Do you have a shrub in your yard that has been neglected? Is it in desperate need of some TLC? Wondering what to do with it?

The answer is prune it!

What is Pruning?

• Selectively removing parts of a plant for the benefit of the entire plant.
• Controls plant size and shape.
• Keeps shrubby evergreens dense
• Removes unwanted branches.

Properly pruned plants should look natural. Pruning should be done with care and knowledge.

When to Prune 

Spring-flowering shrubs

You don’t want to cut off next year’s flower buds unless you grow shrubs for their foliage and not their flowers. Spring-flowering shrubs, or those that bloom on last year’s growth. Examples are shrubs such as lilac and forsythia. The best time to prune it is in late winter or early spring (before mid April). Heavy pruning will reduce or eliminate your flower display for a couple of years, but you will end up with a healthier shrub.

Once you have your spring-flowering shrub healthy again, maintain its health by lightly pruning it yearly right after it is finished flowering. Only light to moderate pruning will be needed and as the shrub will have time to recover and grow new flower buds before winter, next year’s flower display shouldn’t be impacted.

Summer-flowering shrubs

Some shrubs flower on new growth.  Those are branches grown during the current growing season. Examples: Japanese spirea and panicle hydrangea. These should be pruned in late winter or early spring regardless of whether you are maintaining your shrub or rejuvenating it.

Inconspicuous flowering shrubs

Some shrubs are grown for reasons other than their flowers. Their flowers may be inconspicuous, but they may have beautiful foliage, fruit, or bark. These shrubs should be pruned in late winter or early spring before new growth emerges.

Evergreen shrubs

Try to prune evergreen shrubs in early April before new growth begins. Examples: juniper and yew.  If you need to prune mid-summer, do so lightly. Avoid fall as evergreen shrubs pruned in fall are more susceptible to winter injury.

How to Prune

Maintenance Pruning

First, remove any branches that are dead, diseased, or broken. These branches are not helping your shrub and could possibly be harming it.

Next, check the structure of your shrub. Look for branches that are crossed.  Rubbing will cause wounds in plants just like humans get blisters. Next for branches that are competing and remove the least desirable one. If there are branches that are growing downward remove them as well. Also remove any limbs along the trunk that are larger in diameter than the trunk itself.

Finally, remove any suckers or water sprouts. Suckers are shoots that are coming up from the roots or low on the trunk that are vigorous in nature. Water sprouts are vigorous branches that grow vertically. Both suckers and water sprouts are weakly attached to the plant. This means they can become problematical. These weedy branches can crowd desirable branches.  This will reduce flowering and fruiting. They can also change the plant’s structure making it prone to wind and ice damage.

Pruning for Rejuvenation

Rejuvenating a shrub takes time and a lot of patience. It will take three years to rejuvenate most shrubs and is not a quick fix.

The first step is to remove any dead, diseased, or broken branches. Nothing good will come from them.

Next, look at your shrub’s oldest, thickest trunks or stems. Prune out one third and ONLY one-third to the ground. This will encourage your shrub to put out new stems from its roots. Repeat this same process for the next two years. If each year you remove one third of the largest and oldest stems.  After three years you should have removed every original stem from the shrub.  Once all of the old, overgrown trunks are removed, switch back to maintenance pruning.

Rejuvenating cane-growth shrubs

Examples: spirea, forsythia, or honeysuckle have many stems or canes. If the shrub is healthy but overgrown rejuvenation can happen in a shorter time frame. Do this by cutting all the canes back as close to the ground as possible in early spring. The flowers for that season will be sacrificed.  However, the shrub will grow back within a growing season and look as good as new. Only use this method on cane-growth shrubs.

Resources

https://www.extension.iastate.edu/news/yard-and-garden-knowing-when-prune-shrubs

https://extension.umn.edu/planting-and-growing-guides/pruning-trees-and-shrubs

https://extension.unh.edu/blog/2021/02/can-water-sprouts-suckers-be-prevented-trees