American elderberry shrubs are prized for their beautiful flowers and fruits, but curled leaves can be concerning for any gardener. If your elderberry shrub’s leaves are curling or distorting, it’s a sign of an underlying issue that needs attention. In this article, we’ll explore the most common reasons for curled elderberry leaves and how to get your shrub back to health.
Environmental Stresses
Environmental factors are one of the top causes of leaf curl in elderberry shrubs Here are some common environmental stresses that can lead to curling
Temperature Extremes
Elderberries don’t tolerate temperature extremes well. In intense heat, leaves can curl and crisp to prevent excess water loss. Similarly freezing temperatures can damage cell walls causing leaves to curl up.
To prevent temperature stresses, provide shade in summer and insulation like burlap in winter. Grow your shrub in a microclimate with moderated temps.
Excessive Wind
Strong winds batter leaves, which causes them to curl. Shelter your shrub from gusts, especially while young. Stake large shrubs if needed.
Intense Sun
Too much sun scorches leaves, causing dehydration and curling. Give your elderberry partial shade, especially in hot climates. You can also drape a sheer shade cloth during peak sunlight hours.
Irregular Watering
Inconsistent watering confuses plants, causing stress and odd growth like leaf curling. Establish a regular watering routine based on your climate, soil and shrub size.
Poor Drainage
Excess moisture from poor drainage or overwatering can lead to root issues that manifest as leaf curling. Improve drainage and allow soil to partially dry before soaking again.
By modifying the environment, you can prevent and alleviate many stresses that cause leaf curl in elderberries.
Pest Problems
A variety of pests are attracted to elderberry shrubs and can cause extensive leaf damage. Watch for these common culprits:
Aphids
Tiny sap-sucking aphids cluster on the undersides of leaves, causing them to distort and curl. Knock them off with a strong stream of water or use insecticidal soap sprays.
Spider Mites
Microscopic spider mites form webs on leaves and extract the juices, causing stippling damage and curling. Wipe leaves with a damp cloth or use neem oil to smother them.
Japanese Beetles
These metallic green beetles skeletonize leaves between veins, leaving lacy damage that distorts leaf shape. Pick them off by hand or use neem oil to deter them.
Caterpillars
The larvae of moths and butterflies chew on elderberry leaves, causing ragged holes and abnormal curling. Remove them by hand or apply Bacillus thuringiensis (BT) treatments.
Regular monitoring helps catch pest problems early before they cause excessive leaf curling damage. Target treatments to affected areas to control infestations without overusing pesticides.
Disease Issues
Fungal and bacterial diseases can also lead to curled, distorted leaves:
Powdery Mildew
This fungal disease coats leaves in white powdery patches, causing distortion. Improve air flow and avoid overhead watering. Remove affected leaves promptly.
Leaf Spot
Bacterial infections create dark, water-soaked spots that can spread, curling leaves. Cut off and destroy infected leaves. Disinfect tools after pruning to prevent spread.
Rust
Rust fungus causes yellow-orange blisters on leaves that can curl them. Fertilize appropriately and remove diseased leaves. Avoid overhead watering.
Good cultural practices are key to preventing diseases. Ensure proper sunlight, air circulation, and pruner sanitation when issues arise.
Improper Care
Sometimes our own care practices can inadvertently cause leaf curling:
Under or Over-Fertilizing
Insufficient nutrients cause deficiency symptoms like curling. Conversely, excessive fertilizer can burn roots and leaves. Have soil tested to determine needs before amending.
Drastic Pruning
Removing too much growth at once stresses elderberry shrubs, which can show up as curled leaves on remaining stems. Prune judiciously just after harvest season.
Damage from Herbicides
Drift from lawn chemicals like 2,4-D can twist and curl leaves. Use extreme caution when applying weed killers nearby, even if dormant.
With proper, consistent care you can avoid many cultural problems that lead to leaf curling in elderberries.
Corrective Care for Leaf Curling
If your elderberry shrub is already showing signs of leaf curling, prompt action can get it back on track:
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Assess watering needs and adjust routine accordingly – let soil dry between waterings.
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Apply a balanced organic fertilizer to correct any nutrient deficiencies.
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Monitor for pests and treat promptly with appropriate methods. Neem oil works on many.
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Improve air flow and sunlight exposure to affected shrubs.
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Prune out diseased portions and sanitize tools afterwards.
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Add nutritious mulch around shrubs to regulate soil moisture and temperature.
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Consider providing temporary shading if heat or sunlight is excessive.
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Ensure proper drainage – relocate shrub or amend soil if it stays waterlogged.
With quick diagnosis and targeted correction, you can get your elderberry leaf curl under control and your shrub thriving once again. Consistent care tailored to your environment is key for long-term health.
