Oh, and now that you have the mela rare oak, you may want to play around with pricing. I have been taking every plant in the game and testing what is the highest possible price you can get. I play the game at average (options) difficulty and I always use 3 fertilizer bombs. I have all of the ornaments in the nursery although I think those only bring more visitors to the nursery and don't impact the price. The mela rare oak is at 301 right now. I will try to sell it for the next level up. I am not currently at the top for everything.
Mela Rare Oak 301
Fabled Lemonbush 1011 (tops out here)
Four Petal Maple 122
Aureus Scandens 306
Nox Orchid 229
Rosaceae Fern 149
Today I will test how much higher I can go on all but the Fabled Lemonbush which I have already tested several times. My niece has had problems getting that much for the Lemonbush but she doesn't have all the ornaments which makes me think it might be a factor. But I have found that plants sell for way more than the Nox Orchid's suggested retail price. For example, The Venus Ridgeball nox says 226. I sell it for 476 and that is the top price. The next step up and none sell. I generally plant 15 of each thing to see if anything will sell.
A great site to go to help you is last day of work and find the strategy guide section for plant tycoon. Borg has created a virtual seed tray which stores all your seeds (not the limited number allowed in the game). So I never sell seeds. I save them all. His program which also show you which plants you have breed, which seeds you currently have, which ones you used to have but got rid of and what you have to cross pollinate to get any particular plant and what things you need mutate to get some of the tier four plants/foliage. You just click on Spotted Bamboo for example. And the program will look into your seed tray and tell you what combination you need to cross pollinate to get the spotted bamboo. Everyone will have different seeds so the program looks at all possible combinations and tells you the best one for you. Some plants will be complicated -- many steps and some are just two plants.
But I like that I can see what I own. What I have already acquired. What I haven't ever gotten. Makes your progress more clear.
Hope that helps.