Question
QUESTION: I have 2 orchids, both Phalaenopsis. One hasn't flowered in 4 years although it's leaves are green. I give it orchid plant food every 6 weeks and it sits on kitchen window sil facing north. The other one I was given 2 years ago and has flowered only once. I have reported the one from 4 years ago 3 times. The roots were dead (brown) but something must be feeding the leaves. Thanks

ANSWER: Gil, the usual reason for reluctance to flower is insufficient light. If the leaves are dark green, the light may be fine for growing but not for blooming. Leaves should be a light green to reflect adequate light for blooming.

I note that some novice growers consider dark roots to be dead. Any root that is firm is very much alive.  Dead roots are mushy and may have lost part or all of their outer covering (called velamin). It sounds like the roots are fine and thus are feeding the plant. No more repotting. You need to give the roots time to establish themselves.

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QUESTION: Ok I must assume its not getting light as there is a canopy on the outside of the kitchen blocking light entering. I don't recall the roots being mushy. It did grow new silver roots that shoot upwards outside of the pot but there's hardly any roots in the soil itself. Yes the leaves are very dark green in both plants although in both, leaves have does in past year turning yellow.

Hopefully it will bloom soon.

Answer
Yes, I would assume that. Once you achieve sufficient light levels, it will still take the plant at least a month or two to produce the necessary hormones and pigments essential for flowering, so don't expect immediate changes.  Many authors recommend east windows for growing phalaenopsis.  Unfortunately, not everyone has an east window for growing. While north windows may be okay in the winter as the daylight is more pronounced then, the rest of the year the light levels are likely to be lower so you'll need to take that into account.  Also, monitor the temperature in the vicinity of the plants as they can become quite cool on a windowsill in the winter.