Beans are one of the most popular vegetables for gardeners. They are incredibly easy to plant, maintain, and harvest, which explains why they are so popular among all, beginners and experts alike. But these plants aren’t without their share of problems.
The top common problems growing beans include the browning, yellowing or whitening of leaves, holes in the leaves, the plant not flowering, curling leaves, etc. These problems may lie on anything from insects, microbes, parasites, soil quality, temperature, spacing, etc.
Given the popularity of beans as a garden vegetable, most of the problems people run across have been dealt with beforehand by veteran gardeners. So there’s plenty of solutions you could try to deal with your particular problem. In this article, we will be looking at 7 of the top common problems growing beans and how you can fix each of them.
Bean Plant Leaves Turning Yellow/Brown
Problem: The leaves of your bean plant are turning yellow/brown.
There are a number of reasons why the leaves of a bean plant will turn brown. One of the most common reasons is a fungus infection. Beans are prone to a fungal disease known as Anthracnose. This disease is responsible for leaving brown marks known as rust on the leaves and other parts of the bean plant.
To fix this problem, apply fungicide when the rust begins to appear. You should also regularly rotate your crops.
Insects & Worms
Another common reason why the leaves of a bean plant turn brown is if they are being attacked by either spider mites or nematodes. Spider mites will consume the juice from the leaves till they turn yellow and then brown. Nematodes, on the other hand, infect the black from the bottom, first attacking the root.
To fix the problem with spider mites, you should consider keeping ladybugs around your plant. They will eat the spider mites. For the nematodes, you can try solarization, or else you will have to leave the mud fallow for some time.
Another recurring culprit behind the yellowing/browning of leaves in bean plants is bacteria. You will first notice water spotting or drying of the leaf edges. This will eventually spread inside until it has consumed the entire leaf. Halo blight is the most common bacterial infection in beans. You will notice yellow spots that gradually grow and consume the whole leaf.
To fix this problem, you will have to consider changing the soil. Most bacteria that affect bean plants live in the soil. You can also get blight-resistant seeds.
Mosaic virus infection is one of the most common infections in beans. This virus affects various types of vegetables, and the symptoms include multi-coloring of the leaves that eventually lead to their yellowing or browning.
Unfortunately, there is no concrete fix for a mosaic viral infection. So the best you can do is replace the soil, leave it fallow for some time and then take the proper preventive measures.
Often, this virus gets transmitted from insects and parasites. So make sure you’re using pesticides to take care of them. You can also find mosaic virus-resistant bean seeds in the market. Using them instead of regular seeds could also help. You can also try using reflective aluminum mulches.
Lack of Balance of Nutrients
Another factor you might have overlooked is the lack of proper balance of nutrients for your plant. Like most plants, beans derive certain minerals like nitrogen, phosphorus, manganese, potassium, and magnesium from the soil. If the soil has too much or too little of any of these, it could lead to problems like browning of the plant.
To fix this problem, get the soil tested and make sure it has the right amount of minerals. Manganese is a common culprit. Consider getting the soil replaced.
Bean Plant Leaves Curling
Problem: The leaves of your bean plant are curling.
There are two major categories of insects that are usually responsible for the curling of leaves in bean plants. The first are the aphids, which are tiny sap-sucking insects. They are usually found on the underside of leaves and are green, yellow, black, or brown in color.
To protect your plant against aphids, the use of predatory insects such as ladybugs is encouraged. Although pesticides can deal with aphids as well, they should only be used as a last resort as they can discourage other useful insects too.
Another insect possibly responsible for the curling of leaves is whitefly. These are little insects with white wings, and unlike the aphids, they themselves aren’t directly responsible for the curling. They facilitate this by transferring a certain type of virus known as the Cucurbit Leaf Crumple Virus.
To protect your plant against whiteflies, you can try using aluminum mulches on your plants. You should keep new batches of beans away from old infected batches. As a last resort, you can also use certain pesticides.
