Cut back the branches and foliage until you reach the central trunk in the bush.

Aug 11, How to prune to keep spiral evergreens spiral. Trim back the bush above the spiral line in an area about as wide as your fist. Work from top to bottom to create a spiral-shaped depression all around the entire bush.

Oct 02, Join Michele with Art's Nursery in Surrey, B.C. as we share a short tour and a detailed tutorial on what tools you need and techniques to use for pruning you. If you took your existing evergreens and pruned them into trim a spiral bush shapes you would expose inside areas of the plant where there is no growth.

Most evergreens do not bud or grow from old wood with the exception of yews. This means after you pruned the areas showing the trunk would not grow out. Jan 28, This is especially true with spiral form topiary and other more complex shapes and forms. If you allow a topiary to grow too much before giving it a trim, such as a spiral form, the plant will revert back to its natural form, which is a solid column, pyramidal, round or cone shape.

Mar 02, Tie a piece of rope around the center of the shrub. Trim straight across the top of the plant, and when you release the rope you’ll have a perfectly rounded spirea. The two main trimming periods, in early spring and after blooming, are most important to do each year, but you can also trim your spirea as needed throughout any season.