The most common cause of holes in green bean leaves is damage from insects. Bean Leaf Beetles are a common culprit, but snails and caterpillars can also leave holes in your bean leaves.
Beans are one of the tastiest harvests you can grow in your garden, but they’re not immune to pests and other issues. If you start noticing holes or rips in your green bean leaves, it’s probably time to take action so that your harvest isn’t ruined by these common pests.
Bean Leaf Beetles
Bean leaf beetle is a small insect that feeds on the leaves of beans, peas, and other legumes. The adult beetle is about 1/4 inch long and has an orange body with black spots on its wing covers.
The adult beetles lay eggs that hatch into larvae in about two weeks. These larvae then burrow into the soil where they feed on plant roots until they mature into adults and emerge from the ground as adults in about 4 to 6 weeks.
They can be difficult to control because they fly away when they’re disturbed so applying pesticides is the only way to eliminate them from your garden. They also tend to be found on one side of the plant rather than randomly throughout it. The damage caused by bean leaf beetles can have a significant impact on your garden’s yield, so it is important to control this pest.
They do more damage when there is already stress on the plant from drought or other environmental factors. This makes it harder for the plant to recover from damage done by bean leaf beetles.
Slugs and Snails
Slugs and snails are common garden pests that can do serious damage to your plants. They eat leaves, stems, and roots, which can stunt growth and kill the plant if left unchecked.
Look for dull, light green or yellowish spots on the leaves. The undersides of affected leaves will be covered with slime trails.
To control slugs and snails, you’ll need to keep the area around your plants free of debris for them to hide in. If you see one in your garden, use a flashlight to find it at night when they come out to feed. Once you’ve spotted it, either kill them right away or sprinkle some salt around the area where you found it so that it can’t get back there again.
Cutworms are the larvae of moths. They can be found in the soil, feeding on the stems of plants. Cutworms feed at night, so you may not see them at first.
Cutworms are white or brown and have a cylindrical body shape. They are about 1 to 2 inches long, depending on their age and whether they have molted recently.
Cutworms can be identified by their lack of legs or prolegs the part of their body that attaches them to plants and by the way they curl up into a C-shape when disturbed or when you try to pick them up!
Cutworm damage usually appears as holes in leaves and stems where the caterpillar has chewed through them. Most often this happens at night or early in the morning when it’s still dark out, so you might not notice it until later in the day.
Grasshoppers are small insects that are green or brown in color and have a long antennae that they use to sense their environment. They are most active during the day and will tend to hide under leaves or in the shade during the night, when temperatures drop.
Grasshoppers are common pests that love to eat the leaves and stems of many different types of plants, including cabbage, lettuce, and many other veggies and herbs you may have growing in your garden.
The best way to get rid of these pests is by using pesticides such as pyrethrum spray, if you don’t want to use chemicals then try using insecticidal soap instead!
Spider mites are one of the most common pests in greenhouses and gardens. They are very small and difficult to see, but they can cause significant damage to plants. If you notice that your bean leaves have holes in them, chances are they have been attacked by spider mites.
Spider mites are tiny, spider-like creatures that live on plants. They have eight legs and they move around quickly, usually in groups. Spider mites are not insects, but arachnids.
Spider mites suck the juices out of plant leaves and cause yellow spots to appear on the leaves. As they feed, they leave behind silken webs that look like fine white powder or specks on the leaf surface. These webs may be visible with a hand lens or magnifying glass. Fortunately, spider mites can be easily treated with neem oil spray or horticultural oil.
Leaf miners are common on all sorts of plants, but you may not know it because they are so small. Leaf miner larvae are often so small that they can be easily overlooked by gardeners who aren’t looking for them. They get their name from the fact that they mine their way through plant tissue, leaving behind telltale trails of black excrement as they move around inside leaves or stems.
The damage caused by leaf miners is limited to discoloration and various degrees of disfiguration due to the paths left behind in the leaf’s interior by larval feeding activity. Leaf miners rarely kill plants outright, but severe infestations can cause severe damage over time as large areas of leaves are consumed by these tiny pests!
Beet armyworm is a caterpillar (the larval stage) of a moth called Spodoptera exigua. The caterpillar has dark stripes on its body and a yellowish-green scent gland on top of its head. The caterpillar goes through five stages before becoming an adult moth. The adult moths have dark brown or black wings with white spots along the margins and white hairs near their wing tips. Beet armyworm can be found in the southwestern United States and Mexico, but it can be found throughout most of North America.
Mexican Bean Beetle
The Mexican bean beetle is a common pest of beans and other legumes. The adult beetles are small, oval, light brown or yellow in color, and have distinct spots on the wing covers and the larvae are pale yellow.
Mexican bean beetle adults feed on leaf tissue between the veins, leaving round holes in the foliage. Feeding damage by the larvae results in skeletonized leaves that appear as if they were eaten by caterpillars. The presence of these beetles can be detected by looking for small holes in the leaves of beans or other legumes.
In spring, adults emerge and begin feeding on seedling plants or older plants that have been damaged by frost or other environmental stresses.
In late spring through early fall, adults lay eggs on leaves and stems of host plants, young larvae hatch from these eggs and feed until they reach full size. Larvae overwinter inside plant stems near soil level where they pupate into adults late in summer or early fall.
White mold is a common problem for green beans, and it’s caused by a fungus called Sclerotinia sclerotiorum. This fungus grows on the leaves of plants, especially in warm and humid conditions.
White mold can look like spots or fuzzy growth on your beans’ leaves. The spots can be white and powdery, or they might have a yellowish tinge to them.
If you notice these signs of white mold on your green bean plants prune off any affected leaves as soon as possible so that the fungus doesn’t spread throughout your garden.
Bean rust is a fungal disease that affects many plants, including beans and other legumes. The fungus that causes bean rust, Uromyces appendiculatus, can infect the leaves, stems, and pods of affected plants.
The symptoms of bean rust are easy to spot and include yellowing of leaves, brown spots on leaves, and small black dots on the undersides of leaves. These spots will grow until they turn black and eventually fall off. The plant may also stop producing beans or produce fewer than usual.
This disease is spread by wind-blown spores that land on healthy plants. It can also be spread by infected seedlings if they were planted near an infected plant. If you have bean rust on your plants, you should remove them immediately so they don’t infect other plants in your garden!
Bean common mosaic virus is a disease that causes lesions on leaves, stems, and pods. The virus is spread through contact with infected plants or contaminated tools or hands. It can also be transmitted via insects like aphids or leafhoppers that feed on plants with the virus in them.
The first symptoms to appear are small, yellow spots on the upper surface of leaves that look like water droplets. As the disease progresses, these spots become larger and turn brown or tan. When they reach a certain size, they fall off the leaf in large patches.
It can be prevented by following good garden hygiene practices, washing your hands after working with plants that could have been infected, maintaining healthy soil by adding compost annually, avoiding overhead watering which can spread the disease, and planting resistant varieties of your favorite bean-type crops if possible.
When will the holes in my green bean leaves go away?
The holes in your green bean leaves will disappear when the insects that made them are gone. You can help this along by spraying your plants with insecticide, or by hand picking the insects off the plants. If you do not want to use chemicals, you can try organic methods for getting rid of insects.
The holes will also go away when your plants mature and become strong enough to resist pests better than they did when they were young and vulnerable. Wait until about 2 weeks after all pest activities have stoped and new growth has started.
Hopefully this blog has given you some insight into what causes holes in green bean leaves, as well as how to prevent them.
If you’d like to learn more about gardening, or if you have any questions about the topic of this blog, feel free to reach out!