Dying shrubs are one of the most distressing things to deal with in landscaping. Whether it’s a new shrub that is failing to establish or a mature shrub that is starting to fail, there are many causes for shrub death that can be monitored and prevented.
So why are my shrubs dying? Preventing shrub death involves amending the soil and making sure that the shrub is planted correctly, to begin with. Without proper conditions, many shrubs will die. They generally die because of the following:
- Watering issues
- Exposure
- Failure to thrive
- Incorrect environmental parameters
- Pest damage
- Disease
Having to dig up a dead shrub is a serious pain in the neck, but it can often be prevented with a little research and gardening know-how. Read on to find out more about why your shrubs are dying and how to save them.
What Does a Dying Shrub Look Like?
It may not be easy to get to the bottom of why a shrub is dying, but identifying a shrub that is on its way out is not as hard. Here are some of the things to look for when you inspect your yard for dieback i
your shrubs:
- Leaf discoloration: Either yellowing leaves or leaves that wither and turn brown are both signs that a shrub is in decline. Leaf discoloration can either be indicative of dieback or a nutritional deficiency such as iron chlorosis.
- Brown dry spots: This is by far one of the most apparent symptoms of a dying shrub—big patches of dead brown foliage. Unfortunately, this is also a symptom of shrub death once a shrub is very far gone, and many shrubs in this kind of condition may be challenging to save.
- Delayed spring growth: When doing a spring inspection of property trees and shrubs, noting shrubs that fail to put out fresh spring growth can be an excellent way to root out problems with shrubs before they actively start to die.
- Small leaves: A shrub that is under attack from soilborne pathogens, fungi, or insects isn’t capable of producing large leaves because of lack of energy. Like delayed spring growth, smaller leaves can be a more subtle sign of a shrub in trouble.
- Leaf margin scorching: Leaf scorch can be the result of lack of adequate water, and causes the shrub to look like it has been lightly toasted. This is a stage that precedes brown dry spots and shrub death. Leaf scorching can sometimes self-correct with the onset of rain or cooler weather.
- Early leaf drop: One of the earlier signs that a shrub might be faltering is when a shrub begins to lose leaves earlier and earlier each winter.
- Thinning foliage: Another sign of older age or dieback in your shrubbery, thin patches in your shrubs are a sign that environmental conditions are not optimal, your shrubs are approaching the end of their lifespan, or your shrubs are dealing with some kind of problem that needs to be addressed.
It’s essential to recognize the signs of a struggling or dying shrub because the sooner you can tell that a shrub is having a hard time, the sooner you can take steps to solve the situation. If signs of a dying shrub are caught early enough, you may be able to turn it around and save the shrub. If not, you’re going to end up having to dig it up eventually, so it’s best to be preemptive where you can.
Noting the more subtle signs of a dying shrub can be the key to keeping it alive since some of the more pronounced symptoms indicate a shrub that may be too far gone to save.
Why Do New Shrubs Die?
One of the biggest problems gardeners run into with shrubs dying is the death of new shrubs that have just been planted. This can be particularly frustrating since shrubs are both costly to install and a backbreaking project to boot. Nobody wants to have to plant a line of shrubs only to have to dig them all back up again after they fail to thrive.
So what are some of the reasons that new shrubs die? Here are some potential causes:
- Environmental exposure: When young shrubs are raised in a nursery or greenhouse environment, they are often protected from the elements by hoop houses or other coverings. If they are planted during periods of inclement weather such as flash flooding or drops into freezing temperatures, this can put stress on young shrubs and cause them to fail.
- Failure to root: When a young shrub fails to root, this can be the result of overexposed roots that are damaged or dried out. It can also be the result of the shrub becoming rootbound in a nursery pot. If this happens and the root ball is not sufficiently teased out to encourage new growth during the planting process, the roots may die.
- Lack of nutrition: If a shrub is not fed properly during its first two seasons of growth or it is planted in soil conditions that lack organic natural nutrients, a shrub may not survive past its second year. Shrubs must also be planted in an area that receives sufficient sunlight throughout the season.
Knowing what conditions your shrub type requires before installing it, making sure the soil is amended correctly, and planting shrubs when the threat of inclement winter weather has passed will help encourage new growth and prevent young shrubs from dying after being transplanted.
