes poking up from the ground and pulls zombies to the Spikeweed for 4.5 seconds. The secondary spikes can destroy rolling items and attack zombies being drawn towards the Spikeweed. If this occurs when the Spikeweed is in a minecart, the Spikeweed may not be moved.
Note: Spikeweed can't be upgraded to level 4.
Plant Food ability can hit zombies on a jumping animation and does a small stun.
Plants vs. Zombies: All Stars
Hidden Spikes: Attacks all enemies in its row, needs Tenacious Plant Food to activate.
Plant Spikeweeds in front of Wall-nuts, Tall-nuts, or Pumpkins. Most zombies cannot harm it, and will be continuously damaged as they try to eat the defensive wall. Spikeweed is especially important for levels with Zombonis (especially in Bobsled Bonanza), and placing the Spikeweed on the first row will prevent the Zomboni from laying any ice at all (preventing the appearance of the Zombie Bobsled Team). Note that Gargantuars, Giga-gargantuars, and Jack-in-the-Box Zombies can destroy Spikeweeds in the same way as they can any other plant.
Try to lay down either a row of three Spikeweeds or one Spikeweed in front of a Wall-nut to kill the zombies. Timing can be everything, so if you see a Wall-nut, go ahead and break a few vases on the right hand side to see if a Wall-nut will be needed there. If no zombies appear closer than the fourth row from the left, put the Wall-nut on a different row, and lay down Spikeweed instead. Buckethead Zombies are the exception to this, as you cannot kill them with just Spikeweed - make sure to have a Wall-nut in place or use a Squash to kill them.
The Plant Food upgrade for Spikeweed (similar to Spikerock) can draw zombies towards it. As such, planting a Spikeweed at the rightmost side of the level and feeding it Plant Food will cause the zombie to return to the start and allow for your main offensive plants to do twice the amount of damage, assuming the zombie is tough enough. It can also be used in an emergency if any zombies get too close to your lawn mowers or as a defense against enemies thrown or able to jump over your defense.
The Plant Food-fed Spikeweed does not do a lot of damage (enough to kill a little more than a normal zombie), so do not waste your Plant Food on it unless you are using it for the "drawing-in" purposes as mentioned above. Any crushing zombies like Pianist Zombie and Barrel Roller Zombie will be destroyed but at the sacrifice of the Spikeweed. It will also stop swarms of Zombie Chickens released by the Chicken Wrangler Zombie if they get past your other plants.
Note: Using Spikeweeds on Lily Pads in Big Wave Beach is a very bad idea, as zombies will eat the Lily Pad and cause the Spikeweed to fall into the water, thus wasting 100 sun in process. Therefore, avoid bringing Spikeweeds and Spikerocks in Big Wave Beach, as the Lily Pads eaten by zombies and the Spikeweed falling into the water, thus being usually worthless.
However, it's very beneficial in the Wild West levels to use against almost all the zombies, especially with Prospector Zombie and Zombie Bull Rider which leap over your plants, so they can be good in the first column. A Spikeweed in every lane can effectively combat Zombie Chickens. Another strategy allows you to use the carts in order to keep a Wild West Gargantuar from moving ahead by moving it as soon as he lifts his hammer. In Frostbite Caves levels, it's good to place them next to any slider tiles where the zombies will shift to. If you have any plants that can push back zombies, it's useful to combine them with Spikeweed so they have to walk the gauntlet again.
- Somehow, Spikeweeds and Spikerocks damage helmets from headwear zombies, despite them hitting their feet.
- Spikeweed and its upgrade are the only plants that instantly kill some zombies but only damage others.
Specific to Plants vs. Zombies
- In the reanim folder, the Spikeweed's name is Caltrop. This may be because the Spikeweed functions like caltrops; it hurts anyone that steps on it and pops tires.
- Even though Spikeweeds cannot be planted in Flower Pots during Roof levels, Spikeweeds are always in Flower Pots in the Zen Garden. This is probably because a Spikeweed would be useless in a Flower Pot, as zombies would not walk over it, but they do not need to attack any zombies in the Zen Garden. The Spikeweed is actually too wide for its Flower Pot, and sticks out over the sides, like an armed Potato Mine.
- Spikeweeds and Spikerocks have a faster attack rate than other plants.
