As for a young plant it is best to prune or pinch the plant in order to build a full-bodied, well-branched plant. If the plant is leggy when you purchased it, shear the plant back hard by 1/3 to 1/2 its original size. Once it puts on an inch or two of growth, pinch the branch tips to remove just the growing tips, these tips control branching. Once growing tips are removed the buds below it will turn into stems. Once these new branches grow an inch or two, pinch the tips out again. You can repeat this throughout the first growing season as you are tending your garden. Although you will sacrifice blooms, this technique results in a well-branched, full-bodied plant that will have more flowers in subsequent years.