[RooRman]

If you keep the plant outside, you will have to wait for the days to become shorter before the plant will flower naturally. A minimum of 12 hours of darkness per day is required to induce flowering in cannabis plants.

If you move the plant inside, you can induce flowering whenever you wish using a 12/12 light/dark schedule. You can use a timer on the HPS to accomplish this, but you cannot use one on the floros.

Most strains will show their sex, either male or female, within one week of the 12/12 light/dark schedule. Most strains will finish flowering at around 60 days from the start of the 12/12 schedule, but this is highly variable.

However, your plant has gotten pretty big. If you wait until the days get shorter the plant could be a monster by then and will need almost direct sunlight during daylight hours to flower to it's full potential. In addition, a 100w HPS would be quite inadequate for a plant this size. The floros. will only put additional blue light into the spectrum and will not help much during the flowering process. The red/orange spectrum of the HPS is much better suited to this task. I would suggest a 250w HPS system for a single plant this size. If this cannot be had, I would simply use the 100w HPS only and see what happens. This is after all your first grow.

In addition to lighting one should consider a flowering fertilizer. Fertilizers high in Phosphorus (second number in the N-P-K ratio) are suitible for flowering growth. These can be as specific as the popular brand Fox Farms "Big Bloom" or "Tiger Bloom", or as simple as some organic tomato fertilizer found at your local garden store.