Cold Temperatures Forecasted to Impact Ohio

Managing Fruit Trees and Horticultural Plants During Prolonged Exposure to Subfreezing Temperatures

Having a few 80-degree days in April was a nice relief from winter like temperatures and renewed our hope for summer to arrive as quickly as it can. That kind of weather encouraged rapid progression of our landscape plants, fruit trees and other plant species, which has given us a spectacular show of spring blooms and flowers. The plants responded to the above average number of growing degree days that they accumulated and began their flowering, budding, pushing shoot growth, and beginning progress through developmental stages and reproductive processes. The flowers and buds are the most important part of the plant when we consider fruit production. They are also the most delicate and vulnerable part of the plant. Now we are faced with several nights of forecasted lows in the 20’s. This article may seem familiar, and it is because we had a very similar set up in spring of 2021.

Frost advisories in blue and hazardous weather outlooks in beige, all relating to freezing temperatures. Photo from the Cleveland National Weather Service. 

Regarding the cold temperatures: do what you can to protect your plants tonight. We are under a Frost Advisory for tonight, April 26th. Temperatures will be at or below freezing for roughly 8-9 hours for the next few nights. This is all very concerning due to the cold temperatures following multiple days of abundant heat. Wednesday night and Thursday night low temperatures look to be very concerning. The forecasted lows are 26 and 29, respectively. The clear skies on both nights will provide ample opportunity for extended periods below freezing. Being in the 20’s for 6-8 hours would result in a killing freeze. Tomorrow night is when growers should take more extreme measures to try to protect their trees and plants.
These kinds of weather events can have major implications on Ohio’s agricultural and horticultural crops.
So, what can be done to protect your plants? The challenge here is that our forecasted lows are between 26 – 29 degrees F, with almost 12 hours forecasted to be below freezing and 6-8 hours forecasted to be in the 20’s. This is not just a light frost, but rather a hard freeze. There are a few steps that you can take to try to protect the plants, and some of these steps can be better utilized on a small scale, while others are better utilized on a larger scale.
On a smaller scale, simple actions like covering the plants with a sheet or some kind of fabric can help insulate them. This helps trap some of the warmer air from the ground around the plant and keeps the plant from being directly exposed to the colder air. It may also be of interest to protect the crown of the plant. This freeze may be severe enough to damage the foliage, but you can take steps to protect the crown and the roots by mulching with straw, leaves or wood mulch around the plant to keep the warmer air from the ground around these vital parts of the plant to keep it alive. Basically, anything that you can do to insulate the plant, conserve the heat in the ground, and shield it from the cold air, will be beneficial to the plant and give it a better shot at making it through the night.
Adding a strand of Christmas lights (not LED) under the sheets covering your plants can help add a little extra heat to keep the ambient temperature a little warmer. Make sure that the lights are not touching the covering material and keep the covering material off of the plants. If the covering material is sitting directly on the foliage, that is defeating the purpose of having it there in the first place. Use stakes to keep the sheets or other covering materials just above the foliage. This will prevent the cold temperatures from being conducted onto the plants.
Watering the soil can also keep the immediate area around the plant a few degrees warmer. A wet soil is going to hold heat better than a dry soil. Even a few degrees can make a big difference. With single plants or with small enough shrubs or tree seedlings, an overturned bucket serves the save purpose as the sheets or coverings. Just remember, as soon as the sun comes up the next morning, you will want to remove whatever coverings you have to allow the plant to be exposed to the sunlight and begin to warm back up.
On a larger scale, orchard growers and those with small fruit have big challenges. They are dealing with a lot of plants and trees over a big area. Some orchards use frost fans to try and protect the crop. Frost fans work by utilizing warmer/drier air from the ‘inversion’ layer to create air movement at the fruiting/flowering height in orchards on still cold nights—preventing damage to flowers, soft tissue, and fruit. Some orchards utilize water sprinkler systems to actually create a layer of ice on the trees. The key to using water is to continually use it to form clear ice. Clear ice means that an endothermic reaction is taking place and the warmth of the plant is being trapped inside it. If the ice starts to become cloudy, the plant is losing heat and damage can occur. Spraying water must continue the entire time the freeze event is taking place, and the sprays must keep going from before there is a freeze event that would damage the fruit until the ice is completely melted from the tree after the event. If the water stops spraying on the clear ice, it goes from being endothermic to exothermic, and the heat loss and ice will damage the fruit.
In some cases, burn barrels and smudge pots are placed around an orchard to add heat in the hopes of keeping the temperatures at, or above freezing. Unfortunately, it can take roughly 30-50 heaters per acre to effectively protect the trees. In some cases, if you are working with just a few trees, a strategically placed burn barrel can do the trick. Keep in mind that if you decide to use any type of heater you need to be extremely cautious using them.
Minimizing damage and losses requires knowledge of weather conditions and how to mitigate weather extremes. Just as important is having a knowledge of plant hardiness. Some plants will do just fine with this cold weather. Others may appear to be killed off but may regrow from the roots or the crown, even though the foliage appears dead. The important thing here is to not be over-reactive. Give the plants time to recover. Plants can be remarkably resilient. If you see signs of frost damage, do not prune off the affected parts or dig up the plant immediately. Wait until the weather warms up to see whether new leaves sprout. You may see healthy new growth at the base of the plant, at which point you can prune out the damaged parts.
Hoping for the best and doing nothing will not result in any positive outcomes, so take this opportunity to at least cover the plants that you can and give them a fighting chance to make it through the cold.

