The blackberry plant produces an edible berry that grows on biennial canes with perennial roots. The plants are native to the northern hemisphere. Blackberry plants produce between 3 to 10 pounds of berries in their two year life-cycle. Fruit normally ripens in Arizona during May and continues for 3 to 4 weeks. The canes reach a height of 5 to 6 feet, with some varieties reaching 12 feet in height.
Choose a compatible variety for Arizona, such as Rosborough, Womack or Brison.
Plant the blackberry canes in well-drained soil during late January to March. Space the canes 3 to 4 feet apart in each row. Space the rows 8 to 10 feet apart. Water the canes well immediately after planting.
Water the canes every day while the plants are establishing with a drip or soaker irrigation system at a rate of 1 to 2 inches of water per week. Water established plants every other day in the same manner. Provide additional water during hot weather and while the plants are flowering and fruiting.
Fertilize in a two foot circle around the canes with a 10-10-10 fertilizer one month after planting. Fertilize again in June or July. Water the canes well after fertilizing to promote absorption.
