The most common causes of yellow leaves on peas are a lack of sunlight, pests, poor soil, diseases like fusarium wilt, underwatering and overwatering. Giving too much water to peas or heavy rainfall can wash nitrogen out of the soil causing the leaves to turn yellow. Pests like aphids and scale can suck the sap from the pea leaves causing them to curl and turn yellow within a few days.
Check the leaves carefully for pests and treat the sap suckers with Neem oil. Yellow leaves on peas can be easily fixed and this article will explore what to do to save your plants.
Top causes of leaves turning yellow on peas
Here are the top reasons why pea leaves turn yellow. Check out each one and see if this might be the cause of the problem for your peas.
1. Old lower leaves
One of the most common reasons that pea leaves turn yellow is when the leaves start to get old at the base of the plant. These older leaves cab start to turn yellow as the plant grows. This is a completely normal process, and the peas will produce larger green leaves at the top of the plant.
These yellow leaves will not cause any harm to the plant and can be left on. The plant will reabsorb the nutrients from these lower leaves and they will eventually shrivel.
2. Lack of nitrogen
Another common reason that pea pea leaves turn yellow is a lack of nitrogen. While peas are legumes so have the ability to fix nitrogen from the atmosphere in very poor soils they can still suffer and turn yellow.
Before planting out new pea plants in very poor, sandy soil, mix through compost, aged cow manure and pelleted chicken manure to increase nitrogen levels.
Overwatering can cause pea leaves to turn yellow. Overwatering will wash nitrogen out of the soil and away from the roots. It can also compact the soil, causing the roots to rot and they won’t be able to get the nutrients they need. Plants that have poor drainage will also develop yellow leaves as the soil stays wet for too long and the wet soil can cause fungal growth on the roots.
Before watering peas check the soil first to see if it is dry 1-2 inches down. Water only when the top soil has started to dry out to avoid overwatering. Rain water is great for peas as it will contain small amounts of atmospheric nitrogen to help them to develop green leaves.
Mulch the plant with bark mulch or straw which will help to regulate the amount of water that runs through the soil. Bark mulch will absorb extra water and slowly release it over time. Slow down your watering schedule and allow time in-between watering for the soil to dry out slightly.
4. Pest attack
Pests can cause pea leaves to turn yellow. Sap sucking insects such as scale or aphids can sit on the leaf veins, sucking out the nutrients and water and causing damage to the leaf. The leaf will eventually turn yellow and then brown.
Scale are small beetle shaped insects which will suck the sap from your pea leaves. Scale can be treated with Eco or Neem oil effectively. Spray the bugs off with a strong jet of water if there are only a few but check your plant each day because they can quickly breed and take over.
Small green aphids can attack peas sucking their sap and causing leaves to turn yellow. These insects will attack new growth and can appear quickly in the mild fall weather. Ladybugs will move in to eat the aphids if there are only a few. If the population gets large, spray them with Neem oil. Aphids can cause damage to young peas so deal with them quickly.
Spider mites are tiny arachnids that can attack your pea plants. These pests feed on plant sap, piercing pea leaves with their needle-like mouthparts, causing the leaves to turn yellow and eventually leaf drop. When spider mite populations get large they can significantly stunt plant growth and reduce pea yield.
To get rid of spider mites use an insecticidal soap or Neem oil. Spray the leaves to keep the mites away. Stop spraying your plants 2 weeks before you want to harvest your crop.
Underwatering can cause your pea leaves to turn yellow. Peas growing in sandy soil can also dry out quickly as the soil is unable to hold the water for long. Unseasonal hot weather can lead to a lack of water for your pea plants, causing the leaves to turn yellow and then brown. These are great cool weather plants but if you get a sudden hot spell, make sure you add extra water to keep the peas happy. A little water regularly is a good way to keep them happy if the weather warms up.
Regularly water peas if the weather is warm. Consistent water will help to prevent yellowing leaves on peas over spring and summer.
6. Lack of sunlight
Peas that do not get enough sunlight can start to develop light green or yellow leaves. Peas will grow best and fastest when they get at least 6 hours of sunlight. This will help the green chlorophyll to develop in their leaves and encourage flowers and peas to form. If you are growing peas in pots, move them into a position that gets direct sunlight in the morning. This will help the plant to grow faster and photsynthesize efficiently.
7. Fungal disease
There are several diseases that can cause yellowing of pea plants. Fusarium wilt is a common fungal disease that can cause yellowing, dark spots, stunting, and wilting of the entire plant. This disease lives in the soil and can enter through the roots of the plant.
Root rot and powdery mildew are also common diseases that can cause yellowing of the leaves. Crop rotation is a great way to stop peas from being re-infected year to year. Choose a new space in your garden each year for your pea crop to keep them healthy.
Fungal infections like powdery mildew, downy mildew, or leaf spot diseases can lead to brown spots and yellowing of pea leaves. These pathogens thrive in moist conditions and can be managed with proper spacing, ventilation, and fungicides if necessary.
To prevent diseases, make sure to plant your pea plants in well-draining soil and avoid overwatering. Water your plants at the root zone rather than on the leaves to reduce the chances of fungal growth. You can also use fungicides to help prevent the spread of fungal diseases. You can also remove infected plants as soon as possible to stop fungal disease from spreading.
