I am preparing for the Elite Four in my Pokémon Platinum game, and I am planting Passho, Charti, Haban, and Leppa berries for use during my Elite Four challenge. The problem is, (I am really impatient and) I want my berries to grow extremely quickly. I have tried planting my berries in Growth Mulch (available from the Berry Master's wife on Route 208, if you didn't know; which sped the growth up to 75% of normal), so the Passho, Charti, and Haban berries took 54 hours (which is almost 3 days!) to grow instead of the normal 72, and the Leppa berries took 12 hours instead of the normal 16. But, it still feels like the berries are taking forever to grow. This source recommended to keep watering the berries (I know it pertains to Emerald and not Platinum), I couldn't understand a video I tried to watch, and I have found no Action Replay codes pertaining to Berry growth (there is one for 99 of all kinds of berries, but that just wastes the others). Are there any other ways to speed up the growth of berries?
I saved and turned off my game and waited a few hours, and they are growing bigger now. I think I might find waiting to be the best option. It doesn't speed growth up, but it's helping. Still, is there any other way to speed up berry growth?