Nintendo 3DS. The first Bokujou Monogatari game localized by XSeed Games. [ Game Guide ] JP release = Feb 2014. NA release = Mar 2015. EU release = Dec 2015.
Just keep using fertilizer on one or two (depending on how much of each you want), then when they're fully ranked, chop them down, make seedlings, and replant them. Alternatively, you can also use fertilizer on all of your trees, if you don't want to wait for them to become fully grown again.