Managing bermuda fields for winter after flood
I have two Bermuda fields: one planted May 2015 and one planted May 2016. I have lightly grazed them with horses when it got ~10” for a 1-2 days occasionally. I have mostly managed them through these first yrs by mowing them down to 2-3” as needed (weekly). Last fertilization was 8/1/2016 with 50 lbs N/ac. I do not wish to over seed with rye this year. The stands were looking very good at 8-12” high with very minimal broadleaf weeds & some patches of crabgrass; however the fields were recently flooded for 3 days by Fishing Creek. They are now dry, standing upright but have a fine dirt silt covering so I would not expect horses to graze it well.
Should I mow the fields and if so when and to what height in prep for winter?
I'm sorry to hear your pasture flooded. It sounds like you had a really good stand growing!
You are absolutely right in not wanting to graze your horses on your recently flooded pasture. The silt covering the leaves and stems can lead to impaction and colic, so it's wise to keep your horses out of the pasture for roughly 10 days to give the silt some time to settle.
Bermuda grass should go into the winter with 3-4 inches of growth to serve as insulation against winter damage. Bermuda grass stops growing when the temperatures drops and stays below 80 - like this week, but bermuda grass usually goes completely dormant towards the end of October. I would recommend mowing your bermuda grass in the last week of October for 2 reasons: 1) The tall bermuda grass will help shade out any weed seeds that may have washed into your pasture along with the silt and keep them from sprouting; and 2) the flood may have stressed/weakened your bermuda grass (bermuda grass does not like 'wet feet'), so grazing or mowing your stand could reduce its regrowth next year.
Hope this was helpful! If you have any other questions, please don't hesitate to ask!