They prefer rose growth that is young, with soft thorns, but may chew or nibble flowers and older canes. Consuming as much as 8 pounds of plant material per animal daily, a small herd of deer can quickly eat roses to the ground if left unchecked. During their breeding season, males may shred your bushes with their antlers in an attempt to leave a scent marker for receptive females.
Many homeowners try to repel deer initially, hoping to scare them away. Hungry deer won't be gone for long, but if your neighborhood herd is just looking for an easy meal, you may find some success with repellants if you also remove any deer-friendly cover within 60 feet of your roses. Homeowners often spread contact repellants containing hot sauce or rotten eggs on troubled plants to stop deer from chewing.
Area repellants such as predator urine, sold at garden stores, or human hair may be spread along boundaries to scare deer before they reach troubled plants. Grubs hatch from the eggs and feed on grass roots. As the weather cools, the grubs move more deeply into the soil to overwinter survive the winter.
In the spring, the grubs migrate back up to the root zone and continue to feed. They pupate change to adult form in late April and May. Japanese beetles have chewing mouthparts and feed on flowers, buds, and leaves of roses as well as numerous other plant species. Partial or entire flowers and buds may be eaten. Affected buds may fail to open. Rose leaves are typically skeletonized only leaf veins remain by the feeding.
Leaves with tender veins may be eaten completely. Control: Various non-chemical control options are available for Japanese beetles. They can be handpicked and destroyed by dropping them into soapy water.
When only a few plants are involved, fine netting, such as tulle fabric, or spunbound polyester fabric, such as Reemay, can be placed over the bush or individual blossoms to exclude the beetles.
Japanese beetle traps are available commercially but should be used with caution. They can effectively reduce adult populations, but they should be kept at least 50 feet from the plant s being protected. The traps have the potential to create more of a problem by attracting numerous beetles into the landscape Additionally, traps must be emptied frequently as beetles are repelled by the smell of ammonia, which is released by dead, rotting beetles. The number of adults may also be reduced by using the product Milky Spore against the grubs in the lawn.
This product contains a disease-causing bacterium Paenibacillus popilliae that specifically infects the grubs of Japanese beetles. It is applied to the entire lawn, and once established, can be effective for 20 to 30 years. However, as the adults are strong fliers, they can fly in from nearby lawns and pastures.
It is important to keep in mind that rose blossoms openly quickly and are very attractive to Japanese beetles. These circumstances make it challenging to keep the blooms adequately covered with insecticide to protect them. Insecticides labeled for homeowner use include sprays containing bifenthrin, cyfluthrin, lambda cyhalothrin, neem oil, permethrin, or pyrethrin to control beetles. Soil drenches or granular applications of imidacloprid or dinotefuran will control Japanese and other beetles and last longer within the plant to prevent future infestations.
See Table 1 for specific products. Mites are not insects but are more closely related to spiders with eight legs as adults instead of six. One way to detect them is to hold a piece of white paper under a branch and then tap the branch sharply. Wipe your hand over the paper. If mites are present, red streaks will be seen.
Two-spotted spider mites Tetranychus urticae and southern red mites Oligonychus ilicis are pests on roses in South Carolina. Two-spotted spider mites are more of a problem during hot, dry weather, and susceptibility increases when a rose is drought-stressed. Southern red mites are more of a problem during cool weather in spring and fall, and their populations drop during summer.
Spider mite Tetranychus urticae webbing and plant injury. Mites have piercing-sucking mouthparts. They suck plant sap, typically feeding on the lower surface of a leaf. Early damage is seen as yellow or white speckling on the upper surface of leaves. Fine webbing may be seen on the undersides of leaves. With severe infestations, leaves may develop a grayish-green or bronze color, and webbing may cover both sides of leaves and branches. Severely infested leaves may drop prematurely.
In addition, the webbing can collect dust, making the plant look dirty. Control: Beneficial insects, such as lacewings, lady beetles, and predatory mites, prey on spider mites. Predatory mites are about the same size as spider mites but can be distinguished from spider mites by their long legs and the speed with which they move.
Several species of predator mites are available commercially for use as biological control agents. A strong spray of water is a non-chemical control option that removes eggs, larvae six-legged immature stage , nymphs eight-legged immature mites , and adult mites. Be sure to spray lower surfaces of leaves and repeat as needed. This method is most effective with light infestations, as seen with early detection. An important advantage of this control method is that populations of natural enemies are not harmed.
Insecticidal soaps and horticultural oils are effective control options for spider mites, and they are essentially nontoxic to humans, wildlife, and pets, and only minimally toxic to beneficial predators. Good coverage is critical to ensure contact with the pest when using these products, and reapplication may be needed as determined by follow-up monitoring for the pest.
Foliar injury from soaps and oils may occur on plants under drought stress. Water the plants well before spraying. Sulfur sprays can also control spider mites. When growing roses, the use of broad-spectrum insecticides should be avoided as much as possible, as these products can kill off natural enemies that help keep spider mite populations in check. See Table 1 for examples of brands and products.
Various thrips species feed on roses. Two of the most common are flower thrips Frankliniella tritici and western flower thrips F. Thrips Frankliniella sp.
Clemson University. Adult female thrips of both species are tiny, yellowish-brown insects with fringed or feathery wings. However, blowing lightly into the blooms and leaves causes thrips to move around, making them easier to see. Both immature and adult thrips feed by scraping surface cells to suck plant sap. They feed on both leaves and flower petals, with the majority of their damage to roses occurring from early to midsummer. Their feeding may result in distorted buds that open only partially or abort prematurely.
Feeding on petals may result in petals streaked with silvery-white or brown as well as petals with browning edges. White and light-colored rose blossoms appear to be particularly attractive to thrips. Young leaves become distorted and flecked with yellow following extensive thrips feeding.
Control: Control of thrips is difficult. Infested rose blossoms should be removed and destroyed. Grass and weeds in the area should be kept mowed or removed when possible.
Insecticides are available, but the timing of sprays is very important. They must be applied before thrips enter unopened buds. In addition, because rose blooms expand rapidly, it is challenging to keep them adequately covered with insecticide. A heavy infestation of rose slugs can strip your plant bare of the leaves.
These are nighttime feeders that are most active in early spring to late summer. The best control method is to knock them off the plant either by hand or hosing the leaves early each morning. If you do need to use an insecticide, horticultural oil and insecticidal soaps work as contact insecticides killing on contact.
Not by ingestion. The fuller rose beetle can do severe damage to roses. They eat the leaves and the flowers. Eggs hatch in the soil and the larvae start to feed on the plants roots for up to 8-months, eventually emerging as fuller rose beetles around spring the following year.
Adult rose beetles are brown and wingless. Not in the soil. The damage they cause is distinctive. On the leaves they are eating, the only part that will remain untouched will be the thick large vein running down the center of the leaf their feeding on. The severity of the damage this pest causes will require remedial action to revive a dying rose. It might be heavily damaged this year, but it can survive heavy defoliation. These can eat multiple leaves, and the flowers. To stop these eating your rose leaves, remove them by hand or hose them off with a jet spray of water.
Take advantage of their inability to take flight by skirt pruning your rose bush.
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