How to Prune Overgrown Bushes
Do you have any overgrown shrubs that are touching the house, interfering with the walkway or just plain too big? Before you consider removing the shrub, try rejuvenation pruning.
There are two types of rejuvenation pruning. Extensive rejuvenation pruning is cutting the shrub to a height of 4-12 inches. The shrub will immediately start growing new, healthy, vigorous shoots.
If you don’t like this drastic approach, there is a second type of rejuvenation pruning called gradual rejuvenation pruning. Over a period of three years, you gradually remove 1/3 of the oldest stems every year until you have a fully rejuvenated shrub. This method takes longer to complete but will leave you with a shrub that stays more attractive throughout the rejuvenation period. Using both rejuvenation pruning methods will leave you with the same result; a new, vigorous, healthy plant which can be easily maintained in its natural form. Most of the shrubs that respond well to extensive rejuvenation pruning will also respond well to gradual rejuvenation pruning.
There are a few things to keep in mind with rejuvenation pruning:
- Not all shrubs respond well to this type of pruning. Avoid rejuvenation pruning to junipers, boxwood, and shrubs that have only one primary trunk.
- Spring flowering shrubs won’t flower the year the rejuvenation cut is made.
- Timing is very important. Rejuvenation pruning can be performed with some shrubs right after flowering, but the best time is late winter, right before the plant starts to bud.
- Additionally, pruned shrubs should be watered and fertilized due to stress and shock.
Rejuvenation pruning and renewal pruning are two techniques that can reduce the size and volume of many shrubs without unduly harming them. Which is more appropriate in a given situation will depend on the plant species, the shrub’s function in the landscape, and the wishes of the property owner.
Shrubs are an important part of landscaping. They are used to create privacy, establish borders, and provide interesting foliage and flowers. We find too often, shrubs are planted and then allowed to grow with little or no management except a periodic shearing. Eventually, many shrubs grow too big for their original site. Now that winter is over, we see them everywhere we look… big, unruly, overgrown shrubs.
Rejuvenation pruning is the more severe of the two techniques, and not all species can tolerate it. Plants that are in poor health may not survive this severe pruning. Rejuvenation pruning is the practice of cutting off all old branches at or near ground level. Healthy shrubs will respond by sending up multiple new shoots. These new shoots will need to be thinned to reduce competition and maintain the natural form of the shrub. One benefit of rejuvenation pruning is its immediacy; when the job is done, that ugly overgrown shrub is literally gone. This is, of course, also a drawback since what is left behind is an unsightly stump, at least until new growth ensues.
Renewal pruning is the gradual approach to pruning an overgrown shrub, but it takes many years. In renewal pruning, one-third of the shrub is cut back over the course of three years by using thinning cuts back to the crown or main stem. This approach will maintain the overall shape of the shrub while reducing its volume and height over time. As light is allowed to penetrate the canopy, many new shoots may be initiated. As in rejuvenation pruning, these new shoots will need to be thinned. Although renewal pruning takes longer to complete, the visual impact on the landscape is much less than rejuvenation pruning.
Avoiding the problem of overgrown shrubs is easy to do. Don’t force a plant that gets 6’ tall to be 3’ tall. Research how tall and wide the shrub will grow and plant in an area appropriate for that sized plant. Maintain the size of the shrubs using thinning and heading cuts as needed to manage shrub growth, size, and health.