The paper merchant held the latest of its tree planting action days in March in an initiative with conservation charity the Woodland Trust.
Customers and staff dug the saplings into ground at Pullabrook Wood in the Bovey Valley National Nature Reserve in the south-east corner of Dartmoor.
Marketing executive Brad Goldsmith said: “We've run lots of customer events such as driving and sailing days and football at Wembley stadium, but there's something special about the tree planting.
“I think it's because people connect in a very special way to nature and the environment. In the last couple of years we've noticed even more how much people get from these days.
“They are a great example of how customers make a real difference in creating habitats that are vital to both wildlife and people.”
Staff and 20 customers braved torrential rain and wintery conditions to help replant a forest area that had suffered an outbreak of a tree disease spread by Japanese Larch.
The non-native tree species was introduced to the woodland shortly after the Second World War and the fungus-like disease, Phytophthora ramorum, has spread across south-west England.
To limit chances of continuing infection, larches were felled at the site, which was prepared for tree planting last November.
The 1,000 new saplings planted comprised of a variety of native woodland species including oak, birch, blackthorn, and wild cherry.
During the past year more than 65,000 trees have been planted as part of Premier’s Carbon Capture scheme, which has helped capture 11,000 tonnes of carbon dioxide (CO2) emissions.
Carbon capture is the process of capturing waste CO2 in the atmosphere. Trees absorb CO2 and carbon capture is one way of soaking up some of the CO2.
Last October Premier Paper Group hosted its third annual tree-planting action day at Heartwood Forest, Hertfordshire. Premier started carbon capturing by planting in 2011.