Should you deadhead the spent blooms?
Portulaca generally doesn't need deadheading as it continues to bloom as long as it's nutritional needs are being met. If you want to deadhead go ahead, but it isn't necessary. Feed with a fertilizer higher in Phosphorous and Potash than Nitrogen to encourage new blooms. When looking at the three numbers on the label of a fertilizer. The first is Nitrogen, 2nd is Phosphorous and the 3rd is Potash. Super Bloom Fertilizer works well. Generally portulaca isn't super fussy.