"It has just snowballed," Reed said.
"Our next step is performing. We've already had a few offers to play, but we want to lift their confidence so they can try all the clever stuff before we go live.
"But so far, we've been creating wonderful musical memories, and it's going from strength to strength."
Reed has been performing for the past 20 years, currently playing in Celtic rock band Shenanigans.
Five years ago, he began holding ukulele practice sessions at The Chill restaurant in Lower Hutt and the Petone Workingmen's Club, with the two groups eventually forming the Hutt Valley Ukulele Orchestra.
Relocating to Kahutara last year, Reed decided "Wairarapa could do with [his] services" and pitched the idea for a jam night to Top Pub owner Ursula Murphy.
He said the first session in Greytown defied his expectations.
"There were at least 150 people there with their ukuleles -- I could barely get through to the bar.
"It was standing room only".
Reed said his 75 regulars are a joy to work with, and he is undaunted by teaching such a large number.
"It's easy because they're so receptive. Everyone who comes wants to learn and wants to get better. We try and make it a non-threatening, supportive environment to practice in. The ukulele is much easier than other instruments. It brings instant satisfaction."
Members are currently working through a range of repertoire taken from Reed's collection of ukulele songbooks, including Irish folk songs, show tunes, Americana and contemporary tunes.
"It's an electric atmosphere at jam nights -- everyone leaves with a smile. The next plan is to bring them from remembering where to put their hands for chords to really performing the songs."
Reed said he enjoys the social aspect of the group.
"We've got a lady who says the group is the only time she gets to see other people in the week. We even had an engagement. The couple met when they started coming to jam nights, which is wonderful."
For more information on the Wairarapa Ukulele Orchestra, contact Justin Reed on 027 495 8462.