I spotted a nice group of coleus at a local park last October, including a couple unusual varieties which are not found in your typical cheap "rainbow" seed mix. Knowing how easy it is to reproduce coleus by cutting, I decided to take home a small stem of those, to grow them as houseplants. They are grown outside as annuals in my zone and they usually don't even make it to the winter.
Fast forward to May. Long story short, I managed to root them in water, pot them and see new growth. Problem is, at the time I cut them, they were already wilting and flower-ridden. The cuttings have somehow "inherited" that trait and they produce too many flowers and too little growth.
One of them has grown less than a dozen leaves and at least the same amount of floral stems. I've tried both pruning the floral stems and leaving them be, to no effect. In fact I've already managed to germinate seeds from that one. The other one collapsed from stem rot, but I cut the tip and rooted it again, and now I have a one-inch-high coleus... which is already starting to produce a flower stem!
I've grown coleus before, both from seed and cutting, and I've never seen any of them to be so eager to flower before. I've always found that the opposite was true, they tend not to flower at all unless they are outside, or getting a lot of light inside (which my place doesn't have). I don't know the reason. Internet suggests it might be the fertilizer, but I don't think so, because I use a generic "green leaf" one with at least double N than P and K.
Question is, how can I coerce my coleus into NOT flowering and growing more leaves instead?
PS: Many people say that coleus weaken/die after flowering and you should cut the flower stems ASAP. That's, at best, not necessarily true. My inlaws have a large coleus which they basically don't care about (other than watering it every other week), it's leggy and ugly as hell but otherwise healthy, and it has been growing and flowering for at least five years with flower stems as long as a handspan.