Why Do Mature Shrubs Die?
Even more mystifying than having new young shrubs die after being installed is when mature shrubs that have been doing well for years suddenly go into decline one season. In established shrubs, dieback can be the result of a wide variety of causes, such as:
- Disease: Because they are long-lived, shrubs and trees must battle many different kinds of soilborne pathogens that attack them at the root level where they are most vulnerable. These soilborne pathogens can also be splashed up onto the leaves to cause issues like bacterial wilt and boxwood blight.
- Insect attack: There are several kinds of insects that can cause damage to shrubs either by eating the leaves or attacking at the root level. Some pests that can damage your shrubs are:
- Aphids
- Lacebugs
- Bagworms
- Beetles
- Spider mites
- Tent caterpillars
- Animal attack: Many animals such as rabbits, rodents, and deer like to eat the tender new growth on shrubs, and over time this can cause a shrub to become damaged. Years of this erosion from animal attacks can eventually overwhelm the shrub and cause it to die.
- Age/decline/dieback: In some cases, there is no easily found reason why a shrub is beginning to go into decline, or the environmental conditions are otherwise good. This can sometimes simply as the result of a shrub living out its natural lifespan. Very few shrubs live over a decade, so it is normal for them to eventually die of natural causes if they don’t succumb to other environmental factors.
- Environmental stresses: Several seasons of drought or overwatering from excessive rain can cause damage to a shrub over time, and if a shrub is already wrestling with other environmental issues such as insect attack or disease, these environmental stresses can put them over the edge and kill them.
Mature shrubs die for many reasons, but at least a few of them can be prevented through proper maintenance. The best way to protect your shrubbery is to keep a close eye on them and not problems
early on, so they can be resolved before long-term damage is done to the shrub.
Surprisingly while snails and slugs can be good for grass, some types of shrubs they will feed on causing a decline in shrub health and ultimately can make them die back. Check out an article we wrote here about why snails and slugs can be bad for your yard and how to stop them before it gets worse.
How to Keep Shrubs from Dying
There are strategies that homeowners and gardeners can undertake when it comes to shrub maintenance to make sure that both newly planted shrubs and established shrubs thrive for as long as possible. Here are some healthy practices to make sure your shrubs stay fresh-looking and healthy for years:
- Fertilize seasonally. One reason that older shrubs can start to go into decline is when they’ve leeched the soil around them of nutrients over several years while putting on new growth, they can start to have a hard time feeding themselves as they mature. To combat this, amend the soil around the base of shrubs with shrub fertilizer to replenish lost nutrients. A good time to do this is just before you mulch for the season, we discuss it here.
- Protect shrubs from bad weather. Especially in their first two growing seasons, shrubs can be susceptible to any number of environmental stressors. If below-freezing weather is expected, cover new shrubbery with blankets or plastic sheeting to prevent frost-related damage. Frost is especially dangerous to surface-level root systems of new shrubs.
- Choose shrub locations carefully during planting. Planting a shrub in an area where it has little protection against wind, rain, and cold will make it more difficult for the shrub to become established. Care should also be taken to plant shrubs where the soil has been appropriately amended for aeration and nutritional value.
- Deter pests. There are many environmentally friendly pest deterrents available to drive away everything from beetles to deer that are attacking your shrubbery. If deer are a persistent problem because of your geographic location, a deer fence may be necessary to install around the perimeter of the property to protect shrubs and your vegetable garden.
- Amend the soil. In addition to making sure that the native soil has plenty of nutrients, the soil should also be amended to make sure that it has plenty of drainage to provide aeration to the shrub root systems so that they don’t become waterlogged and develop rot. This is especially important when a shrub is young and trying to establish itself.
Taking care of your hedge throughout the growing season isn’t a difficult task; it’s just not one that can be neglected. Many people nurse their flowerbeds but fail to take proper care of their trees and shrubs until long-term damage has already occurred, and the plant is on its last leg.
It’s a good idea to choose a few days out of the year to go around the yard and take stock of each shrub to check its condition and see what (if any) changes need to be made to keep the shrub healthy. Soil samples can also be collected and submitted to your local agricultural extension to determine the exact profile of minerals and pH available in the native soil.