Maintaining a Healthy Elderberry
Prevention is the best defense against leaf curling issues. Here are proactive tips to keep your American elderberry shrub happy and healthy:
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Choose an appropriate growing site with proper sunlight, space and drainage.
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Prepare the soil well with compost and adjust pH to suit elderberries.
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Provide supplemental water during dry periods, especially while establishing.
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Mulch annually to conserve moisture, suppress weeds and moderate soil temp.
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Fertilize each spring with a balanced organic product formulated for shrubs.
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Prune judiciously in late winter to shape and remove dead branches.
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Monitor weekly for pests and promptly treat any found with gentle, targeted methods.
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Promote good air flow and avoid excess shade to deter fungal diseases.
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Shelter shrub from harsh winds, especially when young or in exposed sites.
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Protect from extreme cold and heat with season extenders like burlap or shade cloth as needed.
With proactive care, you can have a lush, healthy elderberry shrub with minimal leaf curling issues. Pay attention to its needs and intervene promptly when problems arise. Your efforts will be rewarded with bountiful blooms and fruit production for years to come. Let those elderberry leaves unfurl freely as a sign of your green thumb skills!
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Growing elderberry in the garden
Updated from an original article written by Jeannie Nichols.
Identify the right conditions and potential pests before selecting elderberry for your smart garden.
Photo 1. A purple leafed variety of elderberry foliage with white florets. Photo by Jean Persley.
Aesthetics, jam, pie, wine and medicinal use are among the reasons Michigan gardeners include elderberries (Sambucus canadensis) in their garden. Along with its human benefits, the fruits are a food source for birds. Elderberries are wind-pollinated, but their flowers attract butterflies and other floral-visiting insects.
Elderberry is a native plant growing bush-like to heights of 6 to 12 feet, depending on site conditions (Photo 1). Each bush sends up many canes that flower and fruit, primarily in their second and third years. The tiny purple elderberries generally become ripe in late August (Photo 2).
Photo 2. Elderberry fruits. Photo by Patrick Byers, University of Missouri Extension AF 1017-2012.
Smart conditions suitable for growing elderberry
Elderberry grows in medium to wet soils and can tolerate clay soils if there is good drainage. If you have poorly drained soils, try planting on a berm to increase the chance of success. This plant tolerates full sun or partial shade, requires soil pH between 5.5 and 6.5, and can grow across much of Michigan being hardy through USDA Zone 4a.
Plant elderberry in spring after the final frost using bare root one-year old plants. To avoid competition, remove perennial weeds from the planting area. In the first year, remove flowers after blooming to enhance root growth and structure instead of fruit production. Do not add fertilizer at planting time, although an annual application in later years will assist fertility. If you are unsure whether your soil conditions are appropriate for elderberry production, get a Michigan State University Extension Home Lawn and Garden Soil Test to determine the necessary nutrient and organic matter needs.
Elderberry spreads through root suckers, and these should be pruned in late winter to avoid populations that naturalize over a large area. Though plants do not require annual pruning for fruit production, an annual or biannual pruning of older and damaged stems will help produce new growth from which fruits will be produced. Struggling elderberries can be pruned completely to the ground. While this lengthens the time of fruit production, it removes diseased stems that could be the cause of decline. As new elderberry cultivars are introduced, it is best to confirm with the fruit supplier whether the plant is tolerant of a complete pruning.
What Causes Leaf Curl? – The Garden Sage 10
FAQ
Why are my shrub leaves curling?
How often should you water elderberry bushes?
How do you treat elderberry borer?
Why are my elderberry leaves turning yellow?
Elderberry bugs are only half of the difficulty. It becomes more complicated when we spot elderberry leaves turning yellow. Without healthy plants, we can’t harvest the berries and use them to support our immune system. The two most popular types are Sambucus nigra and Sambucus canadensis, and there are a few different elderberry plant cultivars.
What pests eat elderberry plants?
Some of the most common pests that you find on elderberry plants are cane borers, aphids, and thrips. These are all winged insects that feast on the leaves of your plants. Some are more challenging to spot than others, so make sure you check the underside of the leaves.
Are there any elderberry problems?
Unfortunately, there are a few elderberry problems that you may come across during your gardening journey. Elderberry bugs are only half of the difficulty. It becomes more complicated when we spot elderberry leaves turning yellow. Without healthy plants, we can’t harvest the berries and use them to support our immune system.
Do elderberry plants have bugs?
Don’t panic if you notice a couple of elderberry bugs hanging out on your plants. These are typically easy to remove with pesticides or avoid altogether with floating row covers. Some of the most common pests that you find on elderberry plants are cane borers, aphids, and thrips. These are all winged insects that feast on the leaves of your plants.