The fact that you have to evolve it to attach an energy makes this card pretty unplayable. It takes up bench space, has a bad attack, and requires you to run devo-spray if you want to use it.
The only deck I could see this seeing any play in is Torterra, and even then, Leafeon GX, Lurantis GX, baby Lurantis, Cherrim, and Shiinotic are all better techs.
If the ability read, "Once during your turn, before you attack, you may attach a basic grass energy from your discard pile to one of your Pokemon", this card would be great, even if it said "Once during your turn, before you attack, you may attach a basic grass energy from your discard pile to one of your Pokemon. You may only use one Blessing of the Frost-Covered Trees ability per turn.", this card would still be a good tech, because consistent energy acceleration is a good thing.