FX announced renewals for the two freshman series last week, both of which will present their sophomore seasons sometime in 2008.
Elsewhere, ABC Family has extended the sophomore season of Kyle XY, while Lifetime Television has renewed its vampire series Blood Ties for a second campaign.
For its part, FX also announced that the 13-episode fourth season of Denis Leary's fireman saga, Rescue Me, will bow June 12 at 10 p.m., returning to its original Wednesday-night roost.
Legal drama Damages, starring Glenn Close, will bow in the Tuesday 10 p.m. slot starting July 24.
“We're very proud to have managed, in the toughest possible competitive environment, to launch Dirt and The Riches — two highly original series that have resonated with our audience as strongly as The Shield and Rescue Me,” said FX Networks president and general manager John Landgraf in a statement.
“FX now has six original dramas, more than any network in the history of cable television, cementing the network's status as a leader in quality original series,” he added. “We congratulate all of the wonderfully talented actors, writers, directors and producers who worked so hard on these shows.”
FX officials indicate that The Riches and Dirt have produced solid numbers among the network's target demo of adults 18-49. Dirt's cumulative delivery for its rookie season was 3.66 million adults 18 to 49 and 5.2 million total viewers, while over the first seven episodes of The Riches, the series delivered 3.9 million in the demo and 5.9 million watchers when gauged on a cume basis.
By way of comparison, the third season of Rescue Me posted a weekly cume audience of 3.64 million among adults 18 to 49 and 5.66 million total viewers; The Shield's fifth season grabbed 3.65 million adults 18 to 49 and 5.65 million total viewers; and plastic-surgeon skein Nip/Tuck cut its way onto the screens of 5.1 million people in the demo and 7.2 million overall. The latter is basic cable's top performer among Madison Avenue's most-targeted demo, according to FX officials.
ABC Family has picked up 10 more one-hour episodes of its highest-rated original series, Kyle XY, boosting the second-season total to 23.
Meanwhile, Lifetime has given the green light to 10 more hours of vampire show Blood Ties, the first of which will come out of the box this fall.