What to do now
Mildest step first.
- Check the weather and the calendar: if it has turned hot and you've been picking for weeks, the plants are likely finishing, so pick what's left.
- Pull one yellow plant and look at the roots: healthy ones are white with small nodules; brown, soft or shredded roots mean root rot.
- Let soggy beds dry out, and pull plants with rotted roots, orange or red streaks inside the stem, or mottled new leaves; put them in the trash, not the compost.
- Next season, plant peas early, in a different well-drained spot, and choose varieties resistant to wilt and powdery mildew.
Not sure this is it? Check other pea problems
Read the pattern
When pea plants turn yellow, where it starts and what the weather has been doing say the most. Yellowing that arrives with the first hot weather, after weeks of picking, is usually the end of the season. Yellowing from the bottom up on stunted plants, often in patches in the wettest part of the bed, points to root rot. Yellow leaves that curl downward, with discolored tissue inside the lower stem, suggest Fusarium wilt. Mottled, distorted new growth suggests a virus, and a white powdery coating before the leaves yellow is powdery mildew.
Heat and the end of the season
Peas are a . Utah State notes that they do poorly when temperatures go above 80°F, and that heat and dry soil cut yields and make plants shed their flowers. The University of California's home vegetable guide lists hot weather as a common reason plants stop producing, with leaves turning yellow, then brown, before they die. Penn State's advice is plain: when the plant turns yellow, it's time for it to go. If the plants were healthy, Penn State suggests cutting them off at ground level and leaving the roots in the soil. Clemson suggests sowing as early in spring as the ground can be worked, which gives the crop more time before the heat.
Root rot
Root rots are the most common disease behind yellow peas. Several soil fungi and water molds are involved, among them Aphanomyces, Pythium and Fusarium. The Pacific Northwest plant disease handbook describes stunted plants whose lower leaves yellow sharply, with gray, reddish or black lesions on the lower stem and roots, and a taproot sometimes rotted to shreds. The University of Minnesota notes that Aphanomyces leaves the stem brown and soft at the soil line and is most common in heavy, wet soil. Not every root rot needs cold soil: the same handbook notes that Fusarium root rot is favored by soil above 75°F. What they share is wet or compacted ground. Washington State suggests well-drained soil or raised beds, not overwatering heavy soil, and removing diseased plants, roots and all, without composting them. Rotation helps, though sources differ on how long: Washington State suggests peas only every third year in the same spot, and the PNW handbook once every 5 years.
Fusarium wilt
Fusarium wilt can look similar from a distance, but it has its own clues. North Dakota State describes leaves that curl and yellow from the base of the plant upward, sometimes worse on one side. Washington State notes downward curling of leaves and stipules and a yellowish to orange discoloration inside the lower stem and roots, while the roots otherwise look normal; one race of the fungus leaves a dark red streak instead. Utah State notes that wilt becomes a problem once soil passes 70°F, so early planting helps. The fungus can survive in soil for 10 years or more, according to North Dakota State, which makes resistant varieties the main defense. The PNW handbook notes that most garden varieties resist race 1, with Little Marvel an exception, and Washington State lists resistant varieties such as Alaska and Early Perfection.
Nitrogen and root nodules
Peas rarely need nitrogen fertilizer. They are legumes, and bacteria living in nodules on their roots supply nitrogen. Clemson cautions that extra nitrogen reduces pod production, and Utah State that it pushes leaves, delays flowering and cuts pod set. If a whole planting is evenly pale and the roots have few nodules, the plants may be short of nitrogen. The University of Minnesota notes that nodules that are working are pink inside, while white ones are inactive, and suggests using an inoculant the first time you grow a legume in a spot.
Viruses
Viruses usually show as mottling or distortion rather than plain yellowing. UC notes that pea enation mosaic and pea streak are common, that both are spread by aphids, and that new growth may be distorted, curled and mottled. Washington State adds that pea enation mosaic can raise small blisters on the leaves, and that pea seedborne mosaic also travels in seed; it suggests certified seed and not planting near alfalfa, which hosts pea streak. There is no cure. UC IPM suggests pulling plants with symptoms, since they won't produce well and may spread the disease, and planting resistant varieties when available. Sources disagree on aphids: UC IPM says spraying them isn't a practical way to control the viruses, while Washington State still recommends keeping aphids down.
Powdery mildew and aphids
Late in the season, a white, powdery coating on leaves and pods is powdery mildew. Utah State notes that the leaves may yellow and drop, that it is too late to control once the leaves are covered or yellow, and that resistant varieties exist. The University of California notes that it is favored by warm, dry days and cool, damp nights. Heavy aphid feeding can also yellow and wilt leaves; Washington State suggests washing aphids off with a strong stream of water.
Growing it again? When to plant pea for your ZIP code
- Root RotPlants wilting despite wet soil, with brown or slimy roots — wet-soil pathogens destroying the root system.
- Fusarium WiltOne-sided yellowing and wilting; stem cut lengthwise reveals brown or salmon-colored vascular tissue.
- Powdery MildewWhite powdery spots on leaves that spread into a floury coating — common when warm, dry days follow cool nights.
- AphidSoft, clustered insects on new growth causing curled leaves and sticky honeydew.
- Brown Marmorated Stink BugSunken, corky dimples on fruit and pods caused by a mottled brown shield bug feeding through the skin.
- Why are my bean leaves turning yellow?Read the pattern. A few old lower leaves yellowing on a plant that's still producing is normal aging. A whole planting gone pale in cold or soggy soil has struggling roots. Mottled yellow-and-green, puckered leaves suggest a mosaic virus. Fine pale speckling that turns yellow in hot, dry weather means spider mites.
- What soil temperature do I need to plant vegetables?It depends on the crop. Lettuce, spinach and onion seeds can sprout in soil as cold as 35°F. Peas, carrots, beets, radishes, cabbage and kale need about 40°F, potatoes 45°F, and corn and tomatoes 50°F. Beans, cucumbers, peppers, squash and melons need 60°F. Seeds come up faster and more evenly when the soil is well above these minimums.