COUNTY AG NEWS
Prevent salt injury to your plants this winter
by Alana Voss, Juneau and Sauk Counties Agriculture Educator
The first day of winter is on Friday, Dec. 21 and we all know what comes with winter… snow and ice. We all do what we can to battle the icy sidewalks and roads, but have you ever stopped to think about how the ice melt (salt) affects your plants and the plants along the road ways? You can usually see the effects of the salt injury to plants later on in the growing season along roads, driveways, and sidewalks. The salt can affect the plants in one of two ways: through salt spray, which is evident in early spring when the weather starts to warm up, or due to salt in the soil. This last option might not be noticed until after a few years of this repeated damage.
The salt spray damage can be seen through seeing buds on and twigs dying off, and plants having delayed growth and thinning of their branches, potentially creating misshapen plants. This also causes discoloration in the plants on the leaves and the needles, and only the new growth would show green. These effects are caused by the fact the salt spray causes dehydration through the plant tissue and makes it difficult for the plant to survive the winter.
The other issue is having salt in the soil, which can upset the balance of nutrients in the soil, causing the plant to suffer. The reason for this is soil particles hold the water more tightly and allow the plant to take up less water. This is a slower paced issued and may not be caught soon enough to correct the issue. You will see plants stunted with leaf burns and may change colors prematurely and have an early leaf drop.
When trying to diagnosis salt injury, please remember that there are other symptoms that may result from other causes. Some of these examples include: construction injury, air pollution, or improper planting, just to name a few. However, there are certain patterns that can help in determining if it is truly salt injury affecting your plants. Two options you can utilize to help determine if you have salt injury to your plants is taking a tissue test during mid-summer or doing a soil sample in early spring before the salt can move lower than the soil testing depth. You can learn more on these tests and salt injury by contacting your local UW-Extension office.
There are things you can do on your part to help reduce the chances of salt injury to your plants. First and foremost, would be to reduce the amount of salt being used during the winter months. One way to reduce your usage of salt is to mix the salt with an abrasive material, such as sand or ashes. You can also wait to apply the deicer until after you have finished shoveling or plowing. In addition, you can wait until the end of a snow storm to apply the deicer, which can help to reduce the amount of salt being used; however, it is sometimes be better to apply a small amount of ice melt early on to decrease the chances of the ice freezing to the pavement.
Finally, you can take some cultural control options to help in preventing salt injury to your plants. For your existing plants you can create barriers around your plants to help reduce exposure to salt spray by utilizing things such as burlap, snow fence, or plywood. Furthermore, avoid shoveling piles of salt covered snow on the root zones of the sensitive plants. Then in the early spring, you can flush out the highly salted areas with water and/or create a new drainage path for the salty runoff.
If you plan to do new plantings, there are a few species of plants that are salt tolerant you could look at planting in the spaces that maybe affected. Or you could plant new plantings 60 feet away from highways and 30 feet away from city streets to reduce their exposure to salt.
You can learn more about salt injury and salt tolerant plants by connecting with your local Agriculture Educator at your County’s UW-Extension office.