In addition to proper planting, watering, and fertilizing; pruning is an important practice for promoting plant health and enhancing the natural size and shape of landscape plants. Pruning is easy—a basic understanding of plant growth, and a few simple techniques, and you’ll be ready to go.
Well pruned shrubs and trees are a hallmark of a carefully tended yard or garden. Foundation plantings are lush and full, and blooming shrubs display their blossoms on shapely branches that accentuate each plant’s unique style.
Most pruning tools have an arc-shaped blade, which makes short work of slicing through small branches. “Scissor action” pruners involve two sharp blades sliding past each other “Anvil cut” pruners have one blade slicing against a wide, flat surface. While scissor action pruners are more expensive, they usually make the cleanest, closest cuts.
Hedge clippers have long, straight blades. They are used for cutting small, green branches and tips and are best reserved for shearing formal hedges. Pruning saws come in a variety of shapes and sizes, with blades designed for larger branches and small trunks.
Make sure blades are kept sharp and oil them periodically. To prevent the spread of plant diseases, clean and disinfect pruning tools after use.
Spring-flowering shrubs, such as these, should be pruned immediately after blooming:
- Chinese Redbud
- Fringe Tree
- Mock Orange
- Spiraea (early varieties)
- Mountain Laurel
- Syringa (Lilac)
- Japanese Quince
- Star magnolia
Shrubs that bloom in summer and fall, and shrubs are grown primarily for their foliage, can be pruned in early spring, before growth starts:
- Callicarpa (Beauty Berry)
- Spirea (late varieties)
- Crape Myrtle
- Buddleia (Butterfly Bush)
- Shrub Althea
- Chaste Tree
- Ilex (Holly)
The soft, green growing tip of a branch is called the “terminal bud.” This bud produces a hormone that affects the growth of side branches. The biology of basic pruning is simple: if you remove the terminal bud, the lateral buds below your cut will be stimulated to grow into more branches. If you leave the terminal bud, the branch will grow longer instead of thicker.
Choosing the Branches
Start by removing any of the branches illustrated below that don’t belong.
Next, look at your shrub with a critical eye while considering the following questions:
- What are this shrub’s natural size and shape (rounded, arching, tree-like)?
- What is the design purpose of this shrub (hedge, foundation planting, specimen plant)?
- Does the plant growth need to be influenced to achieve that purpose?
- Is the shrub healthy and growing evenly?
A well-pruned shrub looks natural, and in most cases doesn’t look like it has been pruned at all. If a shrub’s natural shape does not suit your taste or needs, consider moving it and planting one that is better suited for that location.
Making the Cuts
There are five basic techniques for pruning shrubs. Most pruning jobs will involve a combination of techniques.
- Pinching back: Simply use your fingers to pinch off the terminal bud of the branch. This will encourage lateral branches to form and can be a great way to prevent more pruning later on.
- Heading back: This method removes the terminal bud, resulting in more branches. Cut the branch at an angle, about ¼” above a branch bud and sloping down and away from the bud. The branches about 6” to 8” below your cut will be stimulated the most, so keep that in mind when choosing where to cut. The bud nearest the cut determines the direction the branch grows, with the outward-facing bud usually resulting in the best shape. If a heading cut is made in the middle of a branch with no bud, the result will be a flush of growth at the site of the cut.
- Thinning: Thinning involves removing branches while leaving the terminal bud. Make the cut just outside the branch collar, which is the bulge where the branch meets the stem, but don’t leave a stub. Thinning can produce a more open, shapely plant, without altering its overall size, shape, or growth habit.
- Renewal or rejuvenation pruning: Renewal pruning involves removing the oldest stems and branches at the base, then thinning or heading back the younger stems to promote regrowth. With rejuvenation pruning, the entire shrub is cut to stubs less than 12”. This drastic measure is usually done if a shrub has become an overgrown, tangled mass that is not blooming well.
- Shearing: Shearing involves trimming off the tips of branches and is best used only for formal hedges. Shearing alters the shrub’s natural shape and promotes thick growth only on the exterior of the plant, which results in dead foliage and lack of growth on the interior branches.
For most shrubs, pruning is a forgiving task – once you learn how each plant grows, you can correct previous pruning mistakes as you go. With a little practice, pruning becomes intuitive and is a quick way to revitalize your yard or garden.
Thanks for the great post. The pictures help a lot!
I agree with the previous poster..this was a greatly informative…and yes, the pictures really help!
This is really great info. Well done! A very thoughtful approach. I always feel like I’m randomly hacking at the plants.
I have a doubt. I have muringa plants at home at flowering stage. After flowering there are small fruits getting formed and then both flowers and fruits fall off from the plants. I enquired with a researcher abroad and was advised to apply NAA (napthaleneacetic acid) one ml mixed with 5 liters of water. When I called the local home depot and all American home center they don’t carry this chemical. Could you pl suggest how I can get this or is there any other way to make the plants retain the flowers and fruits till the ripen to the extent necessary for consumption? By the way I live in Los Angeles, CA. Thanks for your help
Your diagram “Choosing the Branches” has water sprouts & suckers backwards. Suckers develop either from roots, or the crown of a plant while water sprouts (epicormic shoots) develop form branches or trunk & are most often the result of excessive pruning.
Thank you, helpful. Especially appreciate the diagrams and photographs.
What should correct height of unknown type of medium leaf hedge be? If same plant that was planted by builder on SE corner of house is on top of valley walkway, would pruning it lower significantly increase water availability for grass?
When is a good time to trim or prune Canadian hemlock ?
I have two different types of Hydrangea. While I cut them back when they get too tall (4′-5′) I have pruned them always in early spring since they are summer bloomers. My lace cap doesn’t flower out as nicely as it did the first few years that I planted it. I prune it very little since it doesn’t get as tall as the larger one that is a ph color changing with larger cluster balls of tiny flowers. This bush grows every year but for the past 3 years, it doesn’t produce any flowers. I prune it to control the growth in early spring before it leafs out as I always have and fertilize but still no flowers. What am I doing wrong? Please advise.
When pruning a two year old hydrangea, am I suppose to do the rejuvenating pruning? As well, my crepe myrtles in order to have them become a bushier shrub, do I trim all lower branches, so to have it develop a trunk like base?
I have both Indian Hawthorn and Ligustrum that are out of control. How
Severely can I prune them and can it be done in the Fall?
Recently read up on hydrangea pruning. Time to prune varies with type of hydrangea. Some bloom on old wood, some on new, and the newest variety out blooms on both old and new wood. So, must know the variety you have to know when to prune, or whether you want to prune at all. Wrong time means no booms, unfortunately.
Thanks for the clear cut (sorry about the pun) description for pruning shrubs. I have been wading through a number of sites, all of which have good information but are hard to follow. Your site makes it clear what to do!
What time of the year, do I prune my hedges and my rose bushes?
We recommend checking out these resources:
Thanks for your question!