In DSM, nicotine dependence is included under the general definition of substance dependence.  The essential feature of Substance Dependence is a cluster of cognitive, behavioral, and physiologic symptoms indicating that the individual continues use of the substance despite significant substance-related problems.
Greenhouse Covering. Whether you're replacing existing greenhouse coverings or building a greenhouse you're sure to find the best greenhouse covering at FarmTek. Greenhouse glazing is the material that covers the greenhouse frame and the most widely used materials are polycarbonate and poly film.
How to Use Greenhouses to Grow Plants From Seeds. 1  Plan to sow seeds in your greenhouse at any time of the year. 2  Soak large seeds, such as beans or tree seeds, in a bowl of warm water overnight before planting them. 3  Fill seed-starting trays with moist potting soil.