Insecticide For Gardenias

When you want to buy some insecticide for gardenias, there are certainly a number of items to consider. For example, there is a spray on insecticide for gardenias that you can apply with a sprayer or the more traditional granules of insecticide for gardenias. The question of what is more effective will depend on various variables such as the type of gardenia and whether it blooms indoors or out.

Insecticide For Gardenias

With their wonderfully fragrant blossoms and lustrous, dark green leaves, gardenias (Gardenia jasminoides) are popular shrubs with many southern gardeners. Their positive qualities compensate to a large extent for the fact that gardenias are somewhat high-maintenance plants with fairly specific cultural requirements. To learn more about growing healthy gardenias, see HGIC 1065, Gardenia. In addition to problems resulting from improper growing conditions, gardenias are also susceptible to several diseases, insect pests, and other problems. For information on diseases and other problems that affect gardenias, see HGIC 2058, Gardenia Diseases & Other Problems.

Insect Pests

Whiteflies: Whiteflies are not true flies but are more closely related to scale insects, mealybugs, and aphids. They are very small – about 1/10 to 1/16 inch long. They have a powdery white appearance and resemble tiny moths. When at rest, the wings are held at an angle, roof-like over the body. The immature stage is scale-like and does not move. When plants that are infested with whiteflies are disturbed, the whiteflies flutter around briefly before settling again.

Both adults and immature forms of the citrus whitefly (Dialeurodes citri) feed by sucking plant sap. The damage that they cause is similar to that caused by aphids. The infested plant may be stunted. Leaves turn yellow and die. Like aphids, whiteflies excrete honeydew, which makes leaves shiny and sticky and encourages the growth of sooty mold fungi. See Sooty Mold section in HGIC 2058, Gardenia Diseases & Other Problems for detailed information.

Control: Insecticidal soap or horticultural oil sprays are effective against whiteflies, but the plant must be sprayed thoroughly so that the soap or oil contacts the insects on the underside of leaves. Repeat spray three times at 5 to 7-day intervals. Foliar injury from soaps and oils may occur on plants under drought stress. Water the plants well the day before spraying. Only apply horticultural oils or insecticidal soaps if temperatures are below 90 °F, and apply very late in the day to prevent foliar injury.

Apply horticultural oil sprays when there is no rainfall in the forecast for the next 24 hours.

If stronger insecticides become necessary, products containing pyrethrin, bifenthrin, cyfluthrin, permethrin, cyhalothrin, esfenvalerate, or acephate can be used. Acephate is a foliar systemic insecticide and may provide better control than the other contact spray insecticides. Soil-applied insecticides, such as imidacloprid or dinotefuran, can give season-long control of whiteflies. These are applied as a soil drench or as granules, which are watered into the soil. Soil-applied insecticides are most effective if applied in spring as new growth appears. See Table 1 for products that contain these insecticides.

Scale Insects: Various scale insects feed on gardenias, including the soft scales – Japanese wax scale (Ceroplastes japonicus) and cottony cushion scale (Icerya purchasi); and the armored scales – tea (Fiorinia theae), greedy (Hemiberlesia rapax), and oleander scales (Aspidiotus nerii).

Scales are unusual insects in appearance, and as a result, are sometimes misidentified by gardeners either as parts of the plant itself or as disease organisms rather than insects. Adult female scales are small and immobile, with no visible legs. They secrete a waxy coat that varies significantly in shape and color depending on the species. Adult males tend to be very small and have wings, which allow them to fly so they can locate females.

Scales feed on plants by piercing the leaf, stem, or branch with their mouthparts and sucking sap. Their feeding can weaken or kill branches. Heavily-infested gardenias are often stunted with small flowers and leaves. Leaves may yellow and drop early. Like aphids, soft scales excrete honeydew. Armored scales do not excrete honeydew. The growth of the sooty mold fungus on the honeydew results in leaves that are covered in dark fungal growth. See the Sooty Mold section in HGIC 2058, Gardenia Diseases & Other Problems, for detailed information.

Adult scales are relatively well protected from traditional contact insecticides by their waxy covering. Their immature forms, called crawlers, are susceptible, however.

Control: A combination of various natural enemies, including ladybird beetles (ladybugs) and parasitic wasps, usually keep scale insects under control. With light infestations, scale can be scraped off or infested branches can be removed and destroyed.

Horticultural oil is an excellent, proven product for scale control. It alone will control all stages of armored scales on gardenias and other shrubs. Horticultural oil is safe to use and is an especially good choice for sensitive areas, such as where people are present soon after treatment. Because of the short residual, oil sprays help to conserve beneficial insect species. Horticultural oil sprays kill by suffocation. Spray in early spring to kill any overwintering adults, crawlers, or eggs. Apply these spray applications again when new leaves start to expand in the spring. At least two more spring applications are needed at five- to six-week intervals. Spray the plants thoroughly, so that the oil sprays drip or “run-off” from the upper and undersides of leaves, branches, and trunk. It is best to spray horticultural oil when the temperatures are above 45 and below 90-degrees, and to spray during the early evening to slow the drying of the oil spray application. Spray when no rainfall is in the forecast for the next 24 hours.

