No, it is impossible for it to learn all 3.
It can get:
Leech Seed+Stealth Rock: Torterra
Spikes+Leech Seed: Roserade, Cacnea, Cacturne, Roselia
Stealth Rock+Spikes: Dwebble, Crustle
Now, all three moves are legal. Use the "Spikes and Leech Seed" combo, and then teach it via Move Tutor in B2/W2.