Enter Purslane. It's a close relation to Portulaca, commonly called Moss Rose. But Purslane has a lower growing, more trailing habit than common Portulaca. Plus it can take the heat like a desert trooper. Purslane comes in Red, Yellow, Pink, single bloom (This is the Rio series) and also a double yellow and red flowering form (This is the Fairy Tales series).
Purslane is easy to grow and doesn't require you to station yourself next to the basket or the pot with a hose or a watering can. Once-a-day watering is all it needs, even in the hottest weather. Sometimes every other day!
It's not necessary (and it's probably counter-productive) to fertilize Purslane every time you water it. Just give it enough fertilizer to grow well - once a week with a good 20-10-20 soluable liquid or Miracle Gro will do - and it will reward you with tons of blooms all summer long. The blooms do tend to close at night so this is not a good one for viewing at night. But you will have plenty of open flowers the next morning.
If your Purslane is growing in a peat based soil mix allow the soil to become somewhat dry then water well until the water comes out of the bottom of the basket. In other words; soak it well. This should hold the plant until the following day, no matter how hot it gets or how big the plant gets.
Most purslane is not available from seed and must be grown from cuttings so that all of the clones will exhibit the same characteristics of heat tolerance and vigor and especially flower size. These plants will set seed and the seeds will sprout but very few grow true to form of the original plants.
So if you want the true original varieties you will need to keep your plant from freezing in the winter or else purchase new ones each spring.