Impatiens are a type of flowering annual or perennial, depending on the climate in which they are grown. There are approximately a thousand types of impatiens available to the backyard gardener, ranging in size from just a few inches tall to over 7 feet. Though impatiens are relatively hardy and low-maintenance, a backyard gardener may occasionally encounter problems with the flowers.
Impatiens require a cool, shady area of your garden in order to thrive. As the seasons change, excessive heat or too much sun can cause the plant to wilt. Wilting is usually noticed in conjunction with a lack of flowers, as the plant ceases producing blossoms to conserve water. Increase watering to keep the impatiens hydrated, and add mulch around the flower plant to help insulate the soil from the sun's heat. In some cases, plants may need to be transplanted to a more shaded area of your yard.
Though rare, impatiens may sometimes be targeted by beetles, aphids and other insect pests that may feed on its foliage and sap. Shooting the plant with a strong jet of water can help knock off pests, though the fragile nature of the impatiens may make this tactic difficult. Mix a homemade solution of 1 qt. water and 2 tbsp. liquid dish soap and spray on the impatiens to kill insects and deter future pests. Alternatively, use a commercial insecticide intended for ornamental flower use.
Fungus or Mildew
While impatiens need cool, moist conditions, excessive moisture caused by overwatering or high humidity can cause fungal rot or powdery mildew growth on its roots or leaves. Prevent fungus on its roots by allowing the soil around the plant to dry out to a depth of 1/2 inch between watering sessions. Kill fungus and powdery mildew on the impatiens' foliage by using a fungicide based on horticultural oils such as neem oil, or a chemical-based formula such as potassium bicarbonate.
Stunted Plant Growth
Young impatiens may be attacked by underground worms called nematodes, which feed on the roots and cause the above-ground portions of the plant to be stunted in growth or turn yellow. Untreated, nematodes will kill the entire plant. Affected plants must be scooped out and discarded, along with all of the soil around its root ball. Sprinkle fish emulsion fertilizer in the area to deter future nematode invasions.