Hollyhocks (Alcea rosea) are beautiful, old-fashioned flowers that add height and vibrant color to any garden. However, these plants are prone to infestations of bugs that can quickly damage the foliage and flowers. Learning how to properly identify and treat these pests is key to keeping your hollyhocks looking their best.
Common Hollyhock Bugs
There are a few main insects that tend to attack hollyhocks
-
Hollyhock Weevils – The most prevalent pest is the hollyhock weevil (Rhopalapion longirostre). These are small grayish-black beetles that eat the leaves and lay eggs inside the flowers. The larvae then feed on the seeds.
-
Japanese Beetles – These metallic green and copper beetles devour the foliage and flowers. They are generalists and also attack many other plants.
-
Aphids – Look for clusters of small, soft-bodied insects on the leaves and stems They extract plant sap, causing distortion and yellowing.
-
Leafhoppers – Tiny green or brown bugs that jump when disturbed. They suck nutrients from the leaves, causing stippling damage.
-
Slugs and Snails – These leave large holes in foliage and chew on petals overnight. Look for their slime trails.
Physical Control Methods
For mild infestations, manually removing the bugs can help reduce their numbers:
-
Hand pick insects off plants and drop them into a bucket of soapy water. Do this in the evening when some bugs are more active.
-
Use a strong spray of water to knock off and disturb them.
-
Attract natural predators like birds, ladybugs, lacewings, and praying mantises to your garden. They will help eat many pests.
-
Place slug and snail traps like beer traps around plants overnight to catch them.
-
Use sticky traps near plants to monitor and reduce pests like whiteflies, leafhoppers, and fungus gnats.
-
Remove and destroy severely damaged foliage and flowers to eliminate eggs and larvae.
Organic Pesticide Sprays
For heavy infestations, spraying eco-friendly pesticides can help:
-
Insecticidal soaps – Effective against soft-bodied insects like aphids. Spray leaves until soaked.
-
Neem oil – Kills many chewing and sucking insects. Mix with a bit of dish soap and spray all plant parts.
-
Pyrethrin – Derived from chrysanthemums, this targets many common garden pests. Avoid spraying open flowers to not harm pollinators.
-
Diatomaceous earth – This powder dries out and kills soft-bodied insects. Dust leaves, avoiding open blooms.
-
Bacillus thuringiensis (Bt) – This targets caterpillars like loopers and hornworms. Spray leaves and stems fully.
-
Horticultural oils – These smother soft-bodied insects on contact. Do not spray when temperatures are above 90°F.
-
Insecticidal fungi – Beauveria bassiana fungal spores infect and kill many insects naturally. Spray in the evenings.
Make sure to cover the undersides of leaves and upper and lower stem surfaces where many pests hide and feed. Always follow label application directions when using any pesticide. Reapply as needed, usually every 7-14 days.
Preventing Future Infestations
There are some cultural practices that can help reduce bugs on hollyhocks:
-
Remove and destroy damaged plant material and debris around plants to eliminate places where bugs can overwinter.
-
Rotate hollyhocks to different garden areas each year to disrupt pest cycles.
-
Clean up dropped and diseased fruits and foliage promptly to avoid spread.
-
Use row covers over plants in early spring to exclude early season pests.
-
Water at the base of plants in the morning to avoid wet foliage at night when it promotes fungal and bacterial diseases.
-
Fertilize plants according to soil test recommendations to avoid excessive, succulent growth that attracts pests.
-
Grow resistant hollyhock varieties like ‘Powderpuffs,’ ‘Chaters Double,’ and ‘Queeny Purple’ that deter certain diseases.
With diligent monitoring, quick treatment, and prevention, you can enjoy beautiful, pest-free hollyhocks all season long. Be sure to take an integrated approach by combining several cultural, physical, and organic control methods for the best results in combatting bugs on these flowering beauties.
What are Hollyhock Weevils?
