By the grace of Regenerator, Tangrowth has become one of the most resilient physical walls in the game, second only to Protect Gliscor after its Toxic Orb has activated. Tangrowth's home is generally on defensive teams, where it can be used to scout Choice Band attackers by taking the blow and regenerating out to a resist, or wearing down the other team massively with it's support movepool featuring Sleep Powder, Leech Seed, and Knock Off. It can also be used effectively on balanced teams for the same purpose and to counter top physical threats, being hard for even Breloom to toss aside when asleep. A small special defense investment will allow it to take a Hydro Pump or two as well. It's not going to be fighting for top 5 usage any time soon but it can still be an effective fit in numerous teams.
This set takes all of Tangrowth's greatest strengths and rolls them into one set. With maximum defensive investment, Tangrowth has enough physical bulk to rival old standbys such as Skarmory and Hippowdon, while still maintaining the ability to hit back thanks to its naturally high offenses. Combined with Regenerator, this makes Tangrowth a tremendously effective defensive pivot in the current OU metagame, able to switch in and threaten top threats such as Haxorus, Dragonite, Scizor, Rotom-W, Terrakion, and more; it can then switch out afterwards none the worse for the wear thanks to Regenerator. This set can also potentially break VoltTurn chains, as Tangrowth's massive physical bulk and resistance to Rotom-W's STABs allow it to sponge U-turns and Volt-Switches before hitting the switch-in with Sleep Powder or a super effective move. Regenerator also makes it very hard for VoltTurn teams (or any team for that matter) to wear it down over time, meaning Tangrowth will frequently survive for the entire match if played carefully
The choice between Power Whip and Giga Drain is somewhat of a tossup, as, while Power Whip hits most targets harder, Giga Drain recovers health and isn't affected by Burn. Giga Drain also hits some specific targets harder than Power Whip, such as Slowbro. What Hidden Power Tangrowth uses determines what it can check and what it can't, so it is vital to pick the appropriate one for your team. If Dragon-types and Gliscor are a bigger threat to the team, then Hidden Power Ice is generally the move of choice. If Scizor is a bigger concern, or the team can't afford to be set up on by Ferrothorn or Forretress, then Hidden Power Fire is a solid option. Both can be used on frailer Grass-types that resist Tangrowth's other attacks, though bulky ones such as Virizon and Celebi will probably shrug off the hit. Sleep Powder is a given on almost any set, as it allows you to instantly eliminate one of Tangrowth's counters. The choice of utility move in the last slot depends on what the team needs most. While Leech Seed is very useful for discouraging opponents from setting up on Tangrowth and increasing Tangrowth's longevity, Knock Off is an interesting option that can cripple almost any Pokemon permanently. Knock Off also reveals the opponent's item, which can be crucial to know with some Pokemon such as Salamence and Haxorus.Team Options & Additional Comments >>>
Although not the fastest Chlorophyll sweeper, Tangrowth holds the second highest combined attacking stats of any with this ability, as well as significant bulk even without any investment. Power Whip is present as obligatory STAB, being the prime choice here due to its power, and due to the hard hit on Tyranitar, who always gives sun teams issues. Hidden Power Fire is a great choice in sun, netting you OHKOs on most Grass-types even without a Growth. Earthquake gives powerful coverage on most Fire-types, but Rock Slide can be used instead, still hitting Fire-types hard and Heatran neutrally, but allowing for a super effective hit on the Dragon / Flying types, all of whom would wall this set otherwise. Growth is preferred on a sun sweeper set, as it boosts both attacking stats two stages when used in sunlight, though Sleep Powder is still viable.Team Options & Additional Comments >>>
Stun Spore and Knock Off are viable on any defensive set, crippling faster switch-ins or threats and removing Leftovers recovery, respectively. Toxic is less desirable due to Tangrowth's other moves being of rarer distribution and thus more useful to most teams, but is still usable. Sleep Powder is the main reason for these moves being less viable, as its ability to remove one Pokemon from the match almost entirely is often more useful. Amnesia is the final support option that can be utilized, boosting Tangrowth's Special Defense from awful to acceptable levels. However, on a defensive set where it is of use, moveslots are sparse and other coverage or status moves will often prove far more valuable than the extra special bulk would. Synthesis looks useful on defensive Tangrowth for added recovery, but is illegal with Regenerator. Using it with a sun-related ability is the only possible option, where it is quite viable due to the immense recovery it offers. Rest and Sleep Talk allows Tangrowth to function as a status absorber, but the lack of two moveslots and inability to control Sleep Powder's use is a huge downfall.