We have already discussed the Mosaic virus infection in the previous section. This virus, besides turning the leaves yellow or brown, can also curl the leaves of the plant.
But the most common culprit of curling in bean plants is the Cucurbit Leaf Crumple Virus. Like Mosaic virus, this virus affects different vegetables and results in the leaves being curled. If you do end up getting beans from infected plants, they usually look defected.
Both of these viruses get transmitted by insects and pests. So preparing for this beforehand is your best bet. You can do this by using reflective aluminum mulches. These work great at deflecting insects and pests from your plants. Simply lay an aluminum foil on the ground with a hole cut out for the plant to come out of.
As a last resort, you can also use certain pesticides like dinotefuran or thiamethoxam.
Holes in Leaves of Bean Plants
Problem: There are holes in the leaves of your bean plant.
The most common culprit behind the holes in the leaves of bean plants are caterpillars. As you most likely already knew, a caterpillar is the larval stage of a butterfly or a moth. Female butterflies and moths tend to lay their eggs on the leaves of various plans, beans included. When these eggs hatch, the caterpillar chews on the leaves so that it can move on to the next stage of its life cycle.
The fix for caterpillar infestation is to prevent butterflies and moths from laying eggs on your plants.
Snails and Slugs
Two other common culprits behind this problem are snails and slugs. These mollusks usually come out after sunset and feed on the leaves, pods, and stems of various plants, bean plants included. There is a sure-fire way to confirm if these are indeed your culprits. Both these mollusks tend to leave a white trail down their path. So if you find this, you can take the necessary measures.
The best fix for snails and slugs is to encircle the area with your plants with some copper wire. The copper reacts with the slime to create an electric shock that will deter the mollusks from entering the area. You should also avoid over-moisturizing the area, as such areas can breed snails and slugs.
Bugs & Insects
The other culprits behind the holes in the leaves of your beans are bugs and insects. Sap sucking insects like spider mites, aphids, and whiteflies, if left unchecked, will leave your leaves with holes in them.
Bigger bugs such as bean weevils, cucumber beetles, darkling beetles, etc. are also responsible for the holes in leaves. Unlike the smaller insects, the effect is more direct with these bigger bugs as they like to chew on the leaves.
To check the smaller insects, you can keep predatory insects such as ladybugs in the area. For the bigger bugs, the only thing you can do is to regularly check for them or their eggs and remove them as soon as detected. Maintaining good sanitation can also help prevent bug and insect infestation.
Bean Plant Not Flowering
Problem: Your bean plants are not blooming, and consequently are failing to produce pods.
The most common reason why beans fail to produce flowers is that they are not raised in the optimal environmental conditions. Although they are much easier to grow than most plants and vegetables, beans do require certain conditions.
The temperature of the soil, for instance, needs to be maintained between 16 and 24°C (60 – 75°F). For this, you need to choose a location that gets plenty of sunlight. Also, you need to provide your plant with sufficient water.
This is a common mistake a lot of beginners tend to make. Using a lot of fertilizers can prevent beans from blossoming. This is because beans like all legumes are capable of extracting some nitrogen directly from the air. This is different from most plants that get almost all of their nitrogen from the soil.
So beginners, using this same logic, tend to use a lot of nitrogen fertilizers with their bean plants. Too much nitrogen will result in the beans failing to produce flowers.
The fix for this problem is to check the soil before using any fertilizer. If the soil has a decent amount of nitrogen in it, you should avoid adding any more fertilizer.
There could be another, much simpler explanation as to why your beans are failing to produce flowers. If the plant is under a month old, it just needs more time. You have to wait at least four weeks for your bean plant to start producing flowers.
The plant may look like it is mature, but it still needs a month before it can start producing.
Stunted Bean Plant and Pods
Problem: Your bean plant fails to grow beyond a certain size, or it produces very small pods.