Hollyhock weevils (Apion longirostre) are gray snout beetles with orange legs, measuring 1/8 to 1/4 inch (3-6 mm. ) long, including their pronounced proboscis, which is significantly longer in females than males. Hollyhock weevil adults spend the winter in the soil of hollyhock beds that are already infested. In the spring, they come out to feed and lay their eggs. The female chews a small hole in a flower bud and then inserts a single egg. This process is done many times.
The hollyhock weevil egg doesn’t get in the way of flower growth; instead, it gets wrapped up in the hollyhock seed pod as it grows. Here, the larvae eat and change into pupae. From late summer to early fall, they come out as adults and drop to the ground. Hollyhock weevils produce just one generation a year in most locations.
Weevil pests on hollyhocks cause only minor visual damage, chewing small holes in hollyhock leaves and flowers. However, they can cause serious damage to the overall lifespan of hollyhock stands. Larval hollyhock weevils develop within the hollyhock seed pods, using embryonic seeds for food. When the seed pods are mature, they are often empty, preventing hollyhocks from self-seeding. Hollyhocks are short-lived perennials that may not bloom for up to two years. Hollyhock weevil larvae can seriously mess up the life cycle of your hollyhock bed.
Hollyhock weevils like to come out at night, so keep an eye out for adults and feeding damage in the spring. Before you decide what to do, you should carefully look at your plants with a flashlight after dark to see how bad the pest problem is. Hollyhock weevils can often be picked off of hollyhock buds and leaves by hand and thrown into a bucket of soapy water to drown.
There are safer ways to kill insects when hollyhock weevils are stuck to leaves or when there are so many of them feeding on your plants that you can’t pick them all by hand. Spray insecticidal soap directly on these pests; it will kill them on contact. Hollyhock weevils may not be able to lay eggs if you catch them early in the season. You can do this by checking every night and getting rid of any pests you find until you don’t find any more.
If the hollyhock weevil couldn’t get to your seeds, you should destroy the seed pods as soon as you see them to get rid of the eggs, larvae, and pupae. If this happens again, it will hurt the next generation of hollyhocks, but most of the seeds will probably have already been eaten. In the long run, getting rid of last season’s seeds could save your whole stand and make the area good for planting hollyhocks again.
MAKING FUNGICIDE FOR HOLLYHOCK RUST/ SPRAYING IT TO THE PLANTS
FAQ
What can I spray on hollyhocks?
How do you make bug spray for hollyhocks?
What is making holes in my hollyhock leaves?
What is eating the leaves off my hollyhocks?
How do you get rid of aphids on hollyhocks?
You may also notice sticky residue on the leaves, which is known as honeydew. Treatment: There are several methods to control aphids on hollyhocks. One option is to spray a strong stream of water onto the infested plants to dislodge the aphids. Alternatively, you can use insecticidal soap or neem oil spray to kill the pests.
Do hollyhocks need pest control?
Hollyhocks (Alcea rosea) lend an old-fashioned charm to the back of the garden border, or serve as a seasonal living fence, creating a little extra privacy through the spring and summer. Even though these plants are often extremely tough, a little hollyhock pest control will keep your bed filled with blooms for years to come.
Are Hollyhock weevils a pest?
Hollyhock weevils are common pests and can turn your plant leaves into an ugly mess. Learn how to identify and eliminate these pests now.
How do you get rid of hollyhocks?
One option is to handpick them off your hollyhocks and relocate them away from your plants. Creating barriers such as copper tape or diatomaceous earth around your plants can also deter these pests. Additionally, you can use organic slug and snail baits that are safe for pets and wildlife.
How do I get rid of Hollyhock weevils?
Safer insecticidal options are available when hollyhock weevils cling tightly to leaves or there are so many feeding on your plants that hand-picking becomes an insurmountable task. Spray insecticidal soap directly on these pests; it will kill them on contact.
Why do hollyhocks have holes in their leaves?
If irregular holes show up in new hollyhock leaves in the spring, you may suspect the hollyhock weevil (Apion longirostre). The insect is host-specific and will not spread to other plants. Find it in U.S. Department of Agriculture plant hardiness zones 2 through 10 where hollyhocks thrive.