|Our blackberry row|
There is plenty of advice available about selection, planting and care. Oklahoma State University Fact Sheet 6215 about growing blackberries in the home garden is at https://bit.ly/2L2nyAp. Another good resource is at https://bit.ly/2sfgDg3.
During fruiting season blackberries need 2 to 4 inches of water a week. Their roots are shallow so watering more frequently at ground level rather than a deep soak or watering overhead will give the best results. A mulch made of organic material such as straw can be spread around them to keep the moisture level consistent.
The fruit should be harvested every other morning and only the dull-black ones should be picked. Shiny berries aren’t ripe yet. The fruit from thornless blackberries does not keep well so refrigerate soon after picking.
Right now the shrubs are producing next year’s fruiting canes and they must be pruned or tipped to about 4 feet tall. The lateral branches should be pruned to 12 to 15 inches long to keep the plants upright and full of berries next year. A Texas grower made a video illustrating how he prunes the 700 plants on his farm (https://bit.ly/2sg8wQp)
|Tip-prune the non-fruiting canes now|
Remove all the dead branches to prevent disease. While doing maintenance you will see new plants emerging a foot or two from the main plant. Remove these suckers and plant elsewhere or put them in containers to share with other gardeners. Leaving the suckers in place will create wide rows that are challenging to take care of.
Thornless blackberries are planted in Feb. Four plants will supply a family of 4.