Topiary is an art-form for the advanced landscaper, but a simple formal hedge can be attained by any novice gardener willing to give a little extra care and attention.
Preparing The Soil
To get the dense green growth typical of the traditional formal hedge, your will need well drained, nutrient-rich soil. Cultivate a trough about four feet wide and 18 inches deep. Mix in rich organic matter like peat or a nice dark compost. Because your hedge will be in place for decades, amending the soil will a large amount of future work.
Training and Trimming Your Formal Hedge
Once your shrubs have grown together into a thick hedge, you will only have to trim them a few times a year to maintain the perfect hedges.
If you have planted a fast growing hedge of thujas or cypress, trim the hedge to the desired shape the first winter. If you are trying to achieve a thick boxwood hedge, shape the sides, but allow the top to grow – trimming new growth will hinder the shrub from reaching the desired height. For a nice dense hedge, always shape your shrub to be a little wider at the bottom than at the top, allowing light to reach all of the visible leaves.