Attention Specialty Crop Growers!

Get Started Now On Your Ideas for the …


March 25, 2022

9:30 – 11:00 a.m. ESTYou have received an invitation to join this quality conversation about CFAES research and Extension support for Ohio Specialty Crops Partners. CFAES will:

  • Provide updates on our priorities, existing support for specialty crops, and actions we are taking related to research and education for specialty crops.
  • Explore emerging trends for specialty crops agriculture in the state.
  • Listen to the industry needs and how CFAES plays a role in the industry.

We’re anxious to get started in this conversation and want to give you time and opportunities to give us your thoughts. If you would like to, please go ahead and get started by answering a few questions for us at this link .Please plan to attend the virtual session even if you complete this form. We want you to have as many opportunities as possible to provide feedback and have your voice heard. Please send your thoughts back to us no later than March 23.  And don’t forget to register for the virtual session no later than March 24, 2022 at register me now!

Ohio Grape Grower Survey

Attention grape growers! Please consider participating in the Ohio Grape Grower Survey! Contact Dr. Jackson-Smith at or by phone at 330-202-3540 with any questions or to get involved.

The Ohio grape industry produces grapes for wine, juice, and table grape use. Over the last decade, the industry has grown rapidly in our state. Unfortunately, the USDA ceased conducting a regular Ohio grape census five years ago, making it difficult to track this growth or collect accurate information about the number of acres and production by grape variety. To fill this gap, the Ohio Grape Industries Committee has commissioned researchers at The Ohio State University to conduct an independent survey of all Ohio grape growers.

Dr. Douglas Jackson-Smith, a professor in the College of Food, Agricultural, and Environmental Sciences at Ohio State, is leading the survey effort which is designed to reach all Ohio producers who grew wine, juice, or table grapes in 2021. Beginning the third week of January, researchers will send the survey to a comprehensive list of grape growers in the state, with an opportunity to respond through the mail or online.

The survey is voluntary and all responses will be treated as confidential. To get an accurate picture of the size and scope of the current Ohio grape industry, it will be critical to hear back from all producers. Aggregated results will be shared in a report that will be available to farmers, wineries, juice processors, and others to inform their decisions.


Bugging Out in the Fall

When people think of fall, most people think about the leaves changing colors, cooler temperatures, and all things pumpkin spice. When I think of fall, I think of all the bugs that make their presence known when temperatures and leaves start to drop. After a summer of warding off the threats of biting and stinging insects, you might let your guard down during this time of year, however, if you aren’t a fan of having 6 legged visitors in your house, it would be a good idea to do what you can to prevent some of the following common invaders from finding their way into your home.