Most viable attacking moves have been mentioned, aside from Nature Power (mimicking Earthquake in Wi-Fi battles) to replace Earthquake wherever it is used, as it has much greater PP. Unfortunately, it is technically a status move and as such can be prevented with Taunt, making Earthquake the superior choice unless you desperately need the extra PP. Tangrowth having access to such a huge array of coverage moves makes a Choice Band set seem attractive, but his appallingly low Speed means his switch-in options are extremely limited and he can be revenge killed very easily. Similarly, a Swords Dance set is possible, but his Speed stops any use for this besides some wallbreaking, where he is outclassed.
SubSeeding is a possible direction to take Tangrowth in, as with practically every other Grass-type, and given his ability to regenerate health for another Substitute upon switching out, he initially seems a prime candidate. However, his awful Speed and Special Defense let him down despite his physical bulk and 101 HP Substitutes, meaning Shaymin, for example, often does the job better. In general, Tangrowth sees better use as a defensive pivot, able to repeatedly and easily switch in thanks to his Regenerator ability. If you do choose to run a SubSeed set, Giga Drain is the attack of choice for added healing while Hidden Power Fire lets him deal with Ferrothorn. As per the other sets, Sleep Powder can deal with a single other counter, or another support option could be used.
When using Chlorophyll in the sun, Wide Lens can be utilized if you are using several inaccurate moves, but the power drop is significant unless running Growth to make up for it. SolarBeam is also viable on sun sets due to its sheer power, but it can be turned against Tangrowth, as a Tyranitar or Politoed switch-in will lock it into a charge-up turn. SolarBeam also restricts Tangrowth severely in the role of countering Tyranitar and Politoed, which is a crucial role he can otherwise perform quite nicely.
Checks and Counters
Tangrowth, while incredibly bulky on the physical side, can be dealt a lot of damage by even strong neutral attacks to his weak special side. Anything specially powerful that outspeeds and sponges most of his attacks can comfortably switch in and threaten to KO him. However, due to Regenerator, Tangrowth can easily switch out when a counter comes in, wearing them down with entry hazards and other damage, while remaining at good health himself, which often means tricky prediction is required to deal with him effectively.
Fellow Grass-types counter Tangrowth relatively well—Virizion earns a special mention for its resistance to Tangrowth's STAB, immunity to Leech Seed and good Special Defense to sponge super effective Hidden Powers while setting up Calm Minds. To a lesser extent, Celebi and Breloom can set up on Tangrowth too, and are able to shrug off or avoid any status Tangrowth might throw their way too with Natural Cure and Toxic Orb, respectively. Ferrothorn poses severe problems unless Hidden Power Fire is used, as it is immune to almost all the residual damage Tangrowth likes to exploit, and is able to set up entry hazards against Tangrowth.
Any special Fire-type can very easily eliminate Tangrowth, especially if they run Air Balloon to avoid Earthquake. Heatran in particular is a potent threat due to its ability to easily survive unboosted Focus Blasts, as is Chandelure for being immune to them; both also resist Grass and are immune to Fire. Worse still, however, is Volcarona, who resists Grass, Ice, and Fighting, and is neutral to Hidden Power Fire and Earthquake. It also packs two STABs which can OHKO Tangrowth, as well as Quiver Dance to threaten the rest of your team.
Counters for the Chlorophyll set in the sun include any positive-natured Choice Scarf user with a base Speed of 85 or higher and a super effective move. Notably, Choice Scarf Latios and Latias with Hidden Power Fire or Ice are great counters. Faster Chlorophyll users with Hidden Power Fire or Ice serve excellently as well as long as they can get in safely. Politoed and Tyranitar often carry Ice Beam or Flamethrower, respectively, and if they switch in safely, they will take away Tangrowth's Speed boost. Both have higher base Speed than Tangrowth, and can safely OHKO if they manage to switch in, but only if they run enough Speed EVs to avoid being OHKOed by Naive Tangrowth first.