- When a Spikeweed is planted in one of the two bottom right squares on Pool and Fog Levels, it will be higher up than other Spikeweeds.
- Jack-in-the-Box Zombie, Zomboni, Catapult Zombie, Bungee Zombie, Gargantuar, Giga-gargantuar, and Jalapeno Zombie are the only zombies that can destroy Spikeweeds and Spikerocks.
- Alone, it takes two Spikeweeds to destroy a regular Zombie.
- When a Zomboni hits a Spikeweed and then a Squash tries to squash it, the Zomboni will not explode when the Squash squashes it. That is because the Zomboni is already killed after hitting the Spikeweed, so the Squash will not affect it.
- It is unknown how Spikeweed can make the Zomboni's ice machine or the Catapult Zombie's catapult machine explode by just popping the tires, although Spikeweed may degrade their health to zero. If they do not explode, it would not make sense, since the zombies cannot escape and leave the vehicle on the lawn, the spikes of the Spikeweed and Spikerock may have damaged parts other than the tires, causing the vehicle to explode.
- Spikeweed is one of the twelve plants that appear in the seed selection screen after the player gets Grave Buster on the online version, the others being Ice-shroom, Lily Pad, Potato Mine, Threepeater, Tangle Kelp, Jalapeno, Doom-shroom, Torchwood, Tall-nut, Cactus, and Blover.
- Spikeweed's flavor text about hockey seems to be in line with its role of destroying Zombonis (a vehicle with a close link to hockey itself) and its main role in the Vasebreaker level Hokey Pokey.
- If the player looks closely, the Spikeweed's eye pupils are red.
- Spikeweed and Spikerock are the only multi-use plants that cannot be eaten.
- Spikeweed, Spikerock, Fume-shroom, and Gloom-shroom are the only plants that attack every zombie within their attack range with the same damage to each.
- It is unknown why in I, Zombie, Crazy Dave made a cardboard Spikeweed when it cannot be eaten by zombies, although this may be because it can be destroyed or stolen.
- The color of Spikeweed's plant part looks like mud.
- Spikeweed, Spikerock, Lily Pad, Cattail, Tangle Kelp, and Sea-shroom are the only plants that cannot be planted on a Flower Pot.
- Spikeweed, Spikerock, Flower Pot, Tangle Kelp, Sea-shroom, and Potato Mine are the only plants that cannot be planted on a Lily Pad.
- In Vasebreaker, Spikeweed only appears in Hokey Pokey.
- It is possible to destroy two or more vehicles with a single Spikeweed. However, those vehicles must ride over the Spikeweed both at the same time.
Specific to Plants vs. Zombies 2
- If the player unlocked Spikeweed's costume and uses its Plant Food ability, its costume will disappear for the duration of the Plant Food effect.
- Spikeweed now attacks twice a second, but does 0.5 damage for each attack.
- Unlike the first game, Spikeweed's color is changed to green instead of brown.
- If the player uses Plant Food on a Spikeweed, all the Barrel Roller Zombies or Pianist Zombies on the lane will not be instantly destroyed, but instead, the plant damages them. This trait is shared with the Spikerock.
- It is one of the few plants in that has a job outside the game, as stated in the Almanac.
- Spikeweed's costume resembles Groucho Marx.
- Spikeweed's sound when damaging zombies has changed to a sound like air being leaked out of a bag.
- If a Spikeweed is planted under a barrel without a Barrel Roller Zombie pushing it, it does not destroy the barrel, and will simply keep attacking the barrel until it's destroyed.
- Spikeweed cannot pop Shield Zombie's treads.
- Spikeweed's Plant Food ability also affects the Zombot Plank Walker, and causes him to pause until it is over, which will cause him to jump back to where he was.
- Spikeweed's costume in the Chinese version affects the Plant Food effect, the duration of the Spikeweed pulling the zombies is longer and when a zombie hits the Spikeweed it will spin and become dizzy and walk backwards, like a Hypno-shroom, it hypnotizes the zombies.
- Spikeweeds can now be planted on Lily Pads. However, doing so, when a zombie tries to eat it, it will eat the Lily Pad instead, losing Spikeweed and wasting 125 sun in the process.
- It can instantly destroy pianos, despite the fact they do not have any visible wheels.
Specific to Plants vs. Zombies: All Stars
- It attacks zombies that are close to it by going underground and spinning on the tile in front of it.