Scale on plants sounds like and looks like a plant disease, but the term “scale” actually refers to an infestation by any one of over 8,000 species of tiny, sap-sucking insects. Scale insects typically adhere to the stems, branches, and sometimes leaves of plants to feed on sap. They have a shell-like bump appearance, which makes it easy to mistake them for a fungal or bacterial disease. Though, the treatment of scale on plants is much different than the treatment for plant diseases, so it is essential to know the difference.
Below, learn about how to identify, combat, and control scale insects on plants both inside and outside.
American beautyberry shrubs (Callicarpa americana) are prized for their vibrant purple berries and attractive foliage that provide year-round interest in the landscape. However, like any plant, they can fall victim to pest problems One common pest that affects beautyberries is scale insects Scales are small sap-sucking insects that attach themselves to stems, leaves, and branches, weakening the plant by extracting nutrients and moisture. Left untreated, a scale infestation can seriously damage and even kill an American beautyberry shrub.
In this comprehensive guide we will discuss how to identify, prevent and safely get rid of scales on your American beautyberry shrubs. With some vigilance and proper control methods, you can keep these gorgeous native shrubs scale-free and thriving.
Identifying Scales on American Beautyberry
The first step in managing scales is learning how to spot the signs of an infestation. Here are some tips for identifying scales:
-
Inspect stems, undersides of leaves, and branches for small bumps or lumps ranging from white, tan, brown to black in color. These bumps are the protective shells that house the adult female scales.
-
Look for sticky sap or a black mold growth on the surface of the shrub. This “honeydew” is secreted by the scales as they feed.
-
Check for yellowing or wilting leaves, premature leaf drop, or dying stems and branches. This can indicate a severe scale infestation.
-
Monitor in early spring and late fall when scales are most active and populations are high.
-
Use a magnifying glass to look for tiny, slow-moving yellow larvae crawling on the shrub. These are scale crawlers that eventually settle and form shells.
Preventing Scale Infestations
An ounce of prevention is worth a pound of cure when it comes to scale management. Here are some tips to help prevent scale infestations in your American beautyberry shrubs:
-
Select disease and pest-resistant beautyberry cultivars like ‘Meadow Muffin’, ‘Kaleidoscope’, or ‘Blonde Ambition’ when planting.
-
Water shrubs at soil level and avoid wetting foliage to discourage scale establishment.
-
Fertilize plants properly to promote vigor and avoid excess growth that attracts scales.
-
Prune out heavily infested stems and branches and dispose of debris immediately.
-
Monitor shrubs frequently and treat early signs of scales before they spread.
-
Use horticultural oils or insecticidal soaps as dormant sprays to suppress overwintering scale populations.
Control Methods for Getting Rid of Scales
If prevention fails and scales gain a foothold on your American beautyberry, taking swift action is key. Here are some safe, effective control methods:
Insecticidal Soaps and Oils
-
Insecticidal soaps and horticultural oils smother and desiccate soft-bodied scales. Spray plants thoroughly, especially under leaves.
-
Use soaps derived from potassium salts of fatty acids for optimal safety. Good options include Safer Brand Insect Killing Soap and Bonide Insecticidal Soap.
-
Neem oil and refined horticultural oils also work well against scales. Monterey Horticultural Oil is an excellent OMRI listed choice.
Systemic Insecticides
-
Systemic insecticides like imidacloprid are absorbed by plants and ingested by feeding scales, providing extended control.
-
Apply as a soil drench or basal trunk spray. Be sure to follow label directions carefully.
-
Avoid using systemic insecticides on blooming plants attractive to pollinators.
Natural Predators
-
Beneficial insects like lady beetles, green lacewings, and parasitic wasps prey on scales and provide biological control.
-
Interplant beautyberries with attractive predator-friendly plants like dill, fennel, and cosmos.
Dormant Oil Sprays
-
Applying horticultural oil in late winter helps smother overwintering scales on branches before they become active in spring.
-
Take care not to overspray and damage berry buds when treating established shrubs.
-
Use a 2% oil solution and coat shrub thoroughly for optimal effectiveness.
Maintain Plant Health
-
Keep shrubs healthy with regular watering, mulching, and proper nutrition to withstand and outgrow scale damage.
-
Remove and dispose of heavily infested branches and stems immediately to prevent spreading.
-
Shelter shrubs from harsh weather extremes that add stress and make them more vulnerable to pests.
While scales can certainly be a nuisance, there are many effective options for controlling them safely and organically on American beautyberry shrubs. The key is vigilant monitoring along with early intervention using insecticidal soaps, horticultural oils, and beneficial insects. Maintaining optimal growing conditions and plant health will also go a long way in preventing scale infestations. With some diligence and the right control methods, you can keep scales from negatively impacting the beauty and vibrancy of your American beautyberry shrubs.
When to Combat Scale
Scale insects are adept at protecting themselves at most life cycle stages. Scale eggs are laid under the females body, so they are shielded by the protective outer coating of the mother insect.
Control measures are most effective during the scale insects “crawler stage”—the nymphs that appear soon after the eggs hatch. At this point, the nymphs have legs and are actively crawling to find new spots to attach and feed. This is the time when they can be effectively killed with pesticides. However, timing is everything, and there is a short window of opportunity.
Because adult scale insects are so firmly attached to their host plant and covered in their armor coating, they can be tricky to exterminate. Sometimes, throwing out infested plants is easier than taking all the steps necessary to try and eradicate the scale. Quick removal can prevent the scale from migrating to surrounding plants. But if this is not practical, several control methods have proven effective against scale.
- Rubbing alcohol
- Horticultural oil
- Insecticidal soap
- Beneficial insects
- Spray pesticide (organic or chemical)
- Neem oil
- Dish detergent
:max_bytes(150000):strip_icc()/how-to-get-rid-of-scale-insects-1402693-07-8b64e8e506df4b2fb23301b98c60e278.jpg)
The Spruce / Almar Creative
Scale Damage
Along with allowing fungal diseases to thrive through their honeydew deposits, scale harms your plant by depleting it of sap, which therefore hinders the plant’s ability to send nutrients through its entire body. Scale also causes cellular damage to the plant, making it structurally weaker. If left untreated, the scale will damage and weaken your plants and, most likely, eventually cause them to die.
The COMPLETE Guide to Getting Rid of Scale Insects
FAQ
How do I get rid of white scales on my bushes?
What kills scale on shrubs?
What is a homemade remedy for scale on plants?
How do you care for a beautyberry plant?
Beautyberry plants tolerate full sun to partial shade, and while they like moist soil, they can tolerate somewhat dry conditions. Enjoyed mainly by wildlife, humans can also consume beautyberries, best served as a jelly. Here are the main care requirements for growing a beautyberry plant: Plant in native soil within beautyberry’s growing zones.
Are beautyberry bushes low maintenance?
Callicarpa americana, the American beautyberry shrub, is a delightful plant that will reward you with stunning purple berries that last through the fall and winter. If you are growing beautyberry bushes in their native region, these plants are low-maintenance.
How do you care for American Beauty berries?
American beautyberries are easy to care for. They bloom and set fruit on new growth each year, so pruning is a breeze in the spring. Just prune the old branches down to 12 inches tall or less, and you’ll have beautiful bright purple berries by Fall on long arching branches that can reach 4 to 7 feet tall in one season.
Can beautyberry berries reseed?
Beautyberry shrubs reseed themselves readily, and the Asian species are considered invasive in some areas. You can easily grow these shrubs from seeds. Collect the seeds from very ripe berries and grow them in individual containers. Keep them protected for the first year, and plant them outdoors the following winter.