Once you determine what nutrients are lacking in native soil, it can be slowly built up using compost, fertilizer, mulch, and other organic material until the soil is rich and fertile enough to sustain the shrub for years to come.
Watering and Shrub Death
A significant issue that people run into with dying shrubs is a watering problem.
- If shrubs do not receive enough water throughout the growing season, this can stress the shrub significantly, causing damage such as leaf scorch. A shrub can survive a dry season every few years, but too many dry seasons in a row can put an abundance of stress on the plant.
- On the contrary, another issue that sometimes causes shrubs to die is too much water—the shrub is planted in an area where water saturates the ground and stands after heavy rains. These are the kinds of conditions that can lead to root rot.
To ensure proper watering levels, shrubs should be watered regularly during the hotter parts of the year, and it is a good idea when planting new shrubs to install aeration tubes in the bed where the shrub is being planted. These tubes ensure that the root system of the shrub remains well-oxygenated while it tries to establish itself, and can help prevent root rot as the result of standing water.
Temperature and Shrub Death
Temperature problems are another major cause of dying shrubs that homeowners and gardeners don’t take into account often enough, especially with newly planted shrubs.
- Young plants are tender and vulnerable to environmental exposure. Even mature shrubs can take a severe beating from below-freezing temperatures, especially if they are a more temperate species.
- Scorching temperatures can typically be mitigated by planting shrubs where they will receive midday shade (this is especially important for shrubs that don’t do as well in direct sun).
- When temperatures soar, it’s also a good idea to make sure that shrubs receive extra watering since rain is hard to come by in hot, dry weather.
- Another temperature-related issue to be aware of is temperature fluctuations. This is especially important if you’re trying to transplant young shrubs from either a nursery or your indoor cuttings.
If a shrub is not adequately hardened off through environmental exposure before being subjected to sharp drops or spikes in temperature, the related stress can kill it. This is especially true if the shrub is new and is trying to expend the bulk of its energy just getting established.
Pests and Shrub Death
While shrubs can fend off many attacks from both herbivorous insects and animals, the damage that these pests gradually cause can become overwhelming to the point that the shrub becomes vulnerable to disease. Young shrubs and older, frailer shrubs are particularly susceptible to pest-related damage.
- Insect pests: Insects are one of the more insidious threats to a shrub because shrubs can deal with a lot of insect damage from season to season, but the cumulative effect of an insect infestation can eventually cause a shrub to dieback. Many of the insect pests that attack shrubs are the larval forms of moths and beetles.
- Rodent and rabbit pests: Rabbits, hares, and other rodents can do significant chewing and burrowing damage to the root system of a shrub, especially if they decide to den underneath it. Shrubs can be protected from these pests by installing property fencing or live traps for humane relocation of any animals you catch.
- Large animal pests: If you live in the rural countryside, larger animals may pose a threat to your hedge, like deer, elk, or even roaming livestock such as goats, sheep, and cattle. Large animals can be dealt with by installing proper fencing.
Disease and Shrub Death
Along with insect and animal pests, several types of disease can afflict shrubs and eventually kill them. Here are some of the diseases that attack shrubs:
- Blight
- Powdery mildew
- Leaf spot
- Phytophthora root rot
- Canker
- Rust
- Black spot
Diseases in shrubs can be prevented by practicing proper soil management and treating any affected shrubbery with a transpirant that covers shrubs with a protective coating without interfering with photosynthesis or growth.
When to Replace a Dying Shrub
So, you’ve inspected your yard and discovered a shrub that you think is dying. Should you dig it up, or should you try to nurse it back to health? The answer depends on how far gone the shrub is. There are a few things you can do to test how badly damaged or diseased a shrub is and whether it is capable of regenerating itself.
Sometimes it can be challenging to determine whether a shrub really is struggling or has just died back for the season, as many shrubs are not evergreens.
Scratch Test
One way you can test to see if a shrub still has some life left in it (even if it appears dead) is to scratch away a section of the outer bark of one of the shrub’s branches. If the tissue underneath is dry and brown, that section of the shrub’s branch is dead.
