Different plants respond differently to stress (much like people). Many plants, like this brilliant 'Santa Barbara' bougainvillea, think it's best to send out as many flowers as possible to help spread seeds before it may expire. Although it is considered a tropical plant, and I think of tropical plants as ones coming from lush, rain forest-y places, many are extremely drought tolerant. This is probably why the most beautiful and prolific bougainvilleas are usually found in the most desolate places like abandoned buildings or deserted parking lots and yet we can't get them to bloom in our own backyards.
Every year I have the queen palm trees at our SJC home trimmed in the fall when they put out their flowers and annoying seeds. They cover the ground with scrappy little flower petals then cherry-sized seeds that make a big mess when you have 100 of them. This year I have already had to bring my tree trimmers out once in the summer because they were uncharacteristically blooming and seeding all over the place in July, I'm assuming due to the lack of water. We removed the seed pods, flowers and any dying branches. As you can see here it is almost time to do it again.
Although it is impossible to remove established acanthus, they do not like the drought at all. I have lost a whole bed of them in Laguna and the ones I have placed here and there in the shade in SJC are not fairing well. As you can see, this one has lost all it's leaves but is desperately trying to establish its legacy by expending every last bit of energy in putting out this lone flower stalk. I'm sure it will survive and I hate to say it, but I have never seen them sprout from seed in my gardens yet.
The good news is that a bit of stress can force a stubborn non-bloomer to finally bloom like this little banana tree! I have grown bananas in Laguna for many years and planted a couple trees as soon as we moved into SJC, but they never bloomed. This week I was delighted to see the first flower on my little 'Ice Cream' plant. Hopefully by the time the holidays come I can show the grandkids how bananas grow.
Not all plants respond to stress with prolific blooms. My roses have been almost non-existent this year. They seem to pull in and reserve all their strength to withstand the cut back in water and when they do bloom they are small, sad flowers. I have fertilized same as usual, but they prefer to wait it out until more water is available. I have noticed that the vacant lot down the street where a gentleman grows dozens and dozens of rose bushes for his hobby of showing roses in contests is as prolific as usual. He does use synthetic fertilizers which stimulate the blooms no matter what is going on with Mother Nature. Of course along with that he has to use lots of sprays and lots of water, but he does have glorious flowers!