Bulb. Melanies Starr- blooming troubles

[DeAnne]

I have a specimen size Bulb.Melanies Starr. This is a cross between Baileyi and Lobbii. It has grown from a medium basket size plant to a huge mature plant I have had now for 5 years.It has never bloomed. It is in a greenhouse with my cats which all bloom well. I have tried more light,given it the warmest spot,fed ,kept moist ,patted and burped it until I have run out of ideas. The bulbs are plump,leaf color medium green. It has no leaf spotting or yellowing dropping leaves or pests. It has so many new growths I can no longer count them. If only it would bloom it would be a wonder! All my other Bulbs flower regularly.

I live in Seattle,and must use HPS light in winter .The plant gets around 1500 to 2000 fc in summer and a bit less in winter. Help

DeAnne