The main cause of green bean leaves turning yellow is an incorrect watering schedule, either too much or too little water can cause a lot of problems.
If you are sure that your green bean plants are getting the correct amount of water, some other causes you can look into including a lack of sunlight, improper spacing, nutrient deficiencies, disease, or pests.
This article will go through these common concerns and help you find out which one is causing your plant to turn yellow, and tell you what you can do to fix it.
I truly think green beans with their fresh flavor and juicy snap are the best vegetables to grow in the garden, and they take surprisingly little effort for such a good return. But when they are struggling, you may notice their leaves turning yellow.
Also known as common beans or French beans, they can be eaten in a variety of ways, and are a great source of vitamins K and B, and folate. I’d recommend anybody to start growing and eating them in their garden.
If you’ve already added these to your garden and are having trouble, find some advice in the guide below.
Getting the right amount of water is pretty important for green beans. Yellowing leaves may be the first warning sign a plant gives out when it is getting either too much or too little.
In general, green beans need 1 – 1.5 inches of water per week, and you must let them dry out completely between waterings. Don’t water them during periods of heavy rain.
It is best to water green beans in the morning, and, if possible, use an in-ground watering system rather than watering them from above. This prevents disease-causing dirt and water from splashing up and onto the plant’s leaves.
Water acts as the transportation system that gets all of the nutrients the plant needs to the right places. Without this, the plant will begin to use up its nutrient supply and slowly yellow and die.
Green bean plants that aren’t receiving water will fail to flower and you won’t get a good harvest if you leave them overwatered for too long in the season.
Overwatering leaves the green beans sitting in wet, soggy soil and this can cause a host of problems that will cause the green bean to become sickly and yellow.
Too much water in the soil can prevent the bean from taking up the nutrients it needs from the soil, essentially suffocating the plant. Overwet soil can also lead to root rot and the moisture can also attract pests.
Fixing the Problem
The obvious answer here is to correct the watering schedule. If you are experiencing heavy rain and your beans are already suffering the effects of overwatering, you can invest in waterproof covers for them.
If you suspect root rot, check for this. You will see that parts of the roots have become mushy and dark. Cut these away and replant them in fresh soil.
Lack of Sunlight
Beans need at least 4 to 6 hours of direct light a day and do best if they receive 8 to 10. This higher level of sunlight will result in a bigger crop. Without enough light, the leaves will yellow and they won’t produce food in the summer.
There is no fix to this problem except to find a sunnier spot for the beans. If you cannot move them, take this one as a learning moment and plant the beans in a sunnier spot next year.
This is another thing to get right when planting your green bean rows. Make sure you space green beans 1 or 2 inches apart when planting, and then space them out to 2 or 3 inches apart as shoots.
If you leave them too packed together, some beans might not be able to get the right nutrients and you will need to pull some unhealthy ones out to save the others.
Don’t worry if this has happened, becoming an expert gardener doesn’t happen without some mistakes to learn from! Make sure to space the beans out properly when you plant in the next season.
Alkaline soil may cause iron chlorosis, which will turn green beans yellow. You can check for this by pouring vinegar on the soil. If it bubbles, the soil is alkaline. Add chelated iron to address this deficiency in the plant.
Improper fertilization can also lead to a lack of nitrogen in the green bean plants, causing the leaves to turn either light green or yellow. Use a low-nitrogen 6-12-12 fertilizer to get your beans the right food.
The most common diseases affecting green beans are blight and the mosaic virus. Blight will cause yellow spots to appear on the leaves. The mosaic virus will first cause water spotting on the edges of the leaves. They will then dry out and turn yellow or brown.
Unfortunately, there is no cure for these conditions. If you see signs of disease on a plant, remove it immediately to stop it from spreading. Destroy the plant and do not add it to a compost heap.
Like all garden crops, green beans are susceptible to infestation from pests. Bean leaf beetles, Mexican bean beetles, vegetable leafminers, and cutworms are all possible culprits if you spot holes in the leaves.
Other insects destroy the health of green beans by feeding on their sap and taking their nutrients. These include aphids, potato leafhoppers, thrips, and two-spotted spider mites.
The best way to control pests is to practice good garden hygiene and by introducing natural predators like ladybugs, green lacewings, and hoverflies.
If you need a quicker fix, use neem oil or an organic insecticidal soap to clear the infestation from the plant. Many pests can also simply be removed by hand, or with a sharp blast of water.
Frequently Asked Questions
Want to know more about green beans? Here are the answers to some other common questions.
Q: What’s the best way to cook green beans?
A: Green beans are best cooked quickly and at high heat, making steaming or sautéing the best methods.
Q: Which month should I plant green beans?
A: Springtime is the best time to plant green beans.
Q: Do green beans regrow after picking?
A: Yes! During harvest time you should get new beans regrowing every few days.
Green Bean Leaves Turning Yellow – Conclusion
As you can see, many problems causing yellow green bean leaves are easily fixed and you can still receive a good harvest of tasty green beans from the plant this year once the issue has been resolved.
Go through each problem in order, and rule out each concern before moving on to the next one. This way, you can quickly find the cause of your beans’ poor health and get back to enjoying your summer garden!
Have other issues with yellowing plants? Check out our guides on what to do if your Sunflower or Dill are yellowing.