Follow label directions for mixing rates with water. Typically, a 1 or 2% mixture of horticultural oil is applied. On mature foliage, apply a 2% mixture spray (5 tablespoons of oil per gallon of water). During the spring, as new tender growth appears, apply 1% mixture spray (2½ tablespoons per gallon of water).

Insecticidal soap sprays work well to control soft scale adults and crawlers. Like with a horticultural oil spray, spray soaps when temperatures are below 90 °F, and spray in the evening to reduce the drying time of the spray. Spray the plants thoroughly, so that the oil sprays drip or “run-off” from the upper and undersides of leaves, branches, and trunk. Follow label directions for mixing and use.

In terms of traditional contact insecticides, only the crawler stage is susceptible. Recommended insecticides for use against crawlers include the following: acephate, permethrin, cyhalothrin, cyfluthrin, bifenthrin, and esfenvalerate. Apply these materials only when crawlers are present and repeat after 10 days.

Soil-applied insecticides can give season-long control of scale insects. Dinotefuran can control both soft and armored scales. This treatment is applied as a soil drench or as granules, which are then watered into the soil. See Table 1 for products containing dinotefuran. A spring application is the most effective. As with all pesticides, read and follow all label instructions and precautions.

Aphids: These small (about 1/8 inch long), soft-bodied, pear-shaped insects are sometimes referred to as plant lice. They vary in color according to species and can be shades of green, yellow, pink, or black. Both the green peach aphid (Myzus persicae) and the melon (or cotton) aphid (Aphis gossypii) feed on gardenias. They are usually found in clusters on new growth of buds, leaves, and stems.

Aphids feed on plant sap with their piercing-sucking mouthparts. A low population of aphids does little damage to a gardenia; however, aphids reproduce very rapidly and can quickly reach numbers that cause damage. Their feeding results in distorted or curled and stunted growth. Heavy infestations can reduce the number and quality of blooms. As they feed, aphids excrete honeydew, a sugary substance that often attracts ants. In addition, honeydew supports the growth of unsightly, dark-colored sooty mold fungi on the leaves. See the Sooty Mold section in HGIC 2058, Gardenia Diseases & Other Problems for details.

Control: Aphids have several natural enemies, including parasitic wasps, ladybird beetles (ladybugs) and larvae, and green lacewing adults and larvae. Their natural enemies tend to keep aphid populations under control except in cool weather. Ants are sometimes present with aphid infestations and will protect them from their natural enemies. If ants are present, they should be controlled.

Aphids can be hosed off with a strong stream of water directed above and below the leaves. Spray frequently with water, repeating as needed, focusing on new growth. Gardenias can also be sprayed with insecticidal soap or horticultural oil to control aphids. Insecticidal soap or horticultural oil must be sprayed onto the aphids to be effective. Repeat spray three times at 5 to 7-day intervals. Foliar injury from soaps and oils may occur on plants under drought stress. Water the plants well the day before spraying. Only apply horticultural oils or insecticidal soaps if temperatures are below 90 °F, and apply very late in the day to prevent foliar injury.

While higher toxicity insecticides are available, it is important to note that aphids are very difficult to control because they multiply so rapidly. Leaving even one aphid alive can quickly result in a population explosion. In addition, these insecticides kill the natural enemies of aphids.

If stronger insecticides are deemed necessary, the following are available in homeowner-size packaging. Sprays containing acephate, bifenthrin, cyfluthrin, permethrin, cyhalothrin, esfenvalerate, malathion, neem oil, or pyrethrin will control aphids. Soil drenches or granular applications of imidacloprid or dinotefuran will control aphids and last longer within the plant to prevent future infestations. See Table 1 for products containing these insecticides.

Insecticide For Gardenias

The gardenia plant is a beautiful and fragrant shrub that can be grown in a garden or in large containers. Gardenias are native to China and Japan, but were introduced to the United States in the 19th century. They can be grown in either full sun or light shade, and prefer moist soil. If you’re looking to grow gardenias in your own backyard, it’s important to know how they differ from other plants in order to properly care for them.

The best way to combat pests on your gardenia is with an insecticidal soap spray. This product kills bugs without harming your plants or the environment around them! The best part about this type of pesticide is that it’s made from natural ingredients like vegetable oil and potassium salts – so no harsh chemicals are involved!

List Of Insecticide For Gardenias