Level 53.
Venusaur learns solar beam at level 65 in Red, Green, Blue, Yellow, Gold, Silver, Crystal, Ruby, Sapphire, FireRed, LeafGreen, and Emerald. But Venusaur learns solar beam at level 53 in Diamond, Pearl, and Platinum.
no it can not learn it but you can get ice beam as a TM is number 13
Venusaur Learns:- Growth Lv.43 Sleep Powder Lv.55 Solar Beam Lv.65
Venusaur: Sunny day, Solar beam, Synthesis, Sludge bomb Charizard: Fly, Flamethrower, Sunny day, Solar beam Blastoise: Earthquake, Surf, Skull bash, Dig
(it is tough to say but a torterra with earthquake would win but if it doesnt know it venasaur would win do to resistances) what the no way thisis what will happenn torterra will use solar beam venusaur will do the same torterras one is stronger torterra uses harden venusaur uses takkle there both defeted
Venusaur learns Solarbeam at level 65 in the three first Generations, but learns it at level 53 in Gen 4 and 5.
Solar Beam does 120 damage and has 100 accuracy
Hyper Beam.
Simi Toxic Solar Strike , Solar beam
Groudon can learn Solar Beam at level 50.
I will give you a lvl 90 blastoise moves hydro pump, surf, ice beam, blizzard or a venusaur lvl 88 moves frenzy plant, razor leaf, solar beam, earthquake... i prefer a legendary but an eeveelution of any sort would also work.