Before the sap starts flowing in the spring, it’s good to prune your plants. If severe pruning is required, this is the time of year to tackle the project. Not all plants can take severe pruning, and flowering plants that have already formed their flower buds will sacrifice their spring bloom if pruned. However, the advantage of early pruning is the maximum re-growth that results, which will fill in your plant beds.
Pruning is an art and the most feared task of homeowners. Many foundation plantings become overgrown due to lack of pruning. Hedges planted as screens may become thin at the bottom because they were not pruned—pruning helps keep them full. Homeowners should worry more about the consequences of neglecting to prune rather than hesitating due to anxiety over how and when to prune. The consequences of not pruning are extensive and costly.
Plants should do what you want them to do, and they need to be trained. Pruning shears should be part of the gear you carry each time you enter the garden. Pruning is an art you learn by doing. A little snip here and a little snip there will do wonders for your plants and your confidence. Always prune to just above a leaf or a break. Use a sharp bypass-type pruner. As you begin to know your plants, you will also learn when and how to prune.
Hedge trimmers should be used to trim hedges and hand pruners should be used to prune the rest of the garden. Most gardeners work with powered equipment: mowers, blowers, and hedge trimmers. But the use of power equipment to prune a foundation planting can leave it looking like something from Disneyland—with formally trimmed shapes rather than gracefully integrated plants flowing together to create an interesting design.
A foundation planting should be pruned with hand pruners. It is an art you may have to learn on your own—or you may choose to hire someone else who is experienced with hand pruners to accomplish this task. There are many little tricks that can be learned when pruning plants—but mostly pruning involves common sense and the understanding of a few growth-related topics. You will learn by trial and error; but remember, the greatest error you can make is not to prune at all. I will try to give you some brief insights and a few basic principles.
Pruning terminal growing points forces lateral branching and usually leads to fuller, more compact plants. The more you prune a hedge, the fuller it becomes. Do not prune too deeply or into the hardwood; rather, prune more frequently. To stop terminal growth, top it. Once you top a hedge, prune it each year to keep it from becoming top heavy.
When I was at Cornell, one spring semester I worked Saturdays at the Cornell Plantations. They had test plots with hedges grown from various plant materials showing the consequences of the various pruning techniques used to create them. I was amazed by the sight of a white pine hedge—narrow but so thickly grown you could not see through it—and it was only nine feet tall. When a pine tree puts out its first growth, cut it back and you will force three new spurts of growth, each helping toward the creation of a very full tree.
Next to my mother’s house we planted a blue spruce tree that could have taken over the parking lot by now. Forty years later, it is a narrow tree flanking the corner of the house. Both customers and horticulturists constantly ask me what the species of this narrow (but full) blue spruce is. When I tell them that it is Picea pungens, “Fat Albert” (a common blue spruce variety), they are in shock. “How did you keep it so narrow?” they ask. Every Christmas, we used its blue tips to make our wreaths and centerpieces. We pruned every tip on the tree every year. The tree grew as a beautiful narrow spiral. The lessons I learned from working on this tree remind me of my college days working on the Cornell Plantations. Great looking hedges don’t just happen; great gardeners create them.
Most Ericaceous plants initiate their flower buds in the heat of summer, developing the buds during the cold of winter and flowering during the warmth of spring. Pruning should take place immediately after they have flowered. In the summer, fall, or winter you may want to take out a branch here or there that has gotten too tall. This is done to maintain the plant’s shape and keep its height down.
Most flowering plants can be treated in a similar manner. Most blue and pink hydrangeas bloom on second-year wood, so prune out only the current year’s growth, but leave all the new growth on the bottom for next year’s flowers. White flowering varieties usually bloom on current season’s growth. Check with your local nursery for varietal differences.
If you are planting shade trees on your property, you will have to prune their lower branches off as they grow, so you can walk, play, and see under them. Tree limbs that are too low often block great views. Severe pruning on overgrown evergreens, trees, and shrubs should take place in early spring, allowing the plant a chance to rebound during a season of growth. Most flowers will not bloom the year that this is done. Before you prune your plant back severely, check to see if your variety will tolerate it.
Photo courtesy of Kevin Tuck