On 14 October 2015, Garrard was appointed as the manager of Boreham Wood, following the resignation of
Ian Allinson, making him the youngest manager in England's top five divisions. In Garrard's
third season in charge, he led Boreham Wood to the National League play-offs for the first time. His side defeated
AFC Fylde and
Sutton United to set up a play-off final with
Tranmere Rovers at
Wembley Stadium in which Garrard's side were defeated 2–1. Also in this season, Boreham Wood defeated Football League opposition for the first time in their history when they defeated
League One side
Blackpool in the
FA Cup first round. In the
2021–22 season, Boreham Wood reached the fifth round of the FA Cup for the first time in their history. Having reached the third round, his side defeated League One side
AFC Wimbledon 2–0 before winning away at
Championship promotion chasers
AFC Bournemouth 1–0. His side were eventually defeated 2–0 at
Premier League club
Everton. In the
2022–23 season, Boreham Wood reached the play-offs again but lost in the semi-finals to
Notts County after a late goal in extra time. On 2 April 2024, following a defeat to
Southend United that left relegation-threatened Boreham Wood three points from safety with just four matches remaining, the club announced that they would part company with Garrard following the final match of the season. Following a 0–0 draw with
Ebbsfleet United on the final day of the season, Wood's relegation was confirmed. On 13 September 2024, Garrard returned to Boreham Wood as manager following the sacking of
Ross Jenkins. == Managerial Statistics ==