The main reason you are getting stunted bean plants and pods are adverse environmental conditions. Beans are summer plants, meaning they require a certain amount of warmth and moisture to flourish. But too much of either can be a bad thing.
If your bean plant gets exposed to too much warmth, it could result in stunted growth and, subsequently, stunted pods.
Also, if bean plants get exposed to too much moisture, they stand the risk of being infested by a range of insects and pests, which could adversely affect its growth. This, too, could result in a stunted plant.
Thus, to fix the problem of stunted plants and pods, you need to make sure your beans get the optimal conditional. The beans you get in the market are grown under these optimal conditions of temperature, soil, spacing, and water. Keep the soil temperature between 16 and 24°C. Plant your seeds at least 3 inches (8cm) apart, and avoid overwatering your plants.
Bean Plant Flowers Falling Off Without Making Pods
Problem: Your bean plants are blooming, but the flowers fall off without making pods.
Most bean species are self-fertile plants, meaning they do not require the help of pollinators like bees. But some are not, and in the absence of sufficient pollinators, the flowers will just fall off without flowering
To fix this problem, first, check to see if your breed of beans is self-fertile. And even if they are, having some pollinators can help improve the changes. So make sure your plants are accessible to pollinators.
Beans like all legumes, don’t require too much fertilizer. If your plant is being fed too much fertilizer, it could result in the flowers falling off without making pods.
Make sure to check the nitrogen content of the soil and only add some fertilizer if it is too low.
Insects and Pests
If your bean plants are being infested with too many insects and pests, it could result in them failing to make pods. Insects and pests like spider mites, whiteflies, caterpillars, slugs, snails, beetles, etc. not only damage the leaves and stems of the bean plants, but they can also prevent the flowers from making pods. These insects also sometimes carry viruses that can adversely affect the plants.
To fix the problem with insects and pests, you should always first resort to preventing the infestation. Introducing predatory insects like ladybugs to the vicinity can also be useful.
Not all insects are bad for these plants (as we had seen when we discussed pollinators). So you shouldn’t jump right into using pesticides.
Bean Vines Wilting
Problem: The vines of your bean plants are wilting.
The most common reason behind wilting vines in bean plants is some sort of injury to the plant at its base. While beans and most legumes get a share of their nitrogen from the air, they still very much depend on their connection to the soil for a range of other minerals.
If the stem has been injured around the bottom, this could result in a lack of sufficient nutrients flowing to the top of the plant through the vines. This could result in the vines wilting.
To fix this problem, make sure your plant’s base is sufficiently secured. It also makes sense to give the base some extra support via a frame of some sort.
Adverse environmental conditions are a common cause of a whole range of problems with beans. Wilting vines are no exceptions. If the temperature exceeds a certain level or the plant doesn’t get the necessary moisture, this could result in the whole plant failing to continue its growth via the vines.
To fix this problem, water the plant based on the temperature. When temperatures are favorable, water it as usual. But when temperatures increase, give the plant more water. Also, avoid using fertilizers when the temperature exceeds the recommended level.
Diseases & Pests
Diseases and pests continue to affect bean plants to a certain extent, even after they have fully grown into vining plants. And under severe conditions, certain pest infestations can result in the wilting of the vines.
Sap sucking insects like spider mites and whiteflies are some common culprits that continue to trouble a bean plant throughout its life. These insects also carry viruses sometimes, which can make things worse.
To fix this, consider using a small amount of pesticide. Once the plant is fully grown, it can usually handle some pesticide. Also, consider introducing predatory insects like ladybugs to the vicinity.
We looked at seven of the top common problems growing beans and the fix for each of them. The top common problems include leaves turning yellow/brown, leaves curling, holes in the leaves, plants not flowering, flowers falling off without making pods, stunted plants and pods, and wilting vines.
The recurring culprits in most of these problems include viruses, bacteria, insects, bugs, pests, and above all, adverse environmental conditions. Beans are some of the easiest vegetables to grow. With the right amount of precaution, you can guarantee a good harvest.