Blueberry Chill Hours. What are they?

BlueberriesBlueberries are a perennial shrub that is relatively easy to grow.   Rabbiteye types are popular statewide and their fruit is delicious!  You may have read in agricultural science articles about “chill hours.”   What are they?  Why do they matter?  To answer those questions we are going to turn to science so, please pardon the charts!

According to UGA scientists Gerard Krewer and D. Scott NeSmith (Blueberry Cultivars of Georgia) blueberries require a certain number of chill hours each winter to produce the optimum fruit harvest.  Chill hours are the number of hours of winter temperatures 45 degrees F and below.  If blueberry plants do not receive the adequate amount of chilling, bloom and leaf development can be late and erratic.  This can result in a lackluster harvest.  To sum it up – blueberries have to have some cold winter weather.

Rabbiteye Cultivar  Chilling Requirement
Premier 550 hours
Climax 400 to 450 hours
Brightwell 350 to 400 hours
TifBlue 600 to 700 hours
Powderblue 550 to 650 hours
Vernon 500 to 550 hours

How do we know how many chill hours we have had in our area?  The weather stations of georgiaweather.net have chilling hours calculators.  As of February 22nd:

Weather Station Number of Chill Hours between Oct 1, 2015 and February 22, 2016
Blue Ridge 1357
Atlanta 941
Cordelle 661
Valdosta 369

So what does this all mean?  As noncommercial blueberry growers, it can give us some scientific information about our blueberry harvest and it gives us some insight into plant biology.  It also gives us another reason to watch the weather forecast and welcome cold winter weather.

If you don’t grow blueberries yet, give it a try!  See Home Garden Blueberries for more information.  Also contact your local UGA Extension office.  Many of them have plant sales this time of year and blueberries are often for sale.

Happy Gardening!

Congratulations Georgia Certified Plant Professional and GGIA Jr. Plant Professional Graduates!

On Thursday, January 28th, the testing room at the GGIA Wintergreen Conference was buzzing with industry professionals and middle school students who gathered to take the written and plant identification exams for the Georgia Certified Plant Professional and the GGIA Jr. Plant Professional Certification Programs. Congratulations to the six industry graduates who achieved professional certification and the six middle school students who certified in the junior division.

Georgia Certified Plant Professional Graduates:
Anna Testa
Dan Smith
Michele Sarti
Amy Rothenberg
Amy Collier

Georgia Certified Landscape Professional Graduates:
Charles Daniel

Please congratulate these graduates when you see them.

Special thanks to GGIA executive director Chris Butts, Jennifer Addington, Sarah Mickens, and the entire group of energetic staff and volunteers who sponsored the testing site, provided reservations, contributed prizes for the Junior certification, and hosted a terrific conference that brought the industry together. Thanks to Josh Allen and the Ag Education Instructors for challenging their students and creating this opportunity for young people, the future of the industry. Thanks to Wayne Juers for thoughtfully collecting, presenting, and labeling an excellent variety of fresh plant samples for the participants. Thanks to Betsy Norton of Going Green Horticulture for speaking to the Ag Education students about careers in the green industry. Thanks to Aaron Paulson, Katherine Buckley, and the students of Gwinnett Technical College for helping with setup, speaking to the Ag students about educational opportunities, providing prizes, and helping with all the details to make it happen. I want to thank Todd Hurt and Becky Johnson for testing support and all of the University of Georgia Extension Team who provided educational outreach and support to the green industry.

For more information about the Georgia Certified Plant Professional, Georgia Certified Landscape Professional, and other programs visit the UGA Center for Urban Agriculture certification page at https://ugaurbanag.com/certification/.

Pollinator Protection Plan for Georgia

Pollinator Protection Plan for Georgia

Because of real concerns about our pollinator population the Environmental Protection Agency (EPA) asked each state to develop a customized pollinator protection plan with recommendations on improving pollinator health.  This is not a regulatory document but just guidelines to help our pollinators.

Georgia’s plan is finished!  Protecting Georgia’s Pollinators (PGP) was developed as a joint effort between UGA’s Department of Entomology and the Georgia Department of Agriculture.  The author committee is made up of Jennifer Berry, Kris Braman, Keith Delaplane, Mike Evans, Philip Roberts, and Alton Sparks.  Those of you who are beekeepers may recognize several of these names as people heavily involved in pollinator research.

The draft of the plan was sent to over 35 groups across the state for their input – Georgia Beekeepers Association, Georgia Fruit and Vegetable Growers Association, the Peach Commission, the Blueberry Commission to name a few.  The result is a plan that has a role for all of Georgia’s citizens.

As community and school gardeners we have a vested interest in pollinator health.  More pollinators means more food from our gardens.  Not to mention the beauty of enjoying the insects at work.

Guidelines from the pollinator plan that we can garden by include:

If possible leave areas of your property permanently undisturbed for soil-nesting bees.  Sun-drenched patches of bare soil, roadsides, ditch banks, and woodland edges are prime bee habitats.

Dedicate pollinator habitat spaces in your garden.  UGA’s Pollinator Spaces Project has many resources to help with this.  Bees need a season-long unbroken succession of bloom.  Many plant species bloom in the spring.  Remember to plant plants to bloom in mid- to late-summer including Vitex, sages, and sunflowers.  Your local UGA Extension office will have information on what pollinator plants grow well in your area.

Pollinator Protection Plan for Georgia
Pollinator spaces are useful and beautiful!

Know the beekeepers in your area.  If your garden has a bee hive you want to be very careful about pesticide application and you will want to review in detail the section on pesticide users in the plan.

Pollinator Protection Plan for Georgia
Bee hives can be located in urban areas

Consider increasing bee nesting sites by providing bee homes.  These consist of solid wood pre-drilled with 1/4 to 1/2 inch holes that are at least 3-inches deep.  It is important that the tunnels terminate in dead-ends.  These are easy to create and a nice addition to any garden.

Pollinator Protection Plan for Georgia
A easily constructed bee home – photo from PGP

Educate your gardeners about insect behavior.  For example, the flight and nesting behavior of certain solitary bees happens in bursts of extreme activity.  In the spring or summer you may see a large number of bees flying out of tunnels in the grass over your garden all at once.  These are solitary bees and they are gentle, and their sting risk is extremely low!  Enjoy watching them!

Pollinator Protection Plan for Georgia
Digger Bee Nests

If you think insects are a problem in your garden take steps to correctly identify the insects and determine, with the help of your UGA Cooperative Extension Agent, if remedial action is necessary.

If your garden is located in a park or other public space that is maintained by local landscape crews, make sure that if they need to apply insecticide for turf pests that they mow the grass immediately before applying the pesticide.  The mowing will get rid of weed flowers that may attract bees.

White Clover
Clover, a bee favorite, is often found in lawns.

Follow all pesticide label directions and precautionary statements.  THIS IS THE LAW.  EPA is now requiring a “Protection of Pollinators” advisory box on certain pesticides labels.  Look for the bee hazard icon and instructions for protecting bees and other pollinators.

Pollinator Protection Plan for Georgia
Bee Hazard logo – photo from PGP

Take some time to look at Protecting Georgia’s Pollinators and you will see we all have a role to play.  If you need any information about the plan or protecting pollinators contact your local UGA Cooperative Extension Agent.

Happy Gardening!