Two myths that should go down with fall

Published 4:41 pm Friday, September 22, 2023

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When the days begin to get shorter and cooler, there are two very popular myths that I begin to hear.

  • It is time to prune all of my shrubs back for the winter
  • I need to winterize my lawn

Pruning

To begin with, pruning shrubs back this time of year is not a good idea. If we happen to have one of those cold winters like we used to, there is a very likely chance that this can severely damage or even kill the shrubs. In Northern climates, where it gets cold and stays cold throughout the winter, this can work. Here in Eastern NC however, we rarely ever get cold and stay cold. The saying “If you don’t like the weather, just wait 15 minutes and it will change,” applies to us. The pruning cuts, along with warm weather, causes a growth response in the shrubs. As soon as they begin growing and it turns cold again, this new growth will be killed resulting in stress to the plant. The new growth isn’t hardened off against the cold weather. If you just need to shape them up, that is fine but if you are doing a major pruning, it is best to wait until February.

Always make certain your tools are sharp and clean. Use a sharpening stone or file to sharpen your tools on a regular basis. Put a little lubricant on them to make sure they are working properly. To sterilize your tools in between cuts, use a 10% bleach solution or disinfectant spray. Be sure to clean your tools and oil them really well when you are finished because the solution used for sterilizing can cause them to rust before they are used again.

Begin pruning by looking for dead, diseased, or damaged wood. Prune these branches and limbs out first. Next, look for any branches or leaders that may be crossing one another, one of these will need to be pruned so other can survive. Lastly, look at the overall shape of the tree and make cuts to help the shape light penetration, and air movement through the tree. This lessens the instance of disease within the tree.

Clean up all your scraps and make sure that any leaves have been removed that may harbor diseases over the winter.

Plan to fertilize in March according to a fertilizer sample. Take your sample now to know what to fertilize with in the spring. Samples should be taken around the dripline of the tree; this is the average extent of where the leaves reach. Fertilizer and lime application should be concentrated in the area as well. Lime application can be made now so that the pH is corrected by spring.

Winterizing

There are major advertisement campaigns geared towards selling these products nationwide. To be honest, this is not bad advice, it’s just bad advice for your warm season grasses. See, warm season grasses do all of their growing in the summer and this is when they require fertilizer. In the fall, and even before fall, as the days get shorter, these grasses are already setting up for dormancy. Fertilizing now can disrupt dormancy, essentially telling the grass hey, summer isn’t over, it’s time to grow. Just like our shrubs and trees, if the grass is not hardened off for winter, it’s going to be severely damaged if not killed completely.

A good practiced is to not fertilize after July 15th on warm season grasses in our area. If you are trying to push an area of grass to fill-in, you can push that last fertilizer date out to August 15th but I would not make that a regular part of my fertilizing regime.

The only exception to this rule is potassium (K) only fertilizer. This type of fertilizer has been shown to promote root growth. Our grasses, even though dormant, continue to have root growth throughout the winter, so this is not a bad practice. It is also not necessary however, if you have used fertilizer throughout the season that contains a potassium component. This can result in issues with uptake of other nutrients such as Magnesium. Potassium can displace this nutrient causing deficiency symptoms such as chlorosis (yellow looking grass).

The best practice is to fertilize your lawn beginning in mid-May according to a soil sample recommendation. Soil samples are available at your local extension center and are sent to NCDA&CS for analysis. Once testing is complete, NCDA&CS will email a report, complete with recommendations for what to apply to your soil.

If you would like to know more about these or another myth, give your local extension center a call and ask to speak to the Horticulture Agent. In Beaufort, Hyde, Tyrrell, and Washington Counties, that’s me. Give me a call at 252/946-0111 to reach me at the Beaufort County Center.