Hello, and welcome to another PvZ Math blog! Here, I'll be using math to try and work out the most powerful boosted plants! Not all plants are going to be shown here, but I'll try to include as many as possible.
So the Sun Producers all have PF effects that produce extra sun. But which is best overall?
Sunflower: Produces 150 sun. If used as a boost, this means every Sunflower will instantly give you a profit of 100 sun, 125 if you dig it up with a 50% shovel refund immediately afterwards.
Twin Sunflower: Produces 250 sun. If used as a boost, this means every Twin will instantly give you a profit of 125 sun, or 185 if you dig it up with a 50% shovel refund. However, due to the recharge timer being around three times as long as a Sunflower, you can actually produce sun quicker with a regular Sunflower boost than with a Twin Sunflower boost.
Sun-shroom: Grows to full size, and produces 225 sun. Instant 200 sun profit, 210 if you dig it up with a 50% shovel refund. However, digging it up isn't worth it, as it now produces 75 sun at a time normally, instead of 25, then 50, then 75.
Sun Bean: Yes, I'm counting it as a sun producer, even though Sun Bombs doesn't for some reason. Sun Bean's Plant Food is difficult to compare due to the fact that the amount of sun produced is highly dependant on which zombie eats it. It can range from producing 60 sun or less (regular zombie, or badly damaged zombie) to around 750 sun (Robo-Cone, the strongest zombie that's affected), plus instant-killing a zombie. It's the best boost out of the sun producers if you can use it on zombies like Buckets, Knights and Robo-Cones consistently, but otherwise, it's not worth it.
So the victorious plant here is, depending on the situation, either Sun-shroom or Sun Bean!
The Peashooting plants have purely offensive PF effects, and so how effective the boosts are would depend largely on how many zombies are in the plant's range to attack.
Peashooter: For 100 sun, it causes 60 instant damage. That's about 1.6 sun per pea of damage.
Repeater: For 200 sun, it causes 120 instant damage. That's the same sun-per-damage, but the last pea may waste some damage if it hits a weak zombie. Then again, Repeater's boost can dish out damage quicker than Peashooter since it has the same recharge but more damage per boost, so if you're digging up and replacing it, it can be more effective.
Threepeater: For 300 sun, it causes up to 180 instant damage. However, the inaccuracy of most peas it fires means much damage is wasted and so it's usually an ineffective boost.
Split Pea: For 125 sun, it causes up to 180 instant damage, 60 forwards, 120 backwards. If planted in the middle of a crowd, this can be highly effective and have no wasted damage, aside from perhaps the large pea if it hits a weak zombie. As such, it can deals one damage for every 0.694 sun you spend, more than twice as effective as Peashooter. Unfortunately, utilizing it like this means it has no longevity and is just an instant-use plant really, and should be dug up immediately after the PF wears off.
Pea Pod: For 125 sun, it causes about 100 instant damage. That's 1.25 sun per pea of damage. Unfortunately, it can only hit up to five zombies, and so it's almost always got a large amount of wasted damage, and is practically useless against Chickens or other crowds.
Snow Pea: For 150 sun, it slows the whole row and causes 60 instant damage. That's not much better than Peashooter in all honesty.
Pea-nut: For 150 sun, it causes 60 instant damage and gains armour. Meh.
Overall, the best Peashooting Boost is Split Pea, if used correctly.
Any plants that cause an effect to the whole entire screen, affecting basically every zombie everywhere.
Cabbage-pult: 10 damage to every zombie, for 100 sun. Better than Peashooter, but not particularly good.
Iceberg Lettuce: Freezes every zombie for ten seconds for ZERO sun. With Imitater, this boost can be used to infinitely stall any zombies that are affected, and without, it's still capable of massive stalling tactics.
Kernel-pult: Two damage and five-second stunning to every zombie for 100 sun. Ineffective compared to Cabbage-pult and Iceberg Lettuce.
Spring Bean: In Pirate Seas, it can likely insta-kill almost everything. Elsewhere, it requires a Blover to do that. And I'm talking about the boost alone, so overall, Spring Bean is only useful in Pirate Seas, and in certain levels, even then it isn't much good.
Melon-pult/Winter Melon: Both are about equal. Around 10 damage to every zombie onscreen, plus light splash meaning that grouped up zombies can take additional damage. Winter Melon's additional slowing likely isn't going to do much as most zombies will already be slowed.
Magnet-shroom: Debuffs all metal-users for 100 sun, and then causes massive amounts of damage to zombies in the row. Effective dependant on situation, only when many metal objects are available, and usually the more metal objects there are, the more zombies there are in the row, nullifying much of the power of its attack.
I'd say the winner of this is Iceberg Lettuce, by a long shot.
For assorted PF effects that only hit one lane, but usually hit the whole lane.
Spikeweed/Spikerock: Causes heavy damage to the lane, and pulls zombies towards it, all for only 100 sun (or 250 for Spikerock). Spikeweed boost is definitely better because if there's a damage difference, it's hardly noticable. Also instantly breaks rolling objects.
Coconut Cannon: 45 damage to everything in the lane and a 3x3 area around the end of the lane. However, this is for a high cost. And it used to do 90 damage, not 45. Y U NERF IT POPCAP?
Laser Bean: Jalapeno effect, but for 200 sun. 100 if you dig it up afterwards with the 50% refund, but even then the only advantage compared to Jalap (aside from being free) is recharge timer.
Citron: Highly situational. It's like a Laser Bean, but insta-killing machines or Gargs. The problem is that it will also be blocked by said zombies. For its cost, not an effective boost.
Fume-shroom: Around 75 damage, close to massive, and it pushes back everything in the row. For 125 sun. Laser Bean is useless compared to this.
Guacodile: Not even worth metioning really, as it does less damage than Fume-shroom, with no knockback, for the same cost. Useless boost.
Chomper: For 150 sun, kill three zombies and push back everything else. Not effective compared to Fume-shroom.
The best boost here is most definitely Fume-shroom, for high damage and stalling effects.
Well, I have left out a few, but I've covered most PF effects. Last thing though...
PUFF-SHROOM BOOST IS FREAKING OP. YOU CAN DEAL WITH GARG PRIMES WITHOUT SUN PRODUCERS BECAUSE IT COSTS 0 SUN!
In other words, for two PvZ Math blogs in a row, Puff-shroom is the best.
P.S. Bowling Bulb was left out because although it has a good boost, it doesn't really fall into a specific category and the effectiveness is more situational than most other boosts.