What it does
Leech Seed plants a seed on the target. At the end of each turn, the target loses 1/8 of its maximum HP, and the user (or a designated ally in doubles) recovers that amount. The effect persists until the target switches out.
Grass-type targets are completely immune. Rapid Spin removes the effect from the seeded Pokémon. If the target has Liquid Ooze, the effect reverses — instead of healing the user, the drain damages the user instead.
1/8 per turn is modest on its own, but it compounds: two turns is 1/4, four turns is 1/2. Combined with the user's own recovery (held items, passive abilities), the seed creates a double pressure — the target erodes while your side heals. Each turn the target stays in, the gap widens.
This is not a direct damage move. The turn you use it, you deal zero damage. Its value is purely temporal — the seed only matters if the target stays on the field.
Who runs it
Appletun (45%) is the most common carrier. Grass/Dragon with high HP and recovery options — Leech Seed into a sturdy defensive profile keeps it on the field and keeps it healthy. Opponents have to actively deal with it or keep bleeding every turn.
Chesnaught (37%) is Grass/Fighting with high physical Defense. Leech Seed combined with its bulk creates a passive attrition profile — it sits on the field, absorbs hits, and drains back.
Trevenant (34%) is Grass/Ghost and uses Leech Seed as a sustained pressure tool alongside its other disruption options.
Torterra (26%) is Grass/Ground with a defensive bent, using the seed as support alongside its physical offense.
Serperior (15%) primarily runs special offense but carries Leech Seed as a utility option for certain matchups.
Roserade (12%) and Abomasnow (10%) round out the list at lower usage rates.
How to use it
In doubles, the key is targeting the Pokémon that will stay on the field longest. Seeding a target that immediately switches out wastes the turn — the seed clears on exit. The highest-value Leech Seed turns are when you plant it on the opponent's core attacker or support that can't afford to leave.
Pairing with passive recovery items works well. Leftovers on the seed user means each turn it stays healthy via two passive sources — the seed's recovery plus the item. For bulky Grass-types, this combination extends time on the field substantially.
Grass types are the hard counter — Leech Seed simply fails against them. You need an alternate plan for Grass-type threats.
Tips & strategy
Leech Seed paired with Protect is a clean pattern in doubles. On a turn your Pokémon uses Protect, the seed's end-of-turn effect still triggers. Your Pokémon takes no damage, your opponent gets nothing, and the seed quietly ticks down. Over two or three turns of this, the HP gap can become decisive.
Trick Room teams sometimes benefit from Leech Seed as a side tool — Trick Room lasts four turns, which is four drain ticks if the seed is already planted.
Watch for Liquid Ooze. If the target has it and your Appletun or Chesnaught uses Leech Seed, the recovery becomes damage to your own Pokémon. Know which opponents carry it and skip the move against them entirely.