We had a great surprise in one of our planter beds recently, and I thought you might find it interesting.
About 10 years ago while out shopping with the kids—they were about 5 years old—we came across a display of those little colorful grafted ornamental cactus plants. The kids had to have one, so we let them each pick one. Each of these was a small cactus "trunk" with a brightly colored round cactus grafted on top. Within a few weeks the colorful balls fell off. Instead of just throwing what was left away, (the trunk part) we just set them in the back of one of our planter beds in the front yard under a robellini palm (Phoenix roebelenii). They were no more than about 3" or 4" tall (7.6 cm to 10.1 cm).
Fast forward 10 years and one of these cactus remnants has grown up one of the trunks of the palm tree with parts hanging nearly all the way back down to the ground. In all that time it was a plain, simple cactus. Then one morning I walked out the front door on my way to work and was stopped in my tracks by a large white bloom. I had never noticed the bulb forming and this was a complete surprise. I took pictures but unfortunately the bloom was already deteriorating and mostly closed. Within a couple of days it fell off.
I then started to check the cactus regularly for any signs of another bud, and a couple weeks later I found another starting to grow. I watched it daily waiting for it to bloom so I could get some good pictures. One morning it had bloomed! Unfortunately, like the first one it was already pretty sad looking and closed up.
A couple of weeks later there was another bud forming. Again, I was determined to get some good pics as soon as it bloomed. Now, I know that you have probably already twigged to the obvious, and I should have as well, but for some reason the obvious answer never occurred to me. Until just the other night. That night for some reason, probably because she knew, my daughter went out the front door at about 11 PM to take a look at the flower bud that I was sure would bloom the next day. And then came right back in and ran around trying to find her camera. "The flower bloomed!" Of course. It's a night blooming cactus, as so many cactus are