A number of years ago I came across a bottle of anti-transpirant and I wondered what the material was used for myself. This information should be referred to this time of year on a regular basis. So, I’ll attempt to answer my reader’s question about this material here.
Anti-transpirants or anti-desiccants are compounds that are applied to the leaves of plants to reduce transpiration for the most part. They consist of a colorless film on the leaf surface which allows diffusion of gases but not of water vapor. Examples of the anti-transpirant include silicone oil and waxes. This compound, anti-transpirant, is also the material you might see being sprayed on Christmas trees when they are being harvested in the fields, or on plants that are being harvested such as flowers that are going to a florist.
Each year during the winter when the temperatures are cold for an extended period of time and the soil freezes below the roots, you will see the evergreen, like rhododendrons and azalea that are on all year, are leaves that look normal as you may see them during any time of the year. When the temperatures rise after an extended period during a cold winter, you begin to notice that the leaves curl and look a little like a stick. What is going on is that the leaf is trying to transpire and bring the water up from its roots and leave through the pores or stomas. Only problem is that when the ground is frozen the plant can’t perform as it normally would and that is the azalea’s normal reaction to the transpiration process.
The rhododendrons and azaleas that have leaves on during the winter will have this stick appearance, which is considered a normal reaction. This stick appearance reaction can be an extra stress on a plant that you’ve just planted and putting this compound on the surface of the leaves you can give your plant an extra chance at survival. Seriously, you would only want to apply this material before you would begin to experience freezing temperatures. Hopefully, we have a number of weeks left before we experience freezing soils.
We want to continue to allow the carbon dioxide uptake of the rhododendron or azalea, which is a part of the normal functioning of the plant and the water vapor is retained in the plant. Therefore, gases can exit the leaf and the water stays. All that I could recommend for your azalea is that if your plant does not lose any of its leaves during the winter, then it makes a lot of sense to get the anti-transpirant or anti-desiccant.
My normal recommendation for watering any plant is that you should have at least one inch of moist soil down from the surface of the ground near the plant. With my busy life I don’t always do the jobs that I need to get done with this topic. If you can put your finger into the soil and the soil is moist one inch down all around under the drip line of the tree you should be set for a plant that has just been in the ground for five years. This process should be done about once a week during the week at least. For a new evergreen planted within five years the process is a little different.
You should stretch out that perimeter another three to five feet and beyond and the moisture should go down 12 inches. This should be done a minimum of three times during the month as a drought would continue. I’ve also been taught that if you water your azalea or rhododendron well before the ground freezes your plants will also have an improved chance to survive. If you are experiencing a busy time during your life, like one of my clients in Columbus, you can always irrigate the beds you need to water and set your watering chores to come on automatically.
The temperatures you need to apply an anti-desiccant is between 40 and 50 Fahrenheit and dry. You don’t want to have any rain in the forecast for a few days. Our evergreens need to be completely dry when applied and two days after. December is the noted month for applying an anti-desiccant. Trees need to be completely dormant before spraying. When a tree goes dormant their water has been moving down to the roots from the leaves. If you have had a few good hard freezes, your evergreen will be ready for the treatment. Water can become trapped in the leaves, which can burst plant cells as the leaves freeze in colder weather. Apply the anti-desiccant to both the top and bottom of the leaves. You will find stomata or pores on both the top and bottom of the leaves and be thorough. Mostly just follow the directions.
On my stroll through the garden this week I have my normal winter color. I’m also enjoying the berries on my snowberry and tiny beautyberries on my beautyberry bushes. Hope you enjoy your stroll through your garden. If you have some questions about your garden please don’t hesitate in e-mailing me at email@example.com or through my links at ohiohealthyfoodcooperative.org you can leave comments at my blogs on the columns that you like to read. I shall do my best in helping you through the problem.
Eric Larson of Jeromesville is a veteran landscaper and gardening enthusiast and a founding board member of the Ohio Chapter of Association of Professional Landscape Designers. He encourages your gardening questions by sending an email to firstname.lastname@example.org.
This article originally appeared on Mansfield News Journal: A Stroll through the Garden: Anti-transpirants can help plants