"I’ve spent the last five years cultivating luminous pumpkins,, flying pumpkins, singing pumpkins, and exploding pumpkins...."
-- Dagbert Pips (DP4)
Pumpkins R Us is a specialty pumpkin-growing business, run by Dagbert Pips (DP4)
Dagbert Pips, the proprietor of Pumpkins R Us, was interviewed in a Daily Prophet article on the new Ministry law cracking down on Hallowe'en celebrations. Following years of cross-breeding and cultivation, they stock many different types of magical pumpkins. Mr Pips and his store are almost certainly in located in Britain and likely to be in Diagon Alley, although we have no way of knowing this for sure (DP4)
This company's name references a particular type of store name, usually aimed at parents with children, that replaces the word "are" with the letter "R", such as the US conglomerate retailer Toys R Us. The single "R" is usually printed backwards, to lead the observer to associate it with a child who is just learning to write.
While the date printed on DP4 is 1 October 1999, the timeframe for these events is 1992-1993.