Rainy Weather and Warm Temperatures! Help!

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Spring showers brought May flowers but as we approach the month of June and July disease can begin to set in all over the home landscape due to the repeated rain events and warmer temperatures. Fungal pathogens are the result of these wet and warm conditions.

Typically the first indication of fungal disease in the home landscape is brown patch in your lawn. Brown patch disease can develop rapidly when daytime temperatures are warm (75 to 90°F) and humid, nighttime temperatures are above 60ºF, and there is an extended period of leaf wetness. Symptoms begin in cool-season grasses like Tall Fescue in late spring. Warm-season grasses are not immune, symptoms show in late spring/early summer to late fall. Last week and this week are the ideal weather conditions for brown patch for form.

Brown patch diseases show symptoms on the lawn. These symptoms include thin patches of light brown grass in circular shapes. These will first show up in low spots, poorly drained areas, and shady areas.

There is not a cure for fungal diseases only preventative products like fungicides which are costly and are not curative.

PREVENTATIVE MEASURES and growing a healthy lawn are your best mode of action to prevent fungal lawn diseases:

  • Soil test and apply fertilizer correctly. Excess fertilizer can lead to disease. Remember to not fertilize tall fescue lawns after March 15th. The disease can be more severe is the soil pH is less than 6.0.
  • Keep lawns mowed regularly and at the proper height. Do not mow fescue lawns shorter than 2½ inches high, nor higher than 3½ inches. Low mowing height on tall fescue will increase disease.
  • Address drainage issues with core aerification and mitigating any standing water in the yard by leveling low spots.
  • If you have an irrigation system attach and sync a rain sensor to prevent the lawn from being irrigated and rained upon. Tall fescue needs 1 inch of water per a week.

For more information: Brown Patch in Turf

Fungal pathogens not only affect your lawn but ornamental plants as well.

Tips to prevent disease in ornamentals:

  • RIGHT PLANT IN THE RIGHT PLACE! This is essential, plant shade plants in the shade and sun plants in the sun. Water-loving plants in low spots or near water sources and dry plants in full sun and dry spots.
  • Containers: Make sure your container has proper drainage at least one hole in the bottom or more. Move containers undercover during heavy rain events to prevent saturation and damage.
  • Air Flow: Overcrowded planting beds do not allow for adequate airflow and will promote disease. Plant according to recommend spacing and prune shrubs according to prevent overcrowding and increase airflow. Mulch is a benefit in the garden if applied at a 2-3 inch layer anymore and you will suffocate the plant.

Trees!

  • Older urban trees are at a higher risk during repeated rain events when the soil becomes saturated and thunderstorms with high winds roll in.
  • Fallen trees can be devastating, take preventative measures, and hire an arborist to care for your large trees surrounding your home.

For information on arborists: How to Hire a Tree Care Professional

Take home! Rain happens, as we have more periods of rainy events you may have plants succumb to fungal diseases, and worst of all some may die. Phytophthora root rot is the worst pathogen of all and is a death sentence to many plants in the landscape. To learn more: Phytophthora Root and Crown Rot in the Landscape