Part of the honeysuckle family, the elderberry (Sambucus spp.) is a deciduous shrub-like tree that produce edible berry-like fruits. Elderberries are usually pest- and disease-free, rarely succumbing to debilitating infestations. However, sometimes elderberries can suffer from diseases like cankers, leaf and stem spots, and heart rots, as well as from pests like soft scales, borers and aphids. Elderberry shrubs can also be affected by nutritional deficiencies and excesses, as well as under- and over-watering.
Identify nitrogen and iron deficiencies in your elderberry plants by looking for stunted growth, yellowing leaves, and leaves, flowers and fruits that are undersized and develop later than normal.
Look for wilted foliage, leaf drop and leaf discoloration to diagnose under-watering. Identify over-watering problems by looking for root rots, unusually small leaves, as well as twig and limb dieback.
Identify canker diseases in your elderberries by looking for discolored sunken or callused woody tissues, as well as yellowed or browning wilted foliage on infected branches.
Diagnose wood-rot fungal diseases in your elderberries by looking for mushroom-like growths at the base of the shrub and on bark wounds. Feel the wood around these areas, which may be crumbly and decayed.
Look for discolored spots or blotches on the elderberry leaves to diagnose leaf and stem spots. Caused by a fungus, leaf and stem spots produce irregular patches that are usually yellowish or brown.
Spot the symptoms of aphid infestations by looking for yellowed, curled and distorted leaves. Aphids also secrete a sticky liquid substance called honeydew, which can induce sooty mold growth on the foliage.
Identify a soft scale infestation, particularly by the European fruit lecanium. Both aphids and soft scales produce honeydew and can cause yellowed or curled leaves, but soft scales also can cause the bark to crack and seep a gum-like substance, as well as cause reduced plant growth, discolored rings in fruit, leaves or stems and premature leaf drop.
Study your elderberry plant for stains and holes in the bark that seep a liquid substance to identify longhorned borer infestations. Longhorned borers tend to attack damaged or weakened shrubs and trees, causing branch dieback and discolored, wilted foliage.