Speaking of Mario Komsta (previous post), this instructive and somewhat self explanatory photo about a lesser known benefit of fertilizing, is something he cooked up. I don’t remember where I found it (facebook?), but I do know where you can find Mario.
Fertilize! Skip ahead to the fourth point unless you are a beginner (or, either ignorant or lazy – or both)*
Many, if not most people under fertilize their bonsai. I imagine it’s laziness on some people’s part and ignorance on others (they’re related). There’s nothing we can do about the laziness part, but, maybe we can help with the ignorance.
First, we’ll state the obvious: fertilizing helps keep your bonsai healthy. Plants need a range of nutrients to sustain themselves, stay beautiful, help resist pests and disease and so forth.
Second (something that should be obvious but isn’t to everyone): you don’t starve bonsai to keep them small. Bonsai are kept small by pruning (top and roots) and by growing them in small containers.
Third (you’d be surprised how many people don’t quite get this): fertilizing encourages growth and growth is critical in developing quality bonsai. You want trunks to thicken, branches to develop, nebari to develop, and so forth. Unhealthy plants don’t grow much, or worse, their growth is leggy and weak.
Fourth (the purpose of the photo above): ample, (even intensive) fertilizing can encourage back budding (budding on old wood). Some trees don’t back bud easily (pines for example) so they need some encouragement. In the photo above, Mario points out a bud that popped up on eleven-year-old wood (on a pine no less!). He attributes this not very common occurrence to fertilizing.
*Takes one to know one
Disclaimer: I actively indulge in both ignorance and laziness with alarming regularity. No high ground around here.