So, you decided to grow bush beans to enjoy their delicious flavor and countless nutrients. You’ve put in the effort to provide these plants with the ideal growing environment.
All of a sudden, the color of their leaves starts changing. Now you’re full of questions: Why are my bush beans’ leaves turning yellow? Is this treatable? What can I do to stop this?
Well, these are the questions I aim to answer today. Let’s get right to it!
What Prompts the Leaves of Your Bush Beans To Turn Yellow?
Let’s see all the factors that prompt your bush beans’ leaves to turn yellow.
1- Insufficient Sunlight
Think of absorbing sunlight as bush beans’ full-time job. They need 8-10 hours of sunlight exposure a day, or they won’t be able to produce chlorophyll.
It’s a pigment that turns sunlight into chemical energy that your plant can feed on. Without it, your plant won’t be able to carry out photosynthesis, which would prompt the leaves to turn yellow.
If your bush bean isn’t receiving enough sunlight, the yellowing will start from the leaves at the bottom, as they’re the farthest from the sun. Over time, the rest of the leaves will follow, and the plant will die.
Besides, without sufficient sunlight, the water in your plant won’t dry, which prompts fungal infections. These can cause the leaves to wilt and lose their color.
2- Improper Soil
Soil is a plant’s house. It’s an accommodating environment that it’ll sit in for a long time. So, you want to ensure it’s as welcoming and comfortable as possible.
You know how people have different tastes when it comes to decorating houses? Well, plants have different soil preferences depending on their water and nutrient intakes.
If your soil isn’t mixed specifically for your bush bean, it won’t provide it with the necessary nutrients to grow properly, prompting the leaves to turn yellow.
3- Poor Watering Schedule
Watering plants isn’t as simple as movies make it out to be. You don’t just wake up every day and water your plant first thing in the morning.
Like soil, different plants require different water intakes. Some need water every two weeks, while others need it every month.
Here’s the problem: Identifying when your plant needs water isn’t as easy as it sounds. That’s why many new plant owners end up over/underwatering their plants.
Overwatering your bush bean is the easiest way to suffocate its roots. That means they won’t be able to absorb water and transfer it to the leaves.
As a result, the foliage will turn yellow from dehydration. Underwatering is just as bad.
If the roots don’t receive enough water, they’ll die from dehydration. So, they won’t be able to transfer nutrients to the leaves, prompting them to turn yellow.
4- Lack of Nutrients
Watering your plant isn’t the only way to supply it with nutrients. Fertilizing can help it go a long way.
In fact, without fertilizing, your bush beans might face nutrient deficiency, which would cause the leaves to turn yellow, so don’t skip it.
5- Temperature Fluctuations
You wouldn’t be able to function at full capacity under extreme weather, right? The same thing goes for bush beans.
If the temperature is too high, the leaves of your plant will face potential burns, which prompt them to turn yellow. On the other hand, low temperatures can stunt the leaves, which would also cause them to lose their color.
6- Diseases
Yes, plants are susceptible to various diseases. I’m not talking about a cold or a flu, but bacterial and fungal diseases.
Bacterial Diseases
The most common/threatening bacterial disease bush beans face is blight. It prompts the development of brown lesions on the leaves, which prevent the plant from photosynthesizing.
As such, it won’t receive the necessary nutrients to grow properly, and the leaves will turn yellow.
Fungal Diseases
You’ve probably heard of white mold and how it targets various types of plants. Well, your bush beans are no exception.
Like blight, white mold can hinder the photosynthesis process, causing your leaves to weaken and turn yellow.
7- Pest Infestations
Unfortunately, bush beans aren’t pest-resistant. Aphids, thrips, and two-spotted spider mites are all serious threats.
These can suck the sap out of your bush beans’ leaves, causing them to wilt, turn yellow, and fall off.
8- Crowding Your Bush Beans
Some gardeners make the mistake of planting too many bush beans right next to each other to get the most crops when they harvest them. That’s a recipe for disaster.
You see, growing too many bush beans in a limited space prevents each one from growing to its full potential. They’ll be absorbing water, fertilizer, and nutrients from each other.
As a result, some, if not all, plants won’t get enough nutrients to grow properly, losing their vitality, wilting, and turning yellow.
How to Prevent Bush Beans’ Leaves from Turning Yellow
There’s no point in learning what causes your bush beans’ leaves to turn yellow if you won’t prevent it. Let’s see what you can do.
1- Move Your Plant Somewhere Sunny
If the leaves of bush beans are turning yellow because you’re growing them in a shaded area, the obvious solution here is to move them somewhere sunny.
You want bright, direct sun exposure. So, your best bet is to grow it in an open area or in front of a south-facing window. It receives a lot of direct sunlight, so it’ll fulfill your plant’s sun exposure needs.
2- Use Well-Draining Soil
Bush beans hate sitting in water. So, you want to use well-draining soil that retains enough moisture to keep the plant hydrated but drains excess water to prevent root rot.
Ideally, your soil’s pH levels should range between 6-7 to provide the plant with proper nutrients. You might also want to add some compost to the soil to improve its nutrient retention abilities.
3- Water Your Beans Consistently
Watering bush beans is challenging, but there’s a simple method you can use to determine if it needs water.
Touch the top two inches of the soil. If it’s dry, give it some water. If it’s still moist, wait until it dries.
I understand determining whether the soil is dry enough or not might be difficult for new plant parents. So, I recommend using a moisture meter.
It’s a small device that measures the moisture levels in the soil, so it might make the process easier.
4- Control the Temperature
You want to keep your bush beans somewhere with temperatures ranging between 65°-85℉. That’s the perfect range that allows your plant to go through photosynthesis, respiration, and germination at an optimal pace.
5- Protect Your Plant from Pests
The most organic method of managing pest infestations is to drop a few beneficial insects around your plant. Ladybugs, wasps, and hoverflies would be ideal.
These will feed on the pests, ridding your plant of the threat that causes it to lose its color. Pesticides and insecticidal soaps are also effective pest repellents if you want to go the chemical route.
6- Leave a Space Between Your Plants
Don’t overcrowd your soil with excess plants. Leave at least three inches between each plant and 18-30 inches between each row.
That way, you’ll ensure every plant has the space to absorb enough nutrients, water, and sunlight to grow healthy leaves.
7- Fertilize Your Plant Properly
Bush beans can produce nitrogen themselves. So, use fertilizers with low nitrogen levels to ensure your plants don’t grow excess foliage.
Applying fertilizer once a month should be enough. You want your fertilizer to be rich in zinc, magnesium, and iron.
8- Treat the Diseases
You can avoid bacterial and fungal infections by taking extra precautionary measures during the planting and growing phases.
For example, you can treat the seeds of your bush beans with an antibiotic before planting them to reduce the chances of future blight infections.
You can also mix two tsp of neem oil and half a gallon of water to make a natural insecticide that eliminates white mold.
Final Thoughts
The next time your friend asks you why their bush beans’ leaves are turning yellow, you’ll know what to say.
It’s a complicated question, and various factors can prompt that discoloration, whether it’s soil, inconsistent watering, pests, etc.
So, gradually work your way through these potential causes until you fix the problem.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.