I am thinking about using my lower level wizards to grow couch potatoes to get snacks to share with my higher level wizard.
Your lower wizard will have less energy to garden with but you should enough to manage. Make sure you buy the larger spell rings as you level. They can save you energy if you have a good number of plants.
THIS PAGE has a list of how much energy you get at different levels. Yes, your energy DOES go up as you level up, and you can also get gear that gives you more energy as well. My new Ice, which is 31, is already high enough level to garden Couch Potatoes, and I just set up a 3 tier garden with all the likes. Make sure you have the large area of effect spells for Water and Music, and then the level 1 bug repellent Bug Bolt. Fortunately, gardening has become easier over the years because plants will now drop their likes during regular harvesting.