He doesn't learn by level. First, go underground (anywhere) and find a Heart Scale. Now go to Pastoria City and by the city map sign, go down 7 paces, and then by the house on the left, go to the right house (8 steps) and talk to the guy there. (He will be saying 'Here where I am standing, I'm smack-dab in the middle of town.'). go in. Talk to the other guy and give him your Heart Scale. He'll ask you what Pokemon should learn what move and your wanted move will be there but you have to have an empty space for it and if you don't have an empty spot for it then he'll ask you to delete 1 of your moves however he can't delete HM moves. Also if you're replacing for a HM, go to Canalave City and the house below the PokéMart and talk to the guy in the house and tell him to forget the HM you want gone then you can return to Pastoria.
On a normal level-up scale, Torterra learns Wood hammer at lvl 1 (!) so therefore you need to bring it to a move tutor with a Heat Scale to relearn the move.
at lv one . check marriland and serebii or bulbapedia
After torterra is able to learn it, if you select no then you can use a heart scale and then teach it the move using the heart scale tutor
You have to upgrade your torterra to level 39 before it can learn synthesis.
Torterra can learn Leaf Storm at level 57.
On a normal level-up scale, Torterra learns Wood hammer at lvl 1 (!) so therefore you need to bring it to a move tutor with a Heat Scale to relearn the move.
at lv one . check marriland and serebii or bulbapedia
After torterra is able to learn it, if you select no then you can use a heart scale and then teach it the move using the heart scale tutor
you have to catch abomasnow or torterra. It isn't a TM
blazeken flare blitz tor torttera wood hammer
Nature shouldn't matter. Frenzy Plant, Leaf Storm, Wood Hammer, Earthquake.
You have to upgrade your torterra to level 39 before it can learn synthesis.
Torterra learns Wood Hammer,but you'd need to go to the guy who makes your Pokemon remember its moves with a Heart Scale.
The Torterra moves are: tackle, withdraw, absorb, razor leaf, wood hammer, curse, bite, mega drain, earthquake, leech seed, synthesis, crunch, giga drain, leaf storm, and frenzy plant. Torterra learns all these moves by level 80. (frenzy plant is learned from some guy in a house near the resort area, and the fight area).
Torterra can learn Leaf Storm at level 57.
Torterra can be taught Solar Beam with TM22
In Pokémon Diamond, Torterra is capable of learning Tackle, Withdraw, Absorb, Razor Leaf, Wood Hammer, Bite, Razor Leaf, Curse and Mega Drain otherwise those moves require the use of Heart Scales for Torterra to know them. Torterra learns Earthquake at Level 32, Leech Seed at Level 33, Synthesis at Level 39, Crunch at Level 45, Giga Drain at Level 51 and Leaf Storm at Level 57.