Blueberries for Texas
Drs. Larry Stein, Jim Kamas & Jerry Parsons
Professors and Extension Horticulturists Berries, berries and
more berries. . . . Texas is indeed a land of berries. From trailing
dewberries in Central and South Texas to huckleberries in the
acid soils of East Texas, there are many adaptive berries for
the erratic, and environmentally-challenging growing conditions
of our large state. The most planted and adapted berry planted
to date has been the blackberry. However, blackberry thorns and
the biennial nature of the plants makes even them a challenge
in a small landscape setting. Hence, there may be an opportunity
for a different berry to become "King of the Hill".
The berry which comes to mind is the blueberry. Blueberries are
a very popular fruit in the United States because of their unique
flavor, small edible seeds, and ease of preparation. Blueberries
can be eaten fresh or used for jelly, jam, pies, pastries, or
juice. Blueberry fruit is also low in calories and sodium, contains
no cholesterol, and is a source of fiber. A major constituent
of the fiber is pectin, known for its ability to lower blood cholesterol.
Blueberries contain measurable quantities of ellagic acid, which
has inhibiting effects on chemically induced cancer in laboratory
studies. Blueberry juice also contains a compound that prevents
bacteria from anchoring themselves to the bladder, thereby helping
to prevent urinary tract infections. Obviously, such great fruit
attributes would make any homeowner long to culture blueberrie.
Still the production of blueberries has a few challenges of its
own. The soil or growing medium pH is critical for successful
blueberry culture. This funny expression-- pH -- is a measure
of the hydrogen ion concentration in the soil solution or simply
put, whether the soil is acid (less than 7.0) or alkaline (7.1
and above). Rabbiteye blueberries are one of the few crops that
require very special soil or growing medium; a pH of 4.0 to 6.0
is required for good plant growth; the plants will not live in
soils or potting mixes with a pH above 5.5. The plants' feeder
roots are very close to the surface and they do not have root
hairs; therefore, good soil moisture management and mulches will
be needed. One may be surprised as to why we would recommend such
an exacting, low soil pH plant for planting across a state which
only has a small amount of such soil, which is mainly in East
Texas. Simply put, it is because of the potential to produce an
acceptable amount of fruit on a containerized plant with very
few pest problems.
The blueberry is not grown
as a flowering plant but the combination of red wood, dark green
and plump flower buds make it an attractive landscape plant all
during the year.
The plant is attractive in a container and displays spectacular
fall color for several weeks.
Blueberry plants have beautiful
red and yellow leaves in the fall and
display their fall foliage for several weeks.
Sure there are some insects and diseases which
bother these plants, but if the plants are maintained in a healthy
state of growth, few if any pest applications will be needed and
a good quantity of fruit will still be produced. Blueberries are
relatively small plants and can be protected with plant covers
if bird or insect pests become a problem. Since, few of us will
have soil which will be conducive to blueberry culture in the
soil, we will assume that all will grow them in containers. The
plants should be planted in a well-draining whiskey barrel size
(20-30 gallon) container. Adequate drainage is a key to success.
A soilless peat-base mix which drains rapidly should be used.
Ideally, when you pour water around the base of a plant, water
should soon be coming out of the bottom of the container. This
not only indicates proper drainage but also enables leaching of
fertilizer salts which, if accumulated, can damage a blueberry
plant's roots. Soilless mixes should be soilless-- absolutely
no soil! Regardless of how wonderful you think your soil is, when
soil is put in a container it loses many of its beneficial qualities.
Many suitable types of soilless peat-base mixes are commercially
available. A soilless peat-base mix should be disease and weed-free,
retain adequate moisture after watering yet is well-drained and
lightweight. Essentially you will have created an "acid bog"
with peat-base potting mix to assure good growth. Blueberries
thrive in 100 percent peat moss, so there is no limit to the amount
you can use and if you are doubtful about the pH of the potting
mix you plan to use, simply add more peat moss. Be sure to incorporate
a slow release fertilizer such as Osmocote into the peat-base
potting mix . Avoid the use of rapid-release, nitrate fertilizer
and use an acid-based, water soluble fertilizer once a month during
the growing season after the plants are established. Once you
have formulated or purchased a well-drained soilless peat-base
mix in which to grow the blueberry plant, be sure that the container
being used has adequate drainage capabilities. If a water-tight
container is being used, drainage holes will have to be drilled.
