The gardens re-open to the public on that day.
The society has chosen Darlac as its garden tools supplier. The new shop will also sell gifts, garden products and garden cosmetics.
The gardens will also continue selling roses.
Darlac managing director Peter Darban said: "We are delighted that the RNRS has chosen us as its single supplier of garden tools for the new shop at Chiswell Green in St Albans.
"Darlac is increasingly being recognised for its extensive collection of quality garden tools as the list of independent garden centres now stocking Darlac products continues to grow. In the last three years alone Darlac’s trade sales has increased dramatically and continues to grow."
Darlac has recently announced that it will be sponsoring various Royal National Rose Society Amateur Rose events to be held this season.