He鈥檚 known for his long, shaggy haircut, but HGTV star Chip Gaines just shaved all his hair off鈥 and the reason behind the drastic change will seriously touch your heart.

The Fixer Upper star teased last week on his Instagram page that he鈥檇 be cutting his hair, leaving a pretty cryptic caption in the post. Gaines wrote, 鈥淎lright, fine. I鈥檒l cut my hair. But first鈥t鈥檚 time to put your money where your mouth is. Interested? I鈥檒l be back to tell you more tomorrow. #OperationHaircut.鈥

The next day, he revealed more about his plans, sharing another photo and letting his followers know that he and his wife Joanna were challenging fans to donate to St. Jude鈥檚 Children Hospital, which treats pediatric cancer patients, and the more money they raised, the shorter he鈥檇 go.

In his caption, he joked, 鈥淚t鈥檚 come to my attention that most of you hate my current hairstyle. But how MUCH do you hate it? Now鈥檚 the time to put your money where your mouth is.鈥

He added, 鈥淣ext week, Jo and I are visiting the beautiful kids at Target House with St. Jude Children鈥檚 Research Hospital in Memphis. No family ever pays @StJude for treatment, travel or food 鈥 so basically, we want to bring them a giant check from YOU to help cover costs 鈥 lets come together to do something big to bless these kiddos,鈥 giving his followers four days to donate to the hospital. The more money raised, the more he鈥檇 cut off, adding, 鈥淲ho knows, maybe if you really exceed my expectations鈥鈥檒l buzz it all off. #OperationHaircut.鈥

And last night, his wife shared a photo of his newly shaved head, surrounded by patients of St. Jude. In her touching caption, Joanna wrote, 鈥淲e are leaving Memphis changed. Kiddos of @stjude we go with your faces on our minds and your stories in our hearts. Thank you for letting us be a part of your home at Target House. We are cheering you on every step of the way.鈥

We applaud the couple for supporting such a worthy cause and we鈥檙e sure the patients and staff were thrilled to spend some time with the famous Texans. So sweet!

Would you ever shave your head for a good cause like Chip did? Tell us @BritandCo!

(Photo via Nathan Congleton/Getty)