Scotts Miracle-Gro ( SMG) has been weed-wacked back down to size by one analyst -- and is withering in morning trading as a result.The garden and law care products supplier was downgraded by SunTrust Robinson Humphrey analyst William Chappell to neutral from buy. Chappell noted the stock is already up 16% this year, but with the garden season ending in July, is not expected to move much higher. Shares of the company opened down 3% to $33.54 on Monday. The company has traded between $16.12 and $39.06 in the past 12 months. While it may not seem like there is much more room for the stock to grow, Jefferies & Co. analyst Douglas Lane upgraded his earnings estimates for 2010. He urged investors to buy shares ahead of the release of third-quarter financial results later this summer, which are expected to show growth from last year. Last month, Scotts Miracle-Gro raised its full-year forecast to $2.35 to $2.45 per share from $2.10 to $2.30 a share. The company said that consumer purchases were up 17% from October to May compared to the previous year, and remained strong in early June.