Wet Soil Versus Good Soil

• Heavy clay soils are generally not the most suitable environment for plants. Clay retains water and does not allow it to drain and give plants a chance to dry out a bit. If you plant seeds in clay soil that you have not amended with organic materials, it's possible they might rot in the ground before they sprout into the plant you want.
  
  

Plant Diseases That Cause Seeds to Rot

• Fungal diseases are more common in wet soil than in well-draining soil that contains organic materials such as compost. Pythium, Fusarium, Diplodia, Rhizoctonia and Penicillium are fungi that live in soil, according to the University of Missouri. If any of these fungi are present, corn seeds have been shown to rot before they germinate.
  
  

Preventing Rotted Seeds

• Amend clay soil with plenty of organic materials such as any type of compost, sawdust, leaf litter, lawn clippings and disease-free plant parts. Keep the soil in your newly planted seeds' area damp, but allow it to dry out a bit between waterings. If the weather is not extremely hot, water seeded areas two to three times each week. You might be able to reduce watering after plants are several inches high, depending on the type of plant.