Governor-General Sir Peter Cosgrove and Lady Cosgrove will host the day from 11am to 2pm.

The gardens will be looking their best after all the rain across the 54-hectare former sheep station. The grounds include 12 hectares of cultivated gardens and eight hectares of irrigated grass.

Grounds coordinator Andrew Thompson said the Manchurian pear trees and flowing bulbs were looking good at the moment.

Household operations manager Lynette Mace said it was all systems go to present the house in tip-top condition for the open day.

"There's a lot of silver polishing going on," she said, with a laugh.

The ground floor presentation rooms will be open to the public, along with the extensive gardens.

Visitors can see artworks loaned by the National Gallery of Australia and furniture loaned by the Australiana Fund.

A highlight will be the dining room complete with table set for royal or state occasion. Everything from a jewellery cabinet made from 22 different timbers by Geoffrey Hannah to a pair of Minton cockatoos to a Stuart Devlin candelabra will be on display.

Take a picnic to enjoy in the grounds. Local SES personnel will also run a sausage sizzle, cake stall, and a tea and coffee stand.

Public parking will be available along Dunrossil Drive.

And to get a taste of the open day, a virtual tour of Government House has just gone live at https://gg.gov.au/government-house/virtual-tour-government-house-canberra