Salmonella-Shigella plates. Salmonella-Shigella (SS) plates are used to detect bacterial contamination on raw meat. Salmonella-Shigella agar plates contain lactose, bile salts, ferric citrate, and neutral red.The bile salts select for Gram-negative bacteria.almonella-Shigella plates. Salmonella-Shigella (SS) plates are used to detect bacterial contamination on raw meat. Salmonella-Shigella agar plates contain lactose, bile salts, ferric citrate, and neutral red.
The best time to prune them is in early spring, just before they put on their growth spurt. You can do minor shaping and pruning at other times of year, too. Test Garden Tip: Save on holiday decorations by snipping a few branches for winter holiday greenery.
Crabapple Trimming Schedule. The best time to trim (prune) a crabapple tree is in early spring, before the tree flowers and before new growth begins. Don't worry about interfering with flowering--provided you don't over-prune, your tree will still develop plenty of blossoms from the branches you leave.