Blueberries
High maintenance fruits with rich rewards!
Blueberries are an attractive semi-evergreen shrub with colorful foliage in the fall, white to light pink blossoms in the spring, and large, sweet, delicious berries in mid-summer. You will be happily rewarded if you are up to their rather demanding growing conditions!
Blueberries have two significant requirements for success:
- they must have excellent drainage, and
- they require very acidic soil to thrive and produce a crop.
Rabbiteye blueberry varieties are generally regarded as best for Texas.
Blueberries require a soil pH of 4.5 to 5.5. Central Texas soil is very alkaline due to the limestone parent material. We cannot permanently change the pH of our soil and water and so we recommend growing blueberries in a container filled with a soil-less mix. This will keep the pH in a range acceptable for the plant. The soil should drain freely as blueberries do not like soggy conditions; water poured into the container should be draining from the bottom nearly immediately. A container of 20 gallons (or larger) in size will maintain long-term production. Blueberries produce best in a full-sun environment, though they will appreciate late afternoon shade.
When filling a (20 gallon) container we mix a blend of:
- 4 parts Coco Coir Fiber
- 1 part Acidified Cotton Burr Compost
- 1 part Happy Frog Soil Conditioner
- and 1 cup of Minerals Plus
A 2 to 3 inch layer of mulch should be used to protect the shallow roots. Small applications of Dr. Iron (or a sulfur product approved for containers) can help keep the pH low. Blueberries require good soil fungal populations, so adding a mycorrhizal supplement at planting time can increase vigor.
Blueberries do not have high fertilizer requirements. First-year plants or plants with lots of fresh leaf growth do not need to be fertilized. A healthy plant should put on approximately 1 foot of new growth per year. Fertilizing should be necessary only if growth is less than that. Fertilizer should be applied sparingly as excess nitrogen is detrimental and can stunt growth. Extension offices in “blueberry country” recommend low nitrogen fertilizers applied in early spring as growth starts, and twice more, approximately every two months, if necessary. Blueberries benefit from magnesium and iron; the addition of micronutrients and minerals as mentioned above can maintain proper levels.
Plants should receive 1 to 2 inches of water per week. For convenience, consider that one-half to one gallon of water per square foot of root zone per week. Due to Austin water being so alkaline, use only rainwater for watering the plants if at all possible. If city or well water is all that is available, 2 teaspoons of household vinegar added to a gallon of water will help maintain a low pH source of irrigation water.
- At planting, remove older twiggy growth from the base of the plant and leave strong new growth.
- At least the first year, remove all blossoms, to prevent fruiting and encourage strong growth.
- For the next two years, remove dead or damaged branches and spindly growth at the base of the plant.
- After the third year, pruning should focus on removing unproductive wood and generating replacement wood with the goal of having a balance of branches that are 1 to 5 years old.
Prune annually in the winter, following these steps:
- Cut out dead, damaged, and diseased wood.
- Remove small sucker shoots and weak twiggy growth at the base.
- Remove low spreading branches that will be shaded and touching the ground with fruit.
- Remove one or two of the oldest canes each year, cutting back to the ground or to a strong new side shoot.
- If more than two new canes grew from the crown the prior year, remove all but the two healthiest canes at crown level.
- Remove weak twiggy wood from the top and outside branches.
- Prune out crossing branches.
- If plants overbear, cut back some of the branch tips where most of the flower buds are located.
- Extremely vigorous new shoots should be tipped or headed back to encourage branching and fruiting.
Blueberries have few pests, though you will be forced to protect your harvest from birds, who will find them to be a favorite fruit. Rabbits like to chew on branches that they can reach. Diseases such as powdery mildew, stem canker, and mummy berry can be an issue, but an organic fungicide applied weekly from bud break to blossom drop, can help keep your plants healthy.
Harvest berries every 5 to 7 days. Berries are at their best a couple of days after turning blue. Berries should easily fall into your hand when ripe, do not force them off the plant. They will not ripen once they are picked. If you wish to store berries, freeze them in a single layer on a sheet pan, then toss in a zipper-top bag and place in your freezer.
The numbers in brackets show Chilling Hours. Note that while these plants can produce without a pollenizer, yields will be higher when planted with a second, or even a third bush of the same group (Rabbiteye or High Bush) of blueberry.
Rabbiteye Varieties — Vaccinium ashei
Traditionally best type for Texas. Native to the southeast US.
Climax (400-450)
A vigorous bush with an upright habit and medium-sized berries ripening from late May to June. The plant may need to be protected from late freezes.
TifBlue (550-650)
Bush has an upright habit with small- to medium-sized berries ripening from late June to July. Vigorous and very productive. Considered one of the best in Texas.
Pink Lemonade (450)
Upright beautiful colorful plant all year. Fruit is pink, sweet, and delicious.
Premier (550-600)
A productive cultivar with large berries ripening from late May to early June.
Southern High Bush Varieties — Vaccinium corymbosum or V. darrowii
Southern selections of high bush blueberry that is native from east Texas to Georgia up to Canada.
Emerald (250)
Early ripening high yielding variety with very large firm fruit with excellent flavor.
Misty (300)
Very vigorous upright variety. Very sweet, a heavy producer. Early ripening and heat tolerant.
Sunshine Blue (150)
Semi-dwarf upright bush great for pots. Can tolerate slightly higher pH. Heavy producer of delicious berries.