Hydroponic Peas Turning Yellow: Heat Plus Root Problems
Hydroponic peas turning yellow often point to a room that runs too warm or roots stressed by warm, poorly aerated water. University of Minnesota Extension lists 55 to 65F as good growing temperatures for peas. Cool the space, check the roots for rot plus confirm the nutrient solution pH is in range.
The short answer
Peas are a cool season crop. University of Minnesota Extension gives 55 to 65F as good growing temperatures and notes that peas stop growing above 85F. NC State Extension adds that root rot plus fusarium wilt can make plants wilt and die. Cool the room, inspect roots plus check pH plus dissolved oxygen in the solution.
How does heat affect peas?
University of Minnesota Extension notes that peas grow well between 55 and 65F. They stop growing and will not produce flowers or pods once temperatures rise above 85F.
Peas need full sun, the same source adds, but peas produced in hot weather may have poor quality. NC State Extension also notes that powdery mildew can occur in hot weather on leaves plus pods.
Indoors, a cool room with bright light suits hydroponic peas.
Why do root problems cause yellowing?
NC State Extension notes that root rot plus fusarium wilt are common ailments that can cause roots plus plants to wilt and die. Some varieties resist root rots plus powdery mildew, University of Minnesota Extension adds.
Colorado State University Extension explains that hydroponic root rot shows as brown roots with sparse root hairs. Low oxygen in the solution favors disease, and the optimum root zone temperature is 68 to 72F.
Most root pathogens hit plants that are already stressed, the same source notes. A pea plant in a warm room with warm water meets both stresses together.
| Condition | What Extension notes | Response |
|---|---|---|
| 55 to 65F | Good growing temperatures | Aim for this range |
| Above 85F | Peas stop growing plus set no pods | Cool the room |
| Brown roots with sparse root hairs | Root rot | Aerate plus cool the solution |
| pH outside 5.5 to 6.5 | Poor nutrient uptake | Adjust pH |
Source: University of Minnesota Extension plus University of Missouri Extension.
Could the nutrient solution be the cause?
University of Missouri Extension explains that plants may not take up all nutrients when pH is outside the optimum range. Its rule of thumb for most hydroponic crops is pH 5.5 to 6.5.
Water temperature caps how much oxygen water can hold, the same guide notes. Warmer water carries less. Deep water culture systems need dissolved oxygen plus water temperature checks.
NC State Extension notes that peas fix nitrogen in soil. In a hydroponic solution, check pH plus EC before adding more fertilizer.
How to: step by step
- Read room temperature plus aim for 55 to 65F.
- Move plants to a cooler room if temperatures pass 85F.
- Lift a plant plus inspect roots for brown color.
- Raise aeration plus hold the root zone near 68 to 72F.
- Check pH plus EC of the solution.
- Pick root rot resistant varieties for the next crop.
Troubleshooting
Yellow in a warm room: heat. Cool the space.
Yellow with brown roots: root stress. Cool plus aerate.
Flowers plus pods stop forming: heat over 85F. Lower the temperature.
For related reading see how to spot 8 common cannabis plant deficiencies by leaf symptoms, hot pots root zone heat in cannabis containers plus cannabis heat stress. Kind Seed Co also stocks cannabis seeds.
Sources
- Growing peas in home gardens, University of Minnesota Extension
- Lathyrus oleraceus (garden pea), NC State Extension Gardener Plant Toolbox
- Hydroponic nutrient solutions (G6984), University of Missouri Extension
- Root disease problems plus management in hydroponic systems (PlantTalk 2043), Colorado State University Extension
FAQ
Do peas need support in hydroponics?
Yes for vining types. University of Minnesota Extension notes that the vines need a trellis to support them as they climb. NC State Extension adds that vining varieties grow well on a trellis such as stakes plus twine, which also helps minimize disease. Bush types can support each other.
Why are my peas not flowering?
University of Minnesota Extension notes that peas stop growing and will not produce flowers or pods once temperatures get above 85F. Good growing temperatures are 55 to 65F. Cooling the room is the first step when hydroponic peas stall without flowers.
How long do hydroponic peas take?
University of Minnesota Extension notes that most pea varieties need about 60 days of growth before harvest. NC State Extension agrees that plants often reach the harvest stage in 60 days. Plantings can be staged a week apart for a longer harvest season.
Are some peas resistant to root rot?
Yes. University of Minnesota Extension notes that some varieties are resistant to common pea diseases, including root rots plus powdery mildew. NC State Extension lists root rot plus fusarium wilt as common ailments, so resistant varieties are worth choosing for a hydroponic crop.
What pH suits hydroponic peas?
University of Missouri Extension gives pH 5.5 to 6.5 as a rule of thumb for most hydroponic crops, with exceptions. Outside the optimum range, plants may not be able to take up all the nutrients in the solution. Check pH regularly with a meter.
