Watching and Working
Hemlock Woolly Adelgid
Have you seen small white cottony balls on hemlock trees? If you have then that means those trees are infested with Hemlock woolly adelgid (HWA). Let’s look at why it’s important to preserve hemlocks, what is the pest that is killing them, and what you can do to save them. We are getting to the time of year when they really start to come out.
Hemlocks are a native species that ranges from Maine to Northern Alabama. They are a keystone species that provides habitat for about 120 species of vertebrates and over 90 species of birds. Hemlocks are unique in their ability to thrive in shade. This attribute makes them common in ravines and along rivers and streams. Their proximity to streams and rivers means that they are crucial in reducing erosion and watershed protection. Hemlocks can be identified by their needles. They have short flat needles with two distinctive pale white stripes on the underside. The needles are wider at the base and taper to a rounded tip, unlike firs which have parallel sides the whole way down.
HWA is a very small insect. The white cottony sacks on the hemlock trees are egg sacks of HWA. They are an invasive species from Asia that doesn’t have a natural predator here. HWA feeds on the sap inside of hemlock trees. The HWA can be spread by wind, birds, deer, or humans. Once a tree has become infected it will die within four to 10 years. Therefore, it is important to treat trees as soon as possible after finding that they have been infected.
It is important to treat your own trees with cultural and chemical controls. Cultural controls include keeping hemlocks well mulched and watered. Hemlock trees don’t have very deep roots and droughts can make them more susceptible to infection. Don’t place any bird feeders or deer feeders near your trees. Birds and deer can carry the eggs for long distances. If you are hiking in an area that has HWA wash your clothes afterward because you may be carrying eggs. Be careful to not over fertilize your trees as that could make them more enticing to HWA. Cultural controls may keep your trees healthy, but if they become infested chemical controls are the only option. Chemical controls involves treating your tree with either Imidacloprid or Dinotefuran, and is the most common and effective method of control. An imidacloprid treatment will last four or five years. However, it may take one year before it is effective. Dinotefuran will last for two years in the tree and will take about four to six weeks to take effect. The ideal way to apply either of these insecticides is by soil injection. Soil injection will mean quicker uptake by the plant and reduce the chance of off target drift. If the trees are near open water a trunk injection of insecticide is necessary, which will require a professional. Whenever applying a pesticide it is important to familiarize yourself with the label before using the product.
The Union County UGA Extension office has a soil injector that is available to be checked out. Checking it out requires a $250 dollar deposit that will be returned with the injector is brought back. You must provide your own insecticide.
Contact your local Extension Office or send me an email at Jacob.Williams@uga.edu if you have any questions about HWA.
Lime is a very important part of having healthy soil where we live. Knowing how much to apply and where to apply are very important considerations to effectively use lime. Let’s talk about what lime does, why you need it, how much to apply, and how to apply it.
There are a couple of different types of lime that you can purchase. Ag lime is a very common type. It is made up of calcium, carbon, and oxygen. Ag lime will do a very good job of raising the pH in your soil. Dolomitic lime also raises the pH level of soil, but it has magnesium in it as well. If your soil is deficient in magnesium, dolomitic lime is a good option to raise the soil pH, and to increase the amount of magnesium in your soil.
When you get to the bottom of it lime raises the pH in soil. If you recall from chemistry class, pH is basically a measure of the free hydrogen ions in a substance. In this case that substance is soil. pH is a scale that goes from 1 – 14. Numbers below 7 are acidic and numbers above 7 are basic. 7 is neutral. Our soil is going to be naturally acidic. I’ve seen soil reports with pH ranging from 4.5 – 5.5. Most plants like to have a pH of 6 – 6.5. The past couple of weeks I’ve been talking about fertilizers. pH is very important because it impacts how available the nutrients are to plants to be able to take them up. If the pH is low, then most plants won’t be able to grow because they can’t utilize the nutrients that are in the soil.
There’s no way to accurately know how much lime you need to add with doing a soil test first. A soil test will make a recommendation for how much lime you should add based on your pH. It is possible to add too much lime. If you add lime year after year with looking at a soil test as a guide you may end up over liming your land. This can lead to a pH that is too high. You can run into similar issues as with a pH that is too low. A high pH is not common around here unless you’ve over applied lime. In the western half of the country soils naturally have a high pH.
In small areas lime can be applied with a push spreader. You want the lime to make as much contact with the soil as possible, so it may take a few days to water it in. Lime does not dissolve very well in water so it may take a while for the lime to take full effect. Lime can be bought in powder form or pelletized. Both work well, but the pelletized may make less of a mess. There is also liquid lime. Liquid lime can be effective, but it will take more product because it has been diluted down. Larger areas such as a pasture may need a spreader truck to apply the lime evenly and efficiently.
If you have questions about lime contact your local Extension Office or send me an email at Jacob.Williams@uga.edu.
Radon is an invisible, odorless gas that causes lung cancer. Every 25 minutes someone dies from radon induced lung cancer, making it the second leading cause of lung cancer. During Radon Action Month this January, UGA experts are advising you to test your home for radon gas. I’d like to talk about what this dangerous gas is, how you can find out if you have it, and what you can do to reduce the radon in your house to a safe level.
When uranium, which occurs naturally in Georgia soil and rock, breaks down, it produces radon gas. Radon is a heavy gas which seeps into homes from the ground and concentrates in the lower levels of a house. Radon can be present in any home, regardless of the age or type of home. The U.S. Environmental Protection Agency (EPA) estimates that about 6.7% of homes nationwide have elevated levels of radon gas; however, in some counties the levels are higher. Homes in north Georgia can have high levels of radon. In Union County, between March 2003 and July 2017, about 46.5% of the homes tested had elevated levels of radon. In Towns County it was 33.1%. An elevated level of radon is anything at, or above, 4 picocuries per liter (pCi/L). Being exposed to a level of 4 pCi/L has similar health effects as smoking 8 cigarettes per day.
The only way to know if your home has a high level of radon is to test for radon. Radon test kits are available from several sources, including local retailers, the Extension Office, and by ordering online at www.UGAradon.org. Purchasing a kit from the Extension office costs $10.
If the radon level in your home is high, it is fixable. Installing a radon reduction (or radon mitigation) system will reduce high levels of indoor radon to acceptable levels. The system most commonly used is a vent pipe system, which includes a fan that pulls radon from beneath the house and vents it to the outside.
Just because your neighbor has had a negative radon test does not mean that your house isn’t affected. Also, if your neighbor has had a positive test it doesn’t mean that you have radon in your home. It is advisable to test your own home. Experts usually advise that you have your home tested regularly to make sure that radon levels are low.
Radon may also be found in drinking water. This is primarily a concern for individuals whose drinking water comes from private wells. In Georgia, wells drilled into granitic crystalline rock aquifers (pretty common for wells around here), are at risk of naturally occurring radon contamination. This is where the uranium that decays to radon can be found at higher levels. If you don’t know if there is radon in your well water, have the water tested. The UGA Agricultural and Environmental Services Laboratories in Athens tests water samples for the presence of radon. To get a water testing kit, contact your local Extension Office. Testing for radon in water costs $40. For more information on radon, visit www.ugaradon.org. Radon can be a serious concern in our area. It’s best to be tested to know if you have dangerous levels in your home.