Determine the shape that you would like your rosemary plant to take. Tuscan blue can be made to look bushy or even shaped to resemble trees, depending on how they are pruned.
Think about which branches should be pruned based on the shape you want your rosemary plant to take. If you want a bushy plant, you should trim roughly 1/3 of the top branches off in order to encourage more horizontal growth. If you want your plant to take on a tree-like shape, prune the bottom branches close to the trunk and leave the top branches alone.
Prune your rosemary plant in the early evening so that it has time to recover before the next day. Water it prior to pruning and then gently prune it using you garden clippers. You should clip branches at roughly a 45-degree angle.
Mist your rosemary plant with water once you have finished pruning it, concentrating on the areas you cut most. Observe you rosemary plant as it grows and continue to prune every week or two in order to keep the shape of your plant neat and tidy.