Try scratching away a section of branch closer to the base or heart of the shrub. If you cannot find any live wood in the shrub’s branches (indicated by green tissue underneath the outer bark), then the shrub is probably too far gone to save.
However, if there is green tissue in some of the shrub’s branches (even if sections of it are dying), then the shrub can likely be saved with a little extra care. If a shrub still has life in it, pruning away the dead sections of the shrub and fertilizing it can help give it the extra energy it needs to generate new, healthy growth in the spring. Adjusting water levels can also help give struggling shrubs a leg up.
How to Avoid a Dying Shrub from the Nursery
If you want a hedge of lush, healthy shrubbery in your yard, one of the first things you need to do is avoid bringing home a lousy shrub in the first place. Not only can a sickly shrub be more vulnerable to die-off in the first two growing seasons, but a shrub infected with a disease such as bacterial wilt can also transfer that infection to nearby shrubs once it is planted.
To avoid choosing a lemon from the nursery, follow these tips for choosing a healthy new shrub:
- New growth: Healthy young shrubs should have apparent new growth that points to their rapid development—young shrubs that do not have tender new growth are struggling, not thriving.
- Damage and disease: Avoid bringing home any shrubs that show indications of either insect damage or disease, as these vectors can be transferred to your plants back home. If any indications of disease are seen at a nursery, it is probably a good idea to shop elsewhere.
- Guarantees: It’s always best to work with greenhouses and nurseries that provide a warranty for their shrubs and trees provided that the plants are adequately transplanted. A nursery that offers a money-back guarantee that a shrub will do well is trustworthy.
- Root system: It’s essential to choose a shrub that is not rootbound and doesn’t appear to have more roots than soil left in its pot. Not only does becoming rootbound potentially stunt a plant’s growth and stress it, but it also can prevent a shrub from being able to transplant successfully.
Once you’ve chosen a healthy shrub from the nursery, you should do two things to ensure that the young shrub transplants successfully—soak the rootball overnight in a bucket of water, and gently tease out the root ball to encourage new root growth once transplanted. Root growth hormones can also be applied to the rootball before planting to help accelerate establishment.
What to Do with a Dead Shrub
If you establish that your dying shrub is dead and can’t be revived through maintenance, the shrub must be completely dug up and removed. Merely cutting the shrub off at ground level can leave both unsightly stumps and an accessible location for yellowjackets, paper wasps, and other poisonous yard pests.
If the shrub you are removing from the yard is diseased, it is a good idea to discard the shrub rather than try to compost it. You should not compost diseased plant matter, as these pathogens can then be transferred to new plants when the compost is used in a different location.
To dig up a dead shrub, follow these steps:
- Run a water hose at the base of the shrub for a while to saturate the ground. The harder the ground is, the more difficult a shrub will be to dig up, especially if it is an older shrub with a well-established root system.
- Once you’ve prepared the ground, you can take pruning shears or an electric saw and cut back the shrub until the trunk is revealed.
- Dig a trench around the perimeter of the shrub, using the sharp head of the shovel to cut through any gnarly root systems. Before digging, it is a good idea to make sure there are no water lines or power lines anywhere nearby with the utility company.
How Long Does a Shrub Live?
You might be dismayed to find a dying shrub in your yard, but like all plants, shrubs aren’t immortal. Unlike trees, which can sometimes live for centuries, shrubs have a typical lifespan of seven to ten years, somewhere between a tree and smaller perennials. That means if you’re a homeowner, at some point, you’re probably going to end up replacing a dead shrub.
The lifespan of a shrub depends on both the species of the shrub and the conditions that the shrub is growing in. Shrubs that are living in sub-optimal growing environments will not last as long as shrubs
that are carefully tended year after year.
An important part of property maintenance is taking stock of the trees and shrubs on the property each season and inspecting them for signs of dieback or other problems. If caught early enough, many of these issues can be solved through horticultural husbandry practices.
Dying Shrubs Can Be Prevented
It’s normal for shrubs to decline and die off after a certain age. Still, there are many things you can do as a gardener and a homeowner to both protect the shrubbery present in your property’s landscape as well as safeguard any new shrubs that are added in.
With just a little preventative maintenance performed on your shrubbery from year to year, you can make sure that your shrubs are lush and vibrant for decades.