One of the most prevalent home invading insects, and one that you may have already had problems with this year is stink bugs, specifically the brown marmorated stink bug. Per their name, it is best not to go after these with the fly swatter when spotted due to the unfriendly aroma that is released when threatened or crushed. As temperatures drop, the stink bugs begin to look for shelter indoors and seemingly are able to find even the smallest entry point into the home and make their way through the house via ducts, crawl spaces and other openings.

Another bug, which is sometimes confused for the stink bug is the Western conifer seed bug (WCSB). The Western Conifer seed bug is in a family of true bugs known as the “leaf-footed bugs”. The WCSB is a larger insect than the stink bug, overall lighter in color, with a longer body and enlarged femora on their hind legs. These bugs, as well as stink bugs, can often be heard before they are seen. Both of these insects produce a loud buzzing noise when they are in flight, and are not necessarily the most graceful at landing, when often the buzzing cuts off with an abrupt thud as they glance off of a window or lamp shade.

An additional true bug species that is commonly found in the fall hanging out on the exterior of homes and buildings is the boxelder bug. This species is found commonly on or around boxelder, ash, and maple trees. The appearance of the insect is mostly black or dark brown, with red “veins” appearing on the wings and abdomen, often forming a red “V” on the back of the insect. Throughout the summer, you may occasionally find them in your yard and garden, but once the season changes, they begin to seek for a place to over winter and may cluster on homes, warming in the sun and seeking a point of entry. Should a few find their way in, they are fairly quite in the house, mostly keeping to themselves behind walls and siding.

The multicolored Asian lady beetle is another common fall invader and may be the most annoying of them all. They can bite (more of a pinch), have a putrid smell and stains if crushed or threatened and are always active and in the way, unlike the boxelder bug. Adults vary in color from bright orange to a dull yellow or pale color, and they may have full dark spots, some spots, or no spots. These beetles are not the same as our native lady beetle species and are not a protected species.

There are several other insects like cluster flies, grain beetles, Indian meal moths, and other creatures like centipedes and silverfish that can be found in and around homes and buildings in the fall and winter. The most important step in managing these pests from entering the home is prevention.

All it takes to allow for these bugs, beetles, and other pests to get in is a small crack or crevice under a window, along a roofline, or behind the siding. A common point of entry in newer homes is via loose vinyl panels used for siding and loose soffit panels. When insects enter via the soffits, it is very easy for them to find their way into the attic, progressively finding their way through the wall cavities and eventually making their way into open living spaces. The drawback with vinyl panels is that they are hung with some spaces to account for expansion in the heat, however, this creates a challenge when attempting to prevent bugs from invading in the fall. Where you are able, make sure that cracks and holes on the exterior are sealed. While there are some cases where insecticide applications are warranted and effective, they can be costly and, in most cases, will not completely control the insects.

The other challenge in managing insects in the fall around your home is that first thing in the fall, while temperatures are still dropping and before we start in on really heating the house, the insects will be relatively inactive. It really isn’t until we turn the thermostat up and the furnace kicks on that we see major activity from the insects. Once the heat turns on, the insects may perceive this falsely as springtime and become active and are in search of food and water. Due to this, it is best to keep all food sealed, remove garbage, and prevent excess moisture, all in an effort to remove potential food and water sources.

Using a vacuum to remove insects can be an option, however, keep in mind that many of these bugs and beetles can produce a nasty smell and if you use the vacuum, either empty it quickly after use, or have one dedicated to insect removal.

Try as we might to keep the insects out, seemingly there will always be a few who find their way in. The positive thing about these insects is that none of them are a concern with regards to potential for structural damage to the home. Most of them do not bite, do not cause damage to structural or cosmetic features in the home and do not lay eggs or reproduce while inside. Regardless of the harmlessness of many of these pests, it is still an annoyance to share a living space with them, and gives us another household chore to deal with, year in and year out.