By Bob Parrish
Plants, like people, get confused sometimes. Especially, like when the weather is topsy-turvy. One day it’s 75?F ± and the next day it’s 25?F.
Plants have built in mechanics to protect themselves. A lot of times they get overwhelmed by several days of warm weather and then the weather goes sour. All the new growth gets burned from the cold that was produced during the warm weather.
What’s a person to do when they get the gardening bug and want to have a nice looking yard by Easter?
When we have a wet winter, it’s not as big a problem because plants cell’s store water between their cell membranes and cushions the plant cells so they can expand and contract with the temperature fluctuation. When we have a dry winter, the exact opposite occurs. Plant cells dry out too much and they shrink to the point they can’t take up water and they die. Then we have to deal with sunscald, especially with thin-barked trees and shrubs. This occurs when the plant juices start flowing from the top down to the roots and vice-versa. When you go from a warm period and the temperature drops drastically at night and the sun pops up bright and shiny and heats up the trunk quickly and does not allow the bark to gradually thaw out, the plant cells burst and the bark splits creating a wound that some plants have a hard time healing.
The next time an insect such as a Bore comes by he sees this opening and here we have another problem to deal with. As many insects feed they secrete fluids that allow diseases to start growing on the secretions.
Okay! Now you’re pondering what to do to protect your investment in your landscape without breaking into your last piggy bank. Some basic things a person can do to prevent winter and early insect damage are these simple steps that begin in the fall months preceding the winter.
1. To help promote healthy plants always do a fall feeding program using a slow-release fertilizer in late September or by mid October.
These types of fertilizers are temperature sensitive and only release when soil temperature are 65?-70?F or higher. When the temperature drops below this range these fertilizers shut down and do not release until warm weather active the particles again. Water has to be present for the plant to take up nutrients so you may need to water during a dry period in the fall or winter even though it’s cold.
Cold weather dries out plants as much as hot weather. Check your ph in case you need to add lime to correct the acidity of the soil. A ph is a measure of the acidity of your soil and determines how the plant’s roots take up the nutrients from your fertilizer applications. Your local county agent can supply you with materials to do this test and in most cases this is a free service. Now you probably are wondering why you should do these things when a plant is not actively growing. Plants need nutrients in the winter so they can store carbohydrates in the roots or the food they need to start growing again in the spring. A plant starved during the winter has a hard time to fend off bugs and disease when they try to start growing in the spring.
2. Pruning in the winter months is also important, so you can remove dead or unwanted plant growth while the plant is dormant. This will help deter insects if you allow the plants to start juicing up and create juicy wounds that bugs like. It allows the plant to heal itself over a period of time when it’s not actively growing.
3. A fresh layer of mulch in the fall helps prevent roots from drying out at the surface when we get those dry winter winds. It conserves moisture in the ground and helps cut down the amount of watering you do and prevents germination of winter weeds and early spring weeds. It also helps the roots to stay a little warmer so they can continue actively supporting the plant.
4. Now, how about those pesky insects that seem to show up uninvited when those brief warm periods occur. Again we start in the fall. An application or two of insecticidal soaps or oils in the fall can reduce the number of insects that over winter on shrubs or trees. Drenching the soil with insecticide around the shrub or tree base will help get those bugs that over winter in the litter or mulch around your shrubs. Usually these insecticides applications work best when applied above 40?F and no higher than 80?F when you do it later in the spring. When spring temperatures are above 40?F for a few days, insecticides can be applied to help get the bugs that were missed in the fall.
Again, your county agent can help identify bugs and any disease that may occur early and make suggestions to treat the problem with the right chemical.
5. What about sunscald? When planting young trees and they are in a wide open space, you may need to wrap tree trunks with something as simple as newspaper or something that will breath and not trap heat behind the barrier and between the tree trunk. This will prevent the tree from warming up too fast and cause bark split.
Shrubs that form buds early can be protected by breathable materials such as sheets. Plastic sheets can be used but if not removed by the time the sun gets up the plastic will intensify the ultraviolet rays and scorch the blooms and any new tender growth. You can even spray a thin coat of water on the shrub and form a thin layer of ice to prevent damage however the ice needs to be washed off before the sun gets up to prevent rapid heat up. Believe it or not ice give off heat as it melts.
Well, I hope there are some ideas here that can answer some basic questions you may have about how to prevent winter damage, nutritional problems and insect problems that always pop up when you get that gardening urge. Are we there yet? We’ll have to ask Mother Nature because only she knows the answer. Oh Yeah! We do live in North Carolina where the weather can change in less that an hour, but its home. Take care and have a wonderful spring.
Your Friend at Green Biz Nursery,
Mr. Bob