Weather & Turf Factors

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Extreme heat and humidity have persisted in the summer of 2010. The wet conditions this spring coupled with the heat stress have combined for peak turf loss conditions. The cold spring and wet conditions (33” April through July ’10) was not conducive to healthy deep root development. The cool season grasses had to survive on reserves in the root system that ran out in August. In addition, high humidity has created constant high fungal disease pressure.

Dew points, temperatures, wind speed, and soil temperature are the key climactic factors which measure the stress associated with cool season grasses ability to perform its basic physiological functions, (respiration, photosynthesis, evapotranspiration). A brief summary of these factors, their critical values, and their occurrence follows for the period of June through Aug 31th.

Days with highs of 90 or above 42
Days with a low temperature above 70 50
Days with a average dew point above 70 51
Days with an average wind speed of 10 mph or less 71
Days in which soil temperatures have been above 86 72

When all five of these factors occur simultaneously at their critical values (highs & lows above 90 & 70 respectively, dew points above 70, soil temps above 86, and wind speed below 10), cool season grasses are in a state of full blown decline. There is no recover for that day. The plant can no longer perform its basic functions normally. Metabolic activity is sustained solely at the expense of the root system. When this occurs for extended periods of time little can be done to alleviate the issue.

Total days in which all five of these factors occurred simultaneously over the last 20 years, (i.e.# of severe root decline days)

Year 90’ 91′ 92′ 93′ 94′ 95′ 96′ 97′ 98′ 99′
# of days 5 8 1 3 2 14 5 10 12 17*
Year 00′ 01′ 02′ 03′ 04′ 05′ 06′ 07′ 08′ 09′
# of days 9 16 13 9 5 7 11 8 5 6

*1999 had the most consecutive days with 13

In 2010 this has happened 36 days.
We felt with the difficulties that your lawn saw this summer, this information would make you better informed. Now that fall is here Brummel Lawn has placed a fertilizer down on your lawn that will help the plant with developing a better root system and providing the nutrition that the plant will need. We also sprayed the weeds that may have invaded your lawn (unless there was fresh seed on the ground which we encourage seeding or aerating) when the turf couldn’t fight them off. Brummel Lawn is committed to 100% satisfaction, please call us with any questions or concerns you may have, and we look forward to continue to serve your lawn needs.

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