I have 3 or 4 pots of soil sitting in my bedroom window. Unfortunately, my taste in plants requires more sunlight than your usual windowsill plant. Having recently failed to grow papaya and avocado, I tried my hand at passion fruit. The seed packet was a birthday present from my sister. It advised full sun and warm weather, naturally. The packet also claimed that the seeds could take up to 2 months to germinate (which is not unheard of when using oldish seeds).
Having resolved to water the pot diligently and patiently waiting, I was delighted when a couple weeks later, a little seedling popped up to say hello. I made the mistake of planting all of the seeds in the same pot, but considering the super seed beat the others by eons (going on a month or 2 now), everything seems to be OK. However, for the first week or so, I wasn’t sure if it was a papaya late bloomer, or a passion fruit, or even a weed, since many seedlings look very similar.
As it began to thrive, it was obvious that it was a passion fruit, and obvious that I needed to give more care to it that I had to the papayas that met slow painful deaths. So I wondered how I could increase the solar light incident on the plant, and reflection popped into my mind. So I took a piece of aluminum foil, cut it to the diameter of the pot, cut a pie slice out of it for the plant, and placed it under the plant. Then I fashioned a little shield that I placed vertically on the side of the pot opposite the window. Now almost every ray of light that slips by the leaves gets reflected for a second chance at feeding my photosynthesis hungry baby.
I do sometimes supplement the sun with a plant light (which I did for the papayas to no avail). And my passion baby has grown quickly into a passion toddler.
The downside of course is decreased sunlight into the room. But bedrooms are for sleeping, so this isn’t a problem.