Prepare landscapes for winter weather
Published: Saturday, September 29, 2012 at 6:01 a.m.
Last Modified: Thursday, September 27, 2012 at 11:48 a.m.
Did you know last winter was a La Niña winter? Moreover, did you know the National Weather Service projects the winter of 2012-13 will be more of the same?
La Niña is a term to describe weather patterns resulting from the combined effects of cooler than normal water temperatures in the Pacific Ocean and the flow pattern of the jet stream across the country. During La Niña winters, conditions for Florida are projected to be warm and dry.
At first blush, I doubted the accuracy of this information. Warm I can believe; I remember that last winter was warmer than usual because there were a few, short cold snaps. We still had some cold weather; the effects just weren't as telling.
One reason I remember this is because the sweet corn in my garden last spring was an inch tall in about five days — much quicker than normal. I attributed this to the warm winter — the soil had never really cooled down. The difficulty I have buying that last winter was a La Niña is the dry part — it seems like it has been a very wet year.
Already in late September, we have had almost 58 inches of rain — 6 inches more than our total annual average. But in checking rainfall for last December through March, the rain numbers were indeed down. A 10-year average for December through March is 12.93 inches. From December 2011 through March 2012, our total was only 5.42 inches — well below the norm.
Because weather occurs in patterns, it is possible to look ahead with some accuracy. If the National Weather Service's projections are correct, this is good news for our winter heating bills and a warning to keep an eye on moisture conditions in turf and landscapes again this winter. During the summer, most of us have developed complacency when it comes to watering lawns and landscapes; it simply hasn't been needed since about mid-May, when we moved from a dry to a wet pattern.
Tropical Storm Beryl got us off to a good start on Memorial Day, dropping about 4.5 inches of rain followed a month later by 11.5 inches from Tropical Storm Debby. Rains have continued on a regular basis during the summer.
With this history in mind, the end of September should trigger some things to be done in landscapes in preparation for dryer and cooler weather.
First, Sept. 30 spells the end for pruning. Any shrubs and hedges should receive a final cut, if needed, to carry them through until mid-March. No pruning should be done after Oct. 1 because new growth is very tender and will be damaged by cold weather. For this same reason, no fertilizer should be applied after the first of October. Check landscape plants this weekend, and only if leaves indicate deficiency, apply a light fertilizer. A 1-0-1 ratio of NPK as a slow-release formulation should be employed.
This weekend also is a good time to check and adjust irrigation systems. Although these probably won't be needed yet, depending on how our October rainfall holds up, it is best to adjust them while temperatures are still warm. Put on your bathing suit and run each zone of your system. Adjust coverage so sprinklers do not hit the house, driveway or the street. Remember, plants will be moving into dormancy, so established landscape plantings probably won't need any supplemental irrigation until the warm days of spring arrive. Depending on rainfall, St. Augustine and Zoysia turf will need one and one-half inch of water every 10 to 14 days during fall and winter, while bahia and centipede lawns will need nothing at all. While the Weather Service isn't clairvoyant, based on past patterns, there probably is a good chance the coming winter will be warmer and dryer than normal, particularly if the La Niña pattern holds. Plan accordingly as you prepare your turf and landscape plants for the fall and winter season. Monitor weather carefully to determine if and when irrigation is needed.
David Holmes is Marion County extension director. Contact him at david.holmes@ marioncountyfl.org.
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