Err, first I have installed the drip line, then I did the actual search on the web for watering needs of these plants :)

Turned out lilacs and roses need deep watering at 3-4 days whereas petunias and other seasonal flowers need shallow watering, perhaps even daily.

Could I activate that zone every 2-3 days having 0.5 GPH emitters for summer flowers and 1 GPH emitters for the lilacs and roses and leave it run for, say, 2 hours ?

Or should I better install a stopcock on the drip line and thus water the two kind of plants separately (still on same zone, but I am able to divide them with a cock). Or something else ?

Thank you!