Q&A- Seth Nagy
There were some excellent questions that came into the Caldwell Extension Center this week, and I’d like to share two of them with you. I hope you find these questions and their answers helpful. If you have a specific question not answered here, please contact the Caldwell Extension Center directly.
Q: There is a hornet nest in my backyard. Can I remove the nest without fear of being stung?
A: After first frost, typically around October 15th, hornet nests can be safely removed. Hornet nests are not reused the following year.
In fact, unlike honeybees, only queen hornets survive through the winter. The queens do not over winter in the nest. They will spend the winter under tree bark, leaf litter, weedy areas, or some other inconspicuous location.
In the spring, baldfaced hornet queens will emerge from their wintering location to begin nest building. Once the nest is started the queen will lay eggs. The eggs will hatch and become workers helping the queen build the nest and establish the colony. The colony will peak in size sometime between July and August.
During September, the colony prepares for winter by producing queens and drones for the next year. The queens are fertilized by the male drones. The drones die and the fertilized queens seek shelter for the winter. In the spring, the cycle starts over when the new queen starts the process all over again.
To use a hornet nest for decoration, collect the nest in late October or November. Shake the nest to remove any debris. Then put the nest in a bag and place in the freezer for two days. This kills any insects such as earwigs that may occupy the nest. Nests disintegrate during the winter when exposed cold-wet conditions so collect the nest as soon as the hornets leave.
Q: Is it okay to use salt on my sidewalk to melt snow?
A: Typical ice melt products are chloride-based salts (calcium chloride, magnesium chloride, potassium chloride, or sodium chloride). Although it is important to treat sidewalks for safety reasons, it is important to understand potential environmental effects.
The chloride-based salts are relatively environmentally friendly products, but like all things, the dose makes the poison. Rock salt, which is a mixture of calcium chloride, magnesium chloride, potassium chloride, or sodium chloride, works well melting ice. However, too much can damage or burn plants in the landscape and be a pollutant to surface water. Normally two or three light salt applications are no cause for concern. Rain leaches the salts down through the soil profile. Although small dose of salt are not a problem to the environment and plants in the landscape, excessive salt applications can cause plant problems.
Salt damage to landscape plants shows the same symptoms as over-fertilization. Leaf margins and tips will turn brown. This browning is typically called “burn”. Extreme salt damage is evident within a few days or weeks. However, slight salt damage may not show up until mid-spring or early summer.
For this reason, be careful about over applying de-icing salt. Ideally, it is best to keep salt away from trees and shrubs. However, if too much salt has been applied on a surface that drains to a landscape planting, irrigate (water) the site to leach the salt out of the root zone of the plants.
Salt damage can also be avoided by utilizing salt substitutes. The Cadillac of ice melt products is calcium magnesium acetate (CMA). This material is one of the safest ice melt products for cars, vegetation, sidewalks, etc. Calcium magnesium acetate is biodegradable and its ice melt properties are comparable to most standard salt formulations. The main limiting factor for CMA is cost. This products typically is priced at twenty times the cost of rock salt. However, if small areas are being treated, it will not be cost prohibitive.
Fertilizer, such as 10-10-10, can also be used to melt ice. The main concern with using fertilizer as an ice melt is its ability to contaminate water. If your sidewalk and driveway drain into a the lawn or other vegetative area, it may be fine to use fertilizer as ice melt. However, nutrient pollution is a potential for surface waters and groundwater.
Whatever ice melt product you choose to use, apply it before the ice forms. This is more effective than waiting until ice has accumulated. Applying ice melt before the ice is a technique the NC Department of Transportation has been using successfully for several years and it works just as well for homeowners too.
Besides salt, CMA, and fertilizer, sand can also be used to reduce the slip and fall potential of wintery weather. Of course sand does not melt ice, but it does provide improved traction and it can be easily swept off when the sidewalk when dry.
Solar power is another option for melting ice. This is probably my favorite way to take care of ice on a seldom used sidewalk. Patience is key when solar power is being used. Now it may take longer than the other options, but in the end it will work just as well.
If you have horticulture or agricultural questions, please contact the Caldwell Extension Center at 828-757-1290 or visit us anytime online at https://caldwell.ces.ncsu.edu.