8. Pea Mosaic Virus
Pea mosaic virus can cause the leaves of infected pea plants to turn yellow. Yellowing is a common symptom of mosaic virus infections in peas, along with the characteristic mosaic pattern of light and dark green areas. The yellowing occurs because mosaic viruses disrupt the plant’s ability to photosynthesize efficiently. As a result, affected leaves cannot produce chlorophyll properly, which is necessary for the green color associated with healthy leaves.
Prevention is best for mosaic virus as there is no cure. Mosaic viruses are often spread by aphids so controlling them is key. Use insecticidal soaps, Neem oil, or beneficial insects like ladybugs and lacewings. Get rid of any plants that you think my be infected including any plant debris. Put them in your garbage bin rather than your compost to avoi
Solutions for yellow pea leaves
In this section, we’ll discuss some of the most effective ways to combat yellowing pea leaves.
Overwatering is one of the main causes of yellowing pea leaves. To prevent this, make sure you’re not watering your plants too frequently. Only water them when the top 1-2 inches of soil are dry. Make sure your peas are growing in well draining soil as waterlogged soil can also cause yellowing. Use good quality potting soil and improve your garden bed with organic matter before planting pea seeds.
If your pea plants are lacking key nutrients especially nitrogen they can quickly turn yellow. I like to add a handful of pelleted chicken manure a month after planting to feed them as they grow. You can also add an organic liquid fertilizer to give them a nitrogen boost if their leaves start to yellow as they grow.
Yellowing pea leaves can also be a sign of disease. To prevent this, make sure you’re planting disease-resistant varieties of peas, examples include Green Arrow, Little Marvel, Sugar Ann, Strike, Early Perfection and disease resistant sugar snap peas. Remove any plants that have been infected and an organic fungicide to help control it.
Pests such as aphids and spider mites can also cause yellowing pea leaves. To prevent this, make sure you’re inspecting your plants regularly for signs of pests. If you do notice pests, try Neem oil or horticultural soaps to control them. I also find that a sharp squirt of water from the hose can quickly remove pests from pea leaves.
3. Move potted pea plants into the sun
If your pea plants are in shade, move the pots into a sunny position. They will develop greener leaves and more flowers to give you plenty of peas over the winter season.
How to stop pea leaves from turning yellow
Here are some things you can do to stop pea leaves from turning yellow.
Regular monitoring of your pea plants is essential to prevent yellowing of leaves. Check the soil to make sure it is not too wet or dry, check the leaves for pests or disease and check the plant for any signs of yellowing. Treat pests, water the plant if it is dry and make sure it is in at least 6 hours of sunlight per day.
Maintain the soil
Maintaining healthy soil is crucial to prevent yellowing of pea leaves. Make sure the soil is well-draining and rich in nutrients. You can add compost or organic matter to the soil to improve its quality before planting to top dress established pea plants with compost around their root zone. Avoid overwatering, as this can cause root rot, which can lead to yellowing of leaves.
Proper plant spacing
Proper plant spacing is essential to prevent the spread of yellowing leaves. This will allow good air circulation and help to prevent fungal and viral diseases as well as pests.
By following these measures, you can prevent yellowing of pea leaves and ensure healthy growth of your plants. Remember to monitor your plants regularly, maintain healthy soil, and provide proper plant spacing.
Yellow leaves on peas | Summary
There are many possible causes of yellow leaves on pea plants including underwatering, overwatering, fungal disease or pest attack. If the issue is a lack of nutrients or water you can usually save your plants. Peas are hardy and will recover once they are given the nutrients and water they need. Treat diseases and pests quickly before they spread and you will be able to save your crop.
Frequently Asked Questions
What causes yellowing of pea leaves?
Yellowing of pea leaves can be caused by several factors, including old lower leaves, nutrient deficiency, overwatering, diseases, and pests.
How can you prevent pea leaves from turning yellow?
To prevent pea leaves from turning yellow, make sure to provide your plants with adequate nutrients, water, and sunlight. Avoid overwatering and ensure proper drainage. Keep an eye out for signs of diseases and pests and address them quickly.
What are the signs of overwatering pea plants?
Overwatering can cause yellowing of leaves, wilting, and root rot. Signs of overwatering include waterlogged soil, slow growth, and yellowing leaves. To prevent overwatering, make sure to water your plants only when the soil is dry to the touch 2 inches below the surface.
What is the best way to treat root rot in pea plants?
Root rot is a fungal disease that affects the roots of plants, causing them to rot and die. To prevent root rot, make sure to provide your plants with well-draining soil and avoid overwatering. If your plants are already affected by root rot, remove the affected parts and treat the remaining plant with a fungicide.
What are the common diseases that affect pea plants?
Pea plants can be affected by several diseases, including Fusarium wilt, Ascochyta blight, and downy mildew. These diseases can cause yellowing or browning of leaves, wilting, and stunted growth. To prevent these diseases, make sure to provide your plants with proper care and address any signs of disease promptly.
How long can pea plants produce before they die out?
Pea plants can produce for several weeks to several months, depending on the variety and growing conditions. It is important to harvest your peas regularly to encourage continued production. Once the plants have finished producing, they will begin to die out.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.