The common evening primrose is native to North America. Slugs, mice and birds may also eat the flowers or foliage. Both the longtailed and obscure mealybugs are problems on primrose, though distinguishing between them at a glance can be difficult. Why Does an Orange Jasmine Lose Its Leaves? If a plant collapses suddenly, it may indicate a weevil infestation. © Copyright 2020 Hearst Communications, Inc. Primrose are among the first flowers to bloom in spring, and they grace many gardens around the country. Primroses do best in your garden if you plant them in a cool section that offers the plants lots of bright light. The perky flower of the primrose (Primula spp.) It is essential to preventing primula disease problems to select a site with excellent drainage, since the primula roots can be damaged in winter when soil is wet or heavy. You’ll need to throw out infected plants and apply a fungicide to healthy plants to protect them. Insecticidal soap and horticultural oils are very effective against aphids, but be sure to test a small area of the primrose before application in case your plant is sensitive to these chemicals. Young weevils are grubs, the color of cream with brown heads. Waterworth received a Bachelor of Arts in American history from Columbia College. Treating these insects is difficult, since they are protected by plant tissues -- often the best control is to remove affected foliage and burn it. If all else fails, chemical treatments are also available at your garden store. They feed on the sap of primrose and form white cottony masses on affected plants. It seems that the whole of the insect kingdom savors the flavor of primrose. If your plants get root rot, damping off or crown rot, they wilt and die. Don’t give the plants too much water in cold winter conditions. The adult weevil is brown and looks like a beetle. Two-spotted spider mites are very small arachnids that are difficult to see without magnification. If the fungus appears, spray with a fungicide. The larval stage of the serpentine leafminer tunnels its way through the leaves of primrose as it feeds. Sign up for our newsletter. Adults appear in fall and can eat notches out of the edges of leaves. Even with the best of cultural care, some pests of primula can attack your plants. If your plant growth is stunted and they seem to be branching too much and show yellow, strap-shaped leaves, they may have yellow asters, another of the primula disease problems. Spray affected plants with horticultural oils -- being sure to coat all sides of the leaves -- and apply reflective mulch around primrose to prevent future infestations. Sign up to get all the latest gardening tips! Evening primrose (Oenothera spp.) From there, her meandering career path led to a 9 1/2 year stint in the real estate industry. Primroses do best in your garden if you plant them in a cool section that offers the plants lots of bright light. The shiny black cowpea aphid also injects toxins into plant materials that can kill tissues or whole plants. Many primula disease problems can be avoided by good cultural habits. Find more gardening information on Gardening Know How: Keep up to date with all that's happening in and around the garden. Slugs and snails are other pests drawn to evening primrose. It is included in an evolving list of plants carefully … These tips about how to grow primroses help keep down problems with primroses. Traps should also be placed near affected areas. RHS Plants for Pollinators plants. When large areas of leaves have been eaten from the margin inward, suspect caterpillars like the black cutworm or the beet armyworm. You can often avoid this issue by ensuring that the air circulates around the plants. If infestation is extensive, feed and water the plant to support it while targeting adults with sprays of azadirachtin or pyrethrin. University of California Integrated Pest Management Program: Primrose, University of California Integrated Pest Management Program: Aphids Management Guidelines, University of California Integrated Pest Management Program: Foliage-Feeding Caterpillars, University of California Integrated Pest Management Program: Leafminers, University of California Integrated Pest Management Program: Mealybugs, University of California Integrated Pest Management Program: Spider Mites, University of California Integrated Pest Management Program: Thrips, University of California Integrated Pest Management Program: Weevils, University of California Integrated Pest Management Program: Whiteflies, Insects and Yellowing Leaves on Tomato Plants. The narrow-bodied, white to yellow winged greenhouse whitefly is sometimes a problem of primrose when their natural enemies have been destroyed by pesticides or environmental pressures. With more than 400 members in this large genus, the variety of colors and textures is almost endless. Cowpea aphid; Green peach aphid; Foliage-feeding caterpillars Beet armyworm; Black cutworm; Leafminers Serpentine leafminer; Mealybugs Longtailed mealybug The mines are extremely visible, marring the foliage of affected plants. Since the plant can spread quite quickly and colonize many habitats, it was found in w… This plant will provide nectar and pollen for bees and the many other types of pollinating insects. They are soil dwellers and eat primula roots. An increasing market for evening primrose oil requires increasing supplies of seed which may result from improved cultivars and husbandry techniques as well as spread of the crop to new production areas. Green to pink-green peach aphids are less damaging, but can exhaust plants if their numbers are high. Many primula disease problems can be avoided by good cultural habits. The vine weevil is the most destructive of the pests of primula. Kunth's evening primrose (Oenothera kunthiana) is about 18 inches tall, but its stems tend to recline and trail on the ground. Proper planting and culture can prevent many primula plant problems, but it is a good idea to become familiar with some of the diseases and pests of primula. Handpicking weevils is often effective to control populations when coupled with nutritional support for damaged plants. They also leave behind a slimy substance which displays where they crawl on the plant. Your first, and most important, step to avoiding primula plant problems is planting them correctly. They also extend the flowering season for these plants. Kristi Waterworth started her writing career in 1995 as a journalist for a local newspaper. One of the most … Plant extracts that have been formulated for mite problems, such as mint oil, can greatly decrease numbers without damaging predator populations. Inspect and empty your traps every day. Sometimes you can also stop adults from laying eggs on the plants by placing gravel around them. They come out at dusk and will chew holes in your herbs. Both caterpillars can be controlled with applications of Bacillus thuringiensis or spinosad. Insecticides are rarely effective on whiteflies. Other pests of primula include root aphids – which can often be controlled by keeping the garden bed free of weeds. Stippling or bronzing of leaves results from spider mite activities. Oenothera biennis (common evening-primrose, evening star, sundrop, weedy evening primrose, German rampion, hog weed, King's cure-all, or fever-plant) is a species of Oenothera native to eastern and central North America, from Newfoundland west to Alberta, southeast to Florida, and southwest to Texas, and widely naturalized elsewhere in temperate and subtropical regions. Black cutworms are brown to grey night-feeding caterpillars that hide in the soil near their chosen plants. Spray mealybugs with a garden hose to dislodge them, or treat the plant with insecticidal soap. While these mines are largely cosmetic problems, leafminer larvae can occasionally introduce disease. Pests and disorders of Primula spp. Around the middle of the 17th century, the plant was introduced by sea to Europe and quickly attracted a lot of attention in many gardens as an ornamental plant. These small, soft-bodied insects feed by inserting special mouthparts into leaf and stem tissues. Since 2010, she's written on a wide range of personal finance topics. You can hand pick these pests, or you can sprinkle coffee grounds or diatomaceous earth on the ground around the base of the plant. These small, soft-bodied insects feed by inserting special mouthparts into leaf and stem tissues. These bright flowering plants are also called Primula, which is their genus name. The narrow-bodied, black greenhouse thrip feeds on primrose plants, leaving a wake of bleached leaves with black residue on their undersides. It's no wonder, then, that primrose is grown so widely by gardeners in U.S. Department of Agriculture hardiness zones 4 through 8 despite pest problems. Primrose suffers from a wide range of pests, from sap-feeding insects to leafminers and caterpillars. You’ll have to throw away primroses infected by this disease. Aphids. Trap adult pests by leaving out rolls of corrugated paper or flowerpots stuffed with fresh grass. Both black vine weevils and Fuller rose beetles feed on primrose, given the chance. These pests are distinguishable by the fine webs they spin in areas where feeding is taking place.