Before you try to turn a disorderly hedgerow into a row of formal hedges, there is one valuable thing to remember. Transforming those messy hedges into a nice row of formal hedges will probably take more than one season and many, many pruning sessions. Be patient, you will not achieve your goal in one pruning, and usually not even in one complete season. The branches of your natural hedge shrubs have become used to growing a particular way, and it will take time to train them to grow another way.
Knowing the right times to prune your bushes will definitely help with your formal hedge. Depending on the kind of hedges you have, you should prune your hedges either in late spring, after they are done flowering, or in late fall, right before they go dormant. On the other hand, with some evergreen hedges, it is best to prune them when they are dormant. Do some research, with the help of your local nursery, about the particular kind of hedges you have before deciding when to prune them.
Experts will recommend using long bladed hand shears for turning those wild hedges into formal hedges. Using long bladed hand shears will enable you to give your hedges a precise cut, and carefully thin and cut out the necessary branches. When shaping the hedge, start by trimming off less than you think necessary. Step back and take a look as you proceed. Remember, once cut, there is no putting it back. Just like a bad haircut, it will grow again, but do you really want to wait that long?
The first step in trimming an unruly row of hedges into a row of formal hedges is to thin out all the dead branches, as well prune out any tangled branches and branches that are unsuitable for any reason. Starting with the dead branches, remove them completely. Move on to the crossed branches, cutting them completely off as well. Trim them right down to the ground.
After thinning out, move to the top. You may have an idea about how tall you ultimately want your row of hedges to be, but you should never take off more than six inches in the first pruning. Once the hedges are close to the ideal height, you should quit, and let them grow for a month or two. It is not a good idea to overdo the first cut.
Once the top is done, trim the sides of your hedgerow to make a flat plane. It helps to trim the hedges so they are slightly wider at the bottom than they are at the top. This is because it will help promote leaf production from top to bottom, rather than from bottom to top. When you prune your hedges a second time, remove the wild ends, but try to leave as much of the new growth as you can for a more formal look.
At some point the hedge will reach the desired height and width, but be patient. Following the right pruning procedures, using the right tools, and knowing the right times to prune your hedges all contribute to the success you will have with formal hedges. Also, remember it will not happen in one pruning session, and sometimes can take more than one season.