When considering drainage holes, the old saying, "The more,
the merrier" definitely applies. Also, don't worry about
lining the bottom of the container with course gravel or charcoal
to expedite drainage. Recent research indicates that such a gradient
in materials actually impedes drainage. If a loose soilless mix
is used, water drainage through drain holes will not be a problem.
The taller the container, the more difficult it is to obtain even
water distribution. The half whiskey barrels or 20 - 30 gallon
size containers are your best bet. Heavy duty coasters can be
attached to the bottom of the containers before potting mix is
added to allow ease of movement even though blueberries will not
have to be protected from cold weather--they require cold weather
in order to fruit. Another critical key to successful blueberry
production is sunlight. All berries require full sunlight all
day for maximum production. Minimum is eight to ten hours of direct
(not filtered) sunlight a day. Not only do the plants require
full sunlight when they are planted, but also as they continue
to grow. Over time if they become shaded by trees in your landscape,
their production will be much less. Some blueberry varieties require
cross pollination so variety selection will be critical. However,
Tifblue has been shown to be self-fruitful and is the most universally
outstanding rabbiteye blueberry grown to date.
Even though this label indicates
that the Woodard blueberry variety is recommended for pollination,
a pollinating variety is not necessary for a full crop of the
The fruits are large, light blue and ripen late in the season.
The bush is vigorous and very productive. Tifblue is more cold
hardy than most rabbiteye blueberries varieties and receives adequate
chilling (cold temperatures) to fruit as far south as Pleasanton,
Blueberry plants retain
their beautiful fall foliage longer than peach
trees but must still have a certain number of hours of temperature
45 degrees F. to leaf and fruit normally.
Tifblue rabbiteye blueberries require little pruning. Lower limbs
can be thinned out to keep the fruit from touching the soil, and
excessively vigorous upright shoots can be thinned out several
feet from the ground to keep the center of the bush open and to
keep the bearing surface within reach. Spindly, weak, or dead
branches should be thinned out annually during the dormant season.
Blueberries have a very fine and fibrous root system so mulching
is a must as well as frequent irrigation. Use some sort of organic
mulch such as spaghum peat moss but avoid the manures since most
are alkaline and salty. Because culturing plants in containers
severely limits their root spread, frequent watering and fertilization
are essential. As emphasized earlier, the well-drained soilless
peat-base mix--necessary for good aeration--needs frequent watering.
As plants grow larger, more watering is required because water
is being absorbed and transpired. As temperatures increase more
water is evaporated from the mix and transpired from the plant.
Young plants growing in cool weather may require watering only
once every two or three days. Check the moisture level of the
mix with your finger before watering, i.e., water the mix, not
the plant. If you feel moisture with your finger DO NOT WATER;
more plants are killed by over watering than by being too dry.
Remember, container size and soilless peat-base mix used will
have a lot to do with the watering regime followed. Blueberries
also require good-quality water with low sodium and bicarbonates.
It would be best if you could use rainwater or air-conditioner
condensate for irrigation as most of the water across the state
is high in salts especially calcium. Water large plants thoroughly
once per week rather than daily and keep a deep layer of mulch
around the plants. Water is especially important during the long
fruit-ripening period. Rabbiteye blueberries are a non-climacteric
fruit and should be allowed to ripen on the bush. The fruit of
the Tifblue variety will ripen over a 4 to 6 week period. A normal
season can extend from late May to late July. Don't pick the berries
until they are fully ripe; otherwise the fruit will be bitter.
Once the berries begin to ripen they should be picked every 3
to 5 days.
As seen in this picture
of ripening Tifblue blueberries, some berries are ripe while some
are green and immature.
Berries must be fully ripened or blue before harvesting.
Birds seem to be the key wildlife competitors for the delicious
fruit. A mature bush can produce 15 lbs of berries.
So now you know the "secrets" of successfully producing
one of the most delicious and health-giving fruits, blueberries,
in regions which were previously considered off-limits to these
acidic soil loving delicacies. These same growing techniques should
be used when growing other acidic-loving plants such as azaleas,
camellias and gardenias in alkaline soil areas. However, these
flowering plants thrive in a growing exposure which receives morning
sun and afternoon shade. For a video about this procedure, see: