Julia Horbaschk organised the donation from the trust to replace a treasured oak lost to development at the old MGM site in Heene Road.
Trees have gone to Worthing Borough Council for Victoria Park and to Heene Cemetery, a wildlife haven.
Julia, who campaigned to save the oak tree, said: “Our story progresses into a little legacy. I have handed over 12 trees so far with one or two more to go.”
The plantings tie in with the trust’s The Big Climate Fight Back campaign and mass tree planting day on Saturday.
Julia said: “Four crab apple trees have been planted into Heene Cemetery. Designated a Site of Nature Conservation Importance, the graveyard is an oasis for wildlife in the town centre.
“Another eight were planted into Victoria Park by children from Heene Primary School and eventually four of the hazel trees will become part of an edible trail.
“One rowan will go into my neighbour’s garden, right opposite where the old oak used to be.”