Protecting Fruit Plants During Frost or Freeze

blueberry blossoms

Fully open rabbiteye blueberry blossoms are likely to be damaged if temperatures fall below 30 degrees. Image by Bill Cline, NCSU.

As a reminder of just how fickle Carolina springs can be, a freeze warning is in effect for much of central North Carolina tonight. Temperatures as low as 28 degrees are expected overnight in the region, with the potential for colder or milder actual lows dependent upon your location. Temperatures below 30 at this point in the season could damage the blossoms and nascent fruit of apples, pears, peaches, plums, blueberries and strawberries. The extent of damage, and what you can do to prevent it, will depend on how cold it actually gets.Fruit TreesFor most fruit trees, open blossoms and the phase just after petal shed are the most sensitive to frost or freeze damage. During this time, temperatures of 28 degrees are expected to kill 10% of blossoms. Losing 10% of their potential fruit load could actually be helpful to many fruit trees, which tend to set many more fruits than they can support. The danger comes when temperatures fall any lower – a dip down to 25 degrees could kill up to 90% of blossoms and severely limit this year’s crop.From a practical standpoint, there is little that can be done to protect fruit tree blossoms. Small trees could be covered with row cover or plastic but covers will need to completely envelop plants and extend fully down to the ground to provide protection.

Blueberries

Blueberries are just starting to bloom in our area, placing them at the most vulnerable stage for frost or freeze damage. Fully and partially open blossoms of rabbiteye blueberries can be damaged at 30 degrees, to the point they cannot be pollinated, and completely killed at 29. Temperatures of 30 degrees can damage small green fruit, resulting in misshapen and undersized berries.

If there are many blossoms on your blueberry bushes and the plants are not too tall, cover them later this evening to prevent loss of early fruits. The goal of covering plants with row cover, old blankets or plastic sheeting is to create a mini-greenhouse that traps in heat from the soil that would otherwise radiate out into the night air. To be effective, covers need to completely encase plants, extend fully to ground level, and be well secured. The good news for blueberry lovers is blueberry bushes don’t open all their blossoms at once. Even if you lose some flowers (and potential fruit) tonight, more flowers should open in the coming weeks.

 Strawberries

vegetable bed covered with row cover

Strawberry flowers can be damaged or killed at temperatures of 30 degrees or lower. Young green fruit are slightly hardier, withstanding 30 degrees but receiving damage at 28. Because they are lower to ground, strawberries are much easier to protect with covers than blueberries or fruit trees. Be sure to cover your strawberry plants tonight to save any open blossoms and young fruits. As with blueberries, strawberries flower over an extended period so even if you lose some fruit potential tonight you will still get blossoms and berry production in the weeks to come.

Closing Thoughts

Be sure to remove any covers tomorrow morning after temperatures rise above freezing. Fruits that survive tonight’s freeze are still not out of the woods. Overnight lows of 28 degrees are predicted for Saturday night as well. Other than fruit loss, a 28 degree freeze is not expected to cause any long term damage to fruit trees or berry bushes. The same cannot be said for frost sensitive vegetable plants such as tomatoes, peppers, basil, cucumbers and squash. If you have taken the risk of planting early, be sure to these plants are well protected overnight.

More tips on protecting vegetables and other plants during cold snaps are available here.

Visit the National Weather Service for the latest forecast details.

Visit this link to access resources for growing many types of fruits, including slides from the recent Extension Gardener class on growing fruits and berries.

Use Extension Search to find research based information from Cooperative Extension systems across the U.S.

Visit your local Cooperative Extension center to learn more about gardening and landscape care. Find your county Extension center or post your questions to be answered online via Extension’s ‘Ask an Expert’ widget.

Subscribe to the Chatham Gardener email list to receive timely updates on sustainable lawn, garden, and landscape care for the central NC Piedmont. To subscribe:

Written By

Photo of Charlotte GlenCharlotte GlenState Coordinator, NC Extension Master Gardener Program Chatham County, North Carolina

Posted on Apr 5, 2016
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This page can also be accessed from: go.ncsu.edu/readext?405787

Save the Date for Chatham County Spring Ag Fest!

