blueberries

Blueberry Pollination in Your Community or School Garden

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With the recent cold damage to the commercial blueberry crop in South Georgia, the blueberries in our community, school, or home gardens are all the more precious this year.   As a result, it seems like gardeners are paying more attention to their blueberry flowers.  I have gotten several emails asking about slits appearing in the sides of blueberry flowers.  This is not unusual and it probably happens every year, gardeners just don’t notice it.

The slits are made by carpenter bees who are “robbing” the flower.  They chew slits in the sides of the flowers and get the nectar without having to go into the flower.  A result of robbing is that the bees don’t leave or pick up any pollen.   Pretty sly bees, right?  Research shows that this action still results in some pollination, it is just not ideal.   Other bees may use these slits as well to retrieve whatever nectar is left.

Blueberry Pollen is Heavy

Blueberry pollen is heavy and sticky.  It does not move around easily and isn’t wind blown.  The blueberry flower shape does not lend itself to adequate self-pollination so pollinators are needed even with the self-pollinating types of blueberry plants.

Blueberry Pollination in Your Community or School Garden
Southeastern Blueberry Bee. Photo by Hannah Barrack of NC State.

Bee Pollination

Several native bee species pollinate blueberries including the Southeastern blueberry bee.  This bee also pollinates several flower types that bloom at the same time.  The male Southeastern blueberry bee has a yellow face.

The smaller native bees are shown to be superior pollinators in these plants.  You will also see bumble bees in the blueberry patch.  They vibrate their flight muscles inside the flower aiding in pollen exchange, flower sonication.  Also, honey bees are often brought into blueberries fields to aid in pollination.  To learn more about bees in the blueberry patch visit North Carolina State’s Blueberry Pollinators .

Blueberry Pollination in Your Community or School Garden
Honey bees on the fly! Photo by Joe Thompson.

I enjoy pulling up a chair near my blueberry plants to watch the pollinators at work.  Try it and you will be amazed at the different insects you see.

If you don’t have blueberries in your community or school garden, why not?  They are a fantastic addition to the garden.  Being perennial shrubs they add a nice permanent shape to the space.  School gardeners should look at later season varieties.

Happy Gardening and I wish you all a very large blueberry harvest this year!

Blueberry Chill Hours. What are they?

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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!

Planting Blueberries in the Georgia Garden

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Blueberries About to Ripen
Blueberries About to Ripen

Blueberries are a tasty addition to any community garden.  The fruit is high in antioxidants,  and the plants are easy to manage.  Fall is a great time to get them in the garden.

Since blueberry bushes are perennials shrubs, it is advantageous to plant them in a community part of the garden.  Along a fence that gets plenty of sun is a possible spot.  This way no one is taking up permanent plot space with the bushes and everyone can enjoy the fruit. D. S. NeSmith, a research horticulturist from UGA, has a great publication on Home Garden Blueberries.

For community gardeners the best type of blueberries to plant is the rabbiteye type.  The most important thing to know about growing rabbiteye blueberries is that you need to plant more than one variety for cross-pollination. If you choose your varieties from slightly different ripening times, you will have a longer harvest.  For early season rabbiteyes look for Alapaha, Climax, Premier, Vernon, or Titan.  For mid-season types try  Brightwell, Powerblue, or Tifblue.  Ochlockonee, Baldwin, and Centurion are all late season varieties.  Titan was released in 2011 and it is the largest fruited rabbiteye variety available to date.   Vernon also has large fruit.

Blueberries along a community garden fence.
Blueberries along a community garden fence.

Choose a planting site that gets at least a half-day of sun.  Anything less and the plants may grow but you won’t get a large amount of fruit.  Blueberries like our typical acidic soil and need a soil pH of 4.5 to 5.2.    The standard spacing for rabbiteyes is 5 – 6 feet between plants as they can get large.   Before planting till the soil deeply, 8 to 12 inches, and make sure your site doesn’t tend to stay wet.  The best time to plant is in the fall through the very early spring. This gives time for the roots to develop before the heat of the summer.  Mulch will be needed and it is important to keep weeds and grass away from the plants.  Your local UGA Extension Agent can answer any questions you have about blueberry planting.

If you are interested in incorporating blueberry bushes into your community garden do some planning before you plant.

Is the entire community interested in blueberries?  What is the best site?  Who will care for them?  How you will divide the fruit?  Remember that deciding these things early prevents problems later on.

Happy Gardening!

 

 

 

 

 

 

 

Bountiful Blueberries

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Blueberries About to Ripen
Blueberries About to Ripen

This is a good blueberry year.  The rain we had in the early spring and the cold winter temperatures helped make the berries plump and delicious.  They are fun to snack on as you work in the garden and fun to take home for later.

Many gardeners are frustrated when the birds get to the berries first.  One recommendation is to put netting over the plants.  This is not a perfect solution as it makes it hard for you to harvest the blueberries.  And, it is extremely sad to deal with a bird caught in netting.  Some gardeners tie aluminum pie pans to the bushes.  The sun reflecting off of the pan and movement of the pans with wind can help deter birds.   Experienced gardeners will advise to just keep the bushes picked.  As soon as the berries are ripe harvest them; don’t leave the blueberries on the bushes ripe for very long.  This seems to be an invitation for birds.

Now that you have an abundance of delicious berries what can you do?

Best defense against the birds - keep the blueberry bushes picked!
Best defense against the birds – keep the blueberry bushes picked!

To store them frozen, freeze them in a single layer on a cookie sheet.  After they have frozen, pack the berries in containers or freezer-type plastic bags and return them to the freezer.  You can take them out of the containers a few at a time.   Wash the berries just before you use them.  This way you can enjoy blueberry muffins and cobblers all winter!  You can also put up some blueberry jam.  Canning supplies are found in some big box stores as well as many local hardware stores.   Preserving Food: Jams and Jellies has great information for the beginning jam maker, including a berry jam recipe.

For summer eating, nothing is as good as a Blueberry Crisp.  This recipe is from a Cobb County Master Gardener Volunteer, Beth St. Jean, and is published in Farm to Table which is a collection of recipes from the Master Gardeners of Cobb County.  It is the perfect use for blueberries!

Blueberry Crisp

  • 3 T all-purpose flour
  • 2 T granulated sugar
  • 6 cups fresh blueberries
  • 1/4 cup lemon juice
  • 1 cup brown sugar
  • 2/4 cup all-purpose flour
  • 3/4 cups quick-cooking oats
  • 1  1/4 tsp ground cinnamon
  • 1/2 cup butter

Preheat oven to 375 degrees F.  Stir together in a large bowl the flour and sugar.  Gently toss in blueberries and lemon juice.  Spread berry mixture in bottom of ungreased baking dish.  Set aside.  To prepare the topping, combine brown sugar, flour, oats, and cinnamon.  Cut in the butter with a pastry blender until the mixture resembles coarse crumbs.  Sprinkle mixture evenly over the berry mixture.  Bake uncovered for 30 minutes or until top is golden brown and edges are bubbly.  After cooling for 45 minutes, may be served with ice cream on top!

If you don’t have blueberries in your community garden yet, we will discuss how to do that in a later post closer to the appropriate planting time.  Meanwhile, know that your local UGA Extension Agent can help you with any blueberry plant questions or problems.

Happy Gardening!