Pythium/damping off mostly occurs when the nighttime temps and relative humidity add up to at least 150. It is an incredibly devastating disease and progresses rapidly, especially under these conditions. I recognize that we cannot always avoid installing lawns when it is hot/humid, but here are a few steps you can take to help mitigate your risk:

  • Avoid heavy seeding rates as this will increase the potential for Pythium.
  • Avoid late day and excessive watering. Extended periods of moisture will bring more harm than good
  • Use fungicides during or shortly after planting. They are very inexpensive in comparison to having to replant.
  • Avoid excessive fertilization. Lush growth will be more susceptible to disease.
  • Do not use high mulch rates when hydroseeding.

We also have seed available from Barenbrug with a coating known as Yellow Jacket. Seed coated with this proprietary material is treated with Apron fungicide, which will protect the seed from Pythium/damping off. Yellow Jacket also provides many additional benefits to aid in lawn establishment, so ask your ATS rep which blends/mixes are available.

A few summers ago, I witnessed a total loss of a new lawn at the hands of Pythium. After the installation was completed, the homeowner actually followed their instructions and watered the turf, which is the most unbelievable part of the story! After seven days, the newly installed turf was doing great. Then without warning, it was dead! The problem was she watered day and night relentlessly, which is why the disease became so severe. It is unfortunate that this is more common with the clients that are liberally watering. Due to the overly saturated seedbed, the lawn went from lush green to dead…overnight! FYI – they seeded at a 10lb/1000 sq.ft. with a 60% Rye 40% blue mix, which equals a 90% dead lawn under these conditions.

Photos from the Pythium-devastated property:



Although you cannot completely eradicate the chances of this destructive disease flaring up, following the above tips will help put you in a better position for success!