By: Eddie Ayers, County Extension Agent
Late summer/early fall is an excellent time for you to survey or map the weeds in your pastures, hay
fields, orchards, and lawns, but it’s not the best time to spray. The majority of weeds growing in early fall
are usually summer annuals and summer perennials. Many people want to control summer annual weeds
that are present, but treatments now are usually unsuccessful. Your time would be better spent mapping
out your control strategy for next year.
Herbicides are usually more effective on weeds that are young and actively growing. The large size of
summer weeds makes them easy to identify for mapping out heavy infestations or "hot spots." Knowing
which weeds might be causing a problem and their location in the field allows you to develop a control
strategy for next year’s summer weeds.
For example, with fall here, many pastures are turning a brilliant shade of yellow. This is usually from a
problem weed called bitter sneezeweed but it could also be ragweed. Late summer or fall is not the
preferred time to control bitter sneezeweed or ragweed. Instead, controlling them in the seedling stage of
growth is cheaper and more effective but this is determined by scouting your lawn or pasture now.
Remember that proper identification is critical. A heavy frost is probably the best control for summer
annuals in the fall, but if you want to control them from spring thru summer, make notes now.
The key to low cost weed control is to match the most cost effective herbicide to the weed problem and
then apply the herbicide at the correct time of the year. The correct identification is needed so that you
can apply the correct herbicide. Keep in mind that there are two basic categories of herbicides. The two
categories are pre-emergence and post-emergence.
A pre-emergent herbicide is applied before the weed appears. This also means before the seed
germinates. If you plan to use a pre-emergent herbicide, it is extremely important to know what weeds
you had this year because chances are those are the weeds you will have next year. You can however
apply a pre-emergent now for winter weeds. One tool to keep in mind is the UGA weather network found
at www.georgiaweather.net which will give you soil temperatures so you can determine if it’s warm
enough for a seed to germinate. In the spring seeds usually germinate when the soil temperature is around
A post-emergent herbicide works after the weed has germinated, but you need to apply it early in the
growth cycle as the weed is easier to kill when it is small. There are exceptions, but in general, late May
and early June are the preferred times to control summer annuals. Most weeds will be in the seedling to
early vegetative growth stage at this time and will be more susceptible to control by the herbicide. For
winter weeds November is a good time to apply a post-emergent.
For more information, contact me in the Gilmer County UGA Extension office.
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Well Water Testing
By: Eddie Ayers, County Extension Agent
For the most part, north Georgia did not see extreme flooding as a result of hurricane Irma as did other areas of the state, but it does bring to mind the importance of well safety. Wells that were overtopped by flood waters need to be flushed and tested for bacteria because of the potential danger of contaminants being washed into the well. UGA Extension Water Resource Management and Policy Specialist Gary Hawkins recommends pumping and flushing a minimum of 2 or 3 times the well volume to clear the system. This water should be discarded from an outside faucet and not from an inside faucet to bypass the home’s septic tank. After pumping the water, the well should be shock chlorinated then the well should be flushed again until there is no smell of chlorine bleach and, like before, the flushing step should be done through an outdoor faucet to bypass the septic system. This highly chlorinated water, if discharged to the septic tank, could cause problems with the bacterial colonies in the septic tank.
After the well is shock-chlorinated, flushed and the chlorine smell is gone (about two weeks), the well water should be tested for bacteria. Families can get their well water tested using their local county UGA Extension office. Until the test for bacteria comes back, Hawkins strongly suggests that water for cooking or drinking be boiled before consumption. If the well contains bacteria the report will explain how to treat the well.
To calculate the volume of water that should be pumped from a well, use the following calculation. Most of the well casings in this area are 6 inches so the factor for that size is 1.47. That means that there are 1.47 gallons of water for every foot in depth. Multiply the depth of water in the well by this factor to determine how much water is in the well. If your casing is not 6 inches, contact me in the Gilmer County UGA Extension office and we can get the right factor.
There are several methods to determine how much water you have flushed out, but the one that I use is to calculate how long it takes to fill a 5 gallon bucket. Divide that time by 5 to get the output per minute. Using this figure you can determine how many minutes you need to run the water to flush the number of gallons of water that was determined in the previous calculation. A couple of methods can be used to determine the depth of water in a well. If you can see the water in the well, lower a heavy object tied to a string down the well and measure the length of the string until you see the object touch the water. In a deep well, lower a heavy object like above until you hear the object hit the water and measure the length of string. If you cannot see the object hit the water, another way (but less accurate) is to drop a small stone into the well and count or time the seconds it takes for the stone to hit the water (you will have to listen closely for this.) Multiply the number of seconds by 32.2 and that will let you know how far the water is below the surface. Knowing the depth of the well and the depth from surface, subtract the two to get the height of the water column for calculating the volume of water in the well.
An example of this calculation is if you have a well that is 300 feet deep and the water level is 25 feet from the surface, subtracting 25 from 300 equals 275 which means you have 275 feet of water in the well. Multiply 275 by 1.47 to get the gallons in the well. That figure is 404.25 gallons. Using a factor of 3 pints per 100 gallons, you would need to apply a little over 12 pints of chlorine bleach in the well.
If you have any questions about this process or for more information on well water testing, contact me at the Gilmer County UGA Extension office.
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Fall Shrub Care
By: Eddie Ayers, County Extension Agent
It’s that time of year when we must start looking ahead and planning for the upcoming winter. The shrubs in our landscape will benefit greatly from a little bit of tender loving care this fall. Shrubs going into the winter that are hungry (lacking fertilizer) have a much greater chance of winter injury and poor growth the following spring if we don’t give them some attention now.
Azaleas which are rapidly turning yellow or the older leaves are yellowing and falling off indicate a lack of nitrogen going into winter. The leaves on the red flowered selections often turn reddish-brown before the leaves fall off. Late summer and early fall is the ideal time to prevent this yellowing from occurring. If you’re seeing these symptoms now, it’s not too late to take corrective measures. Taking a soil sample and following the recommendations is best, but if you feel you don’t have time to take a soil test, apply a balanced slow release fertilizer that contains a small amount of nitrogen.
A little light pruning in the fall can also do miracles in shaping up shrubs for the winter season. Evergreen hollies and magnolias can be saved until you want to cut foliage for winter decorations. Light pruning in the fall is used to remove long branches and any dead, damaged or diseased branches. Remove those branches that interfere with the driveway, mowing the lawn or the walkway. The pruning cuts should be made back into the interior of the plant at a point where the branch is attached to a larger stem. Sheering evergreens in fall is not recommended since they will produce another flush of growth that is too tender to survive the winter. Too much pruning in the fall makes plants much more susceptible to winter damage and death. Also, pruning in the fall will remove flowers from next year’s spring blooming shrubs so fall pruning should be done lightly and only to shape the plants and remove dead and diseased limbs.
If you have time to take a soil sample, its $9 a bag and one sample covers about 15 acres. We have the bags and testing instructions in the office but generally, just dig down about 3 or 4 inches in 6 different areas, mix it altogether in a small bucket, pour it in a pint size plastic baggie and bring it by the office. We can transfer it to the soil sample bag and send it to the soil, plant and water lab for testing at the University of Georgia. We collect soil samples all week and send them to Athens on Friday mornings. It takes about a week to get the results and recommendations.
For more information about fall pruning and soil testing, contact me at the Gilmer County UGA Extension office.
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