Vine Has No Berries indicates the Need for Male And Female Plant.
The male and female flowers of bittersweet are produced on separate plants. Both male and female plants are needed for fruiting. If there are plants of both sexes and still no berries appear in fall, the plants are probably too far apart. Move them closer together.
Leaves Yellowed; Bumps on Leaves, Stems means Scale.
Scale insects are the most common pest of bittersweet. They gather in clusters on the leaves and stems and look like small bumps. The males are white and elongated; the females, brown and oval. They make bittersweet foliage turn yellow, and eventually drop. Caught early, an infestation can be scraped off vines with a fingernail or a cotton swab dipped in rubbing alcohol. Spray heavily infested plants with a mixture of alcohol and insecticidal soap every three days for two weeks. Add 1 tablespoon rubbing alcohol to a pint of commercial soap spray. Spray vines with chronic scale problems with "superior" type dormant oil in late March. This should smother any over wintering scale pests. For more information see file on Controlling Scale.
Sticky Froth on Stems and Leaves due to Two-Spotted Treehoppers.
Spots of white froth on the stems and leaves of bittersweet signals the presence of the female two-spotted treehopper. The adult treehopper looks like a tiny black thorn about 1/4 inch high, as it sits on the stem of the bittersweet. The female lays her eggs on the plant and covers them with a frothy substance that in itself does no harm. But once these eggs hatch, the emerging nymphs suck the sap of new leaves around them, and then the adults move around freely, also sucking foliage sap. Treehoppers are only a problem on bittersweet when their numbers become high. To control these pests, spray infested vines in late winter with a dormant oil spray to smother the eggs. When spring arrives, look for nymphs. They are less than 1/4 inch long and spiny, and they jump when disturbed. If they are visible, spray them with pyrethrum every three to five days for three weeks. Spray late in the day to avoid harm to honeybees and other beneficial insects in the area. For more information see the file Controlling Leafhoppers.
Vine Growth Stunted, Distorted indicates Aphids.
Once in awhile aphids attack bittersweet vines, clustering on tender new shoots and leaves to suck juices from plant cells. These pests are pear-shaped, fleshy insects, no larger than the head of a pin. Their feeding causes the new vine shoots to curl and leaves to pucker and turn yellow. Try dislodging them with a forceful water spray. If that does not work, spray visible aphids with insecticidal soap spray every three days for about 2 weeks. Insecticidal soap products with pyrethrum added are even more effective for serious infestations. Use every three days for two weeks or until aphids are gone. For more information see file on Controlling Aphids.
Whitish Powdery Coats Leaves due to Powdery Mildew.
Bittersweet is susceptible to fungi which attack their leaves, coating them with a mold that kills them. These fungi thrive in both humid and dry conditions. Badly infected leaves become discolored and distorted. The leaves drop off. Spray infected plants thoroughly with wettable sulfur once or twice a week until the problem subsides. Prune very dense vines to allow good air circulation in and around the plant, and collect and discard all aboveground plant debris in the fall. For more information see file on Controlling Fungal Disease.
Leaves Show Dark Spots means Leaf Spot.
Several fungi cause bittersweet leaves to develop dark spots or blotches. Serious attacks cause vines to look unsightly and interfere with their ability to flourish. Pick off any spotted leaves as they appear and discard them in the trash to prevent the spread of the fungus. Clean up any fallen leaves for the same reason. Spray foliage with a copper fungicide to prevent heavy infections. Read the label and follow the instructions. For more information see file on Controlling Fungal Disease.