The symbol group will launch an environmental campaign this month by teaming up with the Woodland Trust. As part of the Rooted in the Community scheme, Spar will plant 2,700 trees - one for every Spar store in the UK.
Retailers will be able to participate by offering local schools the chance to win one of 600 hedge and copse tree planting packs through an in-store leaflet competition.
The party atmosphere got off to a flying start at the Spar-sponsored European Athletics Indoor Championships in Birmingham. The symbol group benefited from weekend-long coverage of the championships and the SPARk arena in the city centre - an interactive sports park visited by hundreds of school children.
Further activity includes the chance for retailers to boost sales with the group's biggest ever promotional activity, Golden Deals, in June.
Retailers will also receive birthday party packs to enable them to host a party with staff and customers while raising money for the NSPCC and Children 1st.
Celebrations will culminate with the group's Birthday Bonanza event on September 22.
Spar group marketing director Susan Darbyshire said: "We've got exciting plans and need retailers to make a big noise. Our Golden Deals promotion starts on June 7 and will be supported by a heavyweight media campaign. Our big party in September will be a night to remember and a chance to celebrate the past but also look forward to the next 50 years."