Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Really works

I bought three climbing Don Juan roses by mail and one was doing OK, but the other two refused to grow much . I tried slow-release rose fertilizer and nothing happened. When I applied the miracle gro rose plant food there were new leaves in two days, and in 1 week each plant went from about 12 inches high to 18 inches ! They grew as much in 1 week as they'd grown the previous 2 months! This was truly amazing.(I tried it on other more mature roses and did not get any amazing improvement, although theykept growing at a good rate.)