Theres nothing illegal about buying gardening equipment so I dont see how they can use that as evidence for a search warrant... therefore I dont worry.
Yes it is legal but in the past there were many consequences as a result due to Operation Green Merchant - And believe it or not Operation Green Merchant is still in existence but not on a level like it was in the 90s .. Only a few years back a Journalist for the Grand Rapids Press in Michigan was busted by Operation Green Merchant due to his large online purchases ..
Operation Green Merchant
From Wikipedia, the free encyclopedia
Operation Green Merchant was the code-name for a nationwide investigation and operation targeting businesses advertising specialized horticultural equipment that was supposedly used to grow cannabis in the 90's.
The DEA had decided to investigate the advertising inside the High Times with the goal of shutting down the blooming indoor marijuana industry using United Parcel Service records to trace deliveries of indoor growing equipment and seeds.
The three key targets of Green Merchant were the High Times Magazine, Sinsemilla Tips and the Holland's Seed Bank owned by Neville Shoenmaker.[4]