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Summer Patch

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  • Affects mostly blue rye; seldom tall fescue

  • Most common during July thru September (higher humidity and warmer weather)

  • Main cause — Keeping the leaf surface continuously wet (daily watering), low mowing heights

  • Symptoms — Initial symptoms are 4-6 inch oval patches of orange-brown grass, which can grow to 12 inches. The patches are often clustered with a small clump of green grass growing in the center of each patch. Fungal threads do NOT form within the leaf mat. Most severe in sunny, heat stressed slopes or strips adjacent to walls that reflect heat

  • Cultural Practices —  to minimize chances of disease:

  • Avoid applying high rates of Nitrogen, particularly in late spring and summer

  • Water during early AM hours to allow grass leaves all day to dry off

  • Avoid frequent irrigation that keeps the leaf  blades wet and that results in water-logged/compacted soils

  • Mow at the upper end of recommended mowing heights (but not above recommended mowing heights)

  • More prone in compacted, wet soils (clay soils)

  • Spray on a fungicide labeled for Summer Patch if symptoms appear… repeat every 10 days until symptoms are gone...ALWAYS READ & FOLLOW LABELED DIRECTIONS!