Oooh, a mini rose for $0.99? *jealous!!* I can't find them for less than $5 here! Lucky...
Ugh, the bodybag roses. Oh well, I sincerely hope you have MUCH better luck with them than I do. I can never get them to grow.. and if they do, they never grow into the rose they're supposed to be! Depending on your weather (I'm still battling winter here), I'd feed it about 2-3 weeks after putting it in the ground. And since you have just a few roses, I'd use this stuff.
https://www.amazon.com/dp/B000UGUWZM/ I've used that stuff before & it works GREAT. I sprinkled it on my roses after I planted them (2gal roses, not bodybags), and then didn't have to feed again until mid summer. But, I don't use it now 'cuz I have too many roses & would go through 10-15 bottles trying to feed them all!
Roses are like Lay's Potato Chips. Can't have just one!
(& BTW, beautiful whiteface 'tiel!! I miss my 'tiel...)