Celebrating Chatham County Agriculture, Forestry, and Natural Resources 

This is a FREE event

Saturday, March 24, 2018

10:00 am – 2:00 pm
Chatham County Agriculture & Conference Center

1192 US 64 W Business
Pittsboro, NC 27312

 

Chatham County invites residents to join us for our first annual Spring Ag Fest at the Chatham County Agriculture & Conference Center (CCACC) on Saturday, March 24, from 10 am to 2 pm. This event evolved from our very successful CCACC Grand Opening Celebration in 2017. Over 1,500 people so enjoyed the exhibits and events that we decided to make it an annual event! Click here to view photos from the Grand Opening Celebration.

The Spring Ag Fest is a celebration of Chatham County’s agriculture, forestry, and natural resources. The event will offer something for everyone: livestock, exhibits, demonstrations, food trucks, and more.

We have some exciting events planned at the Livestock Arena:

  • 4-H livestock exhibition
  • Barrel racing demonstration
  • Dressage demonstration
  • Cutting horse demonstration
  • Sheep herding demonstration
  • NC Horse Council Parade of Breeds

Livestock including cattle, sheep, poultry, goats, horses, rabbits, and more will be on display for an up-close look. We will have FREE pony rides for kids!

Indoor and outdoor exhibitors and vendors will highlight local farms, farmers’ markets, sustainable agriculture, agricultural support and advocacy, agribusiness, beekeeping, livestock, forestry, green industry, wildlife, conservation, and much more. Visitors will get an up-close look at the Forest Service’s firefighting helicopter and meet Smokey Bear.

Several food trucks will offer tasty options for lunch.

The event is free and open to the public. Full details with a complete list of exhibitors and events will be released in February.

If you are interested in exhibiting around the theme of agriculture, forestry, or natural resources, email Debbie Roos for more information.

The CCACC houses the offices of Chatham County Cooperative Extension, Farm Service Agency, Natural Resources Conservation Service, Soil and Water Conservation, and the Forest Service.

The event facilities provide year-round meeting and workshop space for agriculture, horticulture, forestry, natural resources, family and consumer science, and youth programs. However, the CCACC is available for rental by organizations and individuals for all types of events, including conventions, trade shows, weddings, workshops and banquets. It is the largest flexible meeting space in the county.

The CCACC is one mile west of the traffic circle at 1192 US 64 W Business in Pittsboro.

 

 

 

Exhibitors inside the Conference Center Exhibit Hall.

Jennifer Howard of Buck Naked Farm was one of the outside exhibitors.

Extension Dairy Agent Marti Day brought her Jersey cow Milkshake with bull calf Frosty to exhibit.

NC Cooperative Extension Logo   Chatham County Center

Chatham County Logo

Farm Bureau logo

agcenterlogo
Celebrating Chatham County Agriculture, Forestry, and Natural Resources

Written By

Photo of Debbie RoosDebbie RoosExtension Agent, Agriculture – Sustainable / Organic Production Chatham County, North Carolina

Updated on Jan 19, 2018
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Helping Trees and Shrubs Recover From Snow and Ice

ice damaged tree

The weight of snow and ice can cause limbs to break or topple whole trees. How you deal with damaged trees after the snow or ice melts will impact their health now and for years to come. Keep the following tips in mind when caring for storm damaged trees and shrubs:

  • If shrubs are weighed down with snow, sweep the snow off the branches with a broom. Always sweep upward – sweeping from the top down can result in more broken branches. If the snow is frozen onto branches and will not easily dislodge by sweeping, allow it to melt naturally. Don’t shake trees and shrubs to remove snow.
  • For trees, be patient until the snow melts. There is little you can do to help trees weighed down by snow and ice. Trees and shrubs bent, but not broken, by the weight of snow and ice will often recover without special care. Learn more about how to care for storm damaged trees from this excellent Missouri Extension publication– First Aid for Storm Damaged Trees
  • For an in-depth understanding of how snow and ice can damage trees and the likely impacts on long term survival, download this exceptional guide from the University of Illinois, Trees and Ice Storms.
  • Once the snow has melted, assess the damage. If only small limbs and twigs are damaged, the tree will likely make a full recovery on its own. If many large branches are damaged, the tree may be able to recover with conservative pruning and care, and time. A certified tree care professional can help assess the damage and determine a plan of action.
  • Young, recently planted trees that have fallen over can usually be saved. Cover any exposed roots as soon as possible to protect them from drying out or freezing. Detailed instructions for saving these trees are covered in this Louisiana Extension fact sheet. Mature trees and trees with trunks over 10-12” in diameter that fall should be removed. In addition, trees that partially uproot and have over 1/3 of their roots exposed are typically beyond help and should be removed. Learn more about caring from fallen trees from this Florida Extension website.
  • Most shrubs damaged by snow and ice can be severely pruned if necessary. Wax myrtles are particularly prone to breaking when weighed down by snow and ice but can be cut back to within a few feet of ground level and will regrow, usually within one or two seasons. Most broadleaf evergreen shrubs (camellias, azaleas, hollies) and deciduous shrubs (spiraea, butterfly bush, Knockout rose) can be treated this way, but conifers (thuja, juniper, cedars, arborvitae) cannot. Conifers that break apart in ice storms will not recover and should be removed. Keep in mind spring blooming shrubs cut back now will not bloom this year. For more pruning tips, see this recent Extension Gardener post.
  • When pruning broken branches, know where to cut. Cutting in the wrong place can lead to decay, failure in future storms, and tree death. Smaller pruning wounds are preferred, even if they leave what looks like a stub. There is no need to paint over pruning cuts with wound dressings – in fact, this can actually harm trees. Learn more about proper pruning from these excellent references from University of Florida Extension:
  • Don’t over prune – leave as many limbs as possible. Removing more limbs than necessary reduces the tree’s ability to feed itself through photosynthesis that takes place in the leaves. Trees may look uneven or out of balance immediately after pruning, but will fill in within a few seasons. Help trees and shrubs recover from storm damage by applying a slow release or organic fertilizer in spring (March-April). Water recovering trees and shrubs during dry spells this summer and fall.
  • Never have a tree topped! This practice, which cuts back all large structural branches of a tree is extremely damaging and weakens trees in the long run. If topping is your only option, the better choice is to have the tree removed and replace it with a smaller growing, stronger wooded species. Learn more about why you should not top from this Purdue Extension fact sheet.
  • Some trees are weak wooded and more likely to be damaged in wind, snow and ice. Weak wooded trees commonly planted in North Carolina include: Leyland cypress, lacebark elm, Bradford pear, water oak, silver maple, green ash, willow and pecan. To minimize future damage, avoid planting these trees near structures. Learn more about what makes some trees more prone to ice damage from this New Hampshire Extension fact sheet.
  • Anytime you have a tree removed, replace it with a stronger wooded species. Trees more resistant to wind and ice damage for central NC include: crape myrtle, bald cypress, hickory, ironwood, ginkgo, and white oak.
  • Stay safe! Never cut limbs tangled in power lines – call the power company instead. Anytime removing a branch requires a ladder or a chainsaw, you should strongly consider hiring a tree care professional to do the job. Learn more about hiring a tree care professional from this NC Extension guide.
  • When pruning trees you wish to preserve, consider hiring a certified arborist. Pruning large trees and assessing tree health requires specialized skills and knowledge. If you are concerned about the health and strength of trees on your property contact a certified arborist to assess the situation. Certified arborists are highly qualified tree professionals who have passed the certified arborist exam offered through the International Society of Arboriculture. A list of certified arborists practicing in North Carolina can be found on their website, International Society of Arboriculture – Find an Arborist

More tips on dealing with storm damaged trees are available on NC State Extension’s Gardening Portal.

Learn how to prepare your landscape for snow and ice from this Extension Gardener post.

Thanks to Guy Meilleur, ISA Board Certified Master Arborist for reviewing this page and making suggestions for its improvement.

Use Extension Search to find research based information from Cooperative Extension systems across the U.S.

Subscribe to the Chatham Gardener email list to receive timely updates on sustainable lawn, garden, and landscape care for the central NC Piedmont. To subscribe:

Written By

Photo of Charlotte GlenCharlotte GlenState Coordinator, NC Extension Master Gardener Program Chatham County, North Carolina

Updated on Jan 6, 2017

Will the Cold Harm My Plants?

cold

Most of central NC lies within USDA hardiness zone 7b, which has an expected average minimum temperature of 5 degrees. While it is rare, temperatures can fall below this expected minimum and cause damage to some landscape and garden plants.

When Is Damage Most Likely To Occur?

Many factors impact whether or not a specific plant is damaged by cold temperatures, including snow cover. Extremely cold temperatures often follow a winter storm. If the storm left behind a blanket of snow, plants are less likely to be damaged – especially low growing plants, bulbs, and dormant perennials covered by snow.

Time of the year also makes a difference. When extreme cold occurs in the early part of winter (Jan – Feb), most landscape trees and shrubs, fruit trees, and berry plants are fully dormant and unlikely to be damaged.

Later in the season (March – April), many plant parts are more susceptible to temperatures below freezing, especially flower buds. Late freezes are particularly damaging if they are preceded by a warm spell.

Plants Most Likely To Be Damaged

Plants growing in containers are exposed to colder temperatures than those rooted in the ground. Containers that can be moved should be brought into a garage or shed, or, at a minimum, pushed up against the eaves of the house. Containers too large or heavy to move can be completely surrounded and covered with several layers of insulating materials.

Trees and shrubs that are marginally hardy in our region are more at risk of cold injury, especially non-native varieties rated as hardy to zone 7b or 8. Figs and gardenias are the plants most frequently damaged by single digit temperatures in NC Piedmont landscapes.

Protecting Prized Plants

While figs and gardenias are not likely to be completely killed by cold temperatures experienced in central NC, their stems may freeze – causing all above ground parts of the plant to die back.

When this happens, new sprouts should emerge from the base of damaged plants in spring. Figs that freeze back in winter typically regrow vigorously but are not likely to ripen fruit for a season or two, while freezing back to ground level will delay flowering in gardenias.

For a prized plant, such as an heirloom fig bush or specimen gardenia, it may be worth the effort to provide extra protection.

If you wish protect an entire fig or gardenia bush, one option is to surround each bush with a cage made of chicken wire and fill it with loose, dry mulch or straw before temperatures plunge. Remove the cage as soon as temperatures rise above freezing.

Another option is to build a frame around the plant and completely cover the frame with double layers of plastic or frost protection cloth, then place a heat source underneath. Ensure the frame’s covering reaches all the way to the ground and is well secured.

Old-fashion incandescent bulbs or Christmas lights are often used as the heat source, but they have to be the older, less energy efficient types to be effective. Newer LED bulbs give off little heat – that’s part of what makes them so energy efficient.

A local gardener shared that she uses a slow cooker filled with water as a heat source to keep her covered plants just above freezing. No matter what you use, take extreme care to prevent fire and electrical malfunctions.

When spring does arrive, don’t be too quick to give up on cold damaged plants. Even if the entire top is frozen, gardenias, figs and several other woody plants will recover by sprouting from the base or roots, though it may be May or even June before new growth emerges.

See more tips for protecting plants during cold snaps.

Not sure of your landscape plants’ hardiness? Find out the USDA hardiness rating and much more from the N.C. Cooperative Extension Plants Database

Additional Extension Resources:

Use Extension Search to find research based information from Cooperative Extension systems across the U.S.

Visit your local Cooperative Extension center to learn more about gardening and landscape care. Find your county Extension center or post your questions to be answered online via Extension’s ‘Ask an Expert’ widget.

Subscribe to the Chatham Gardener email list to receive timely updates on sustainable lawn, garden, and landscape care for the central NC Piedmont. To subscribe:

Written By

Photo of Charlotte GlenCharlotte GlenExtension Agent, Agriculture – Horticulture Chatham County, North Carolina

Updated on Jan 7, 2017
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