WOW Power Leveling: You have to wait for that full moon or elemental day in the game
Feeding Times - You should always feed on the day of the elemental ore you are trying to get WOW Power Leveling. Plain and simple, this will add elemental strength to the plant so you next checks may need adjusting. Do not check your plants after feeding. I find this lessens the chance of getting ores.
Harvest time: Anxious as you may be wait for the right time!!!
Harvesting: This is the most exciting time for a Gardener. Also the time when most fail. You have to wait for that full moon or elemental day. If by chance you did not get a full moon timed properly, do not despair. You know they are ready to harvest when your plants start to glow.
I find that there are different glowrates as well as do several other people. The one I find to be the best is when the plant is pulsing with light and several sprinkles are falling from the bud. This to me is the best time for a harvest. It may be hard to determine what it looks like but with time you will get the hang of it.
I also find that if there was a weak plant (Low elemental strength per you log) to examine one More elemental day harvest in 1 game week, even if it means missing a full moon. An anxious gardener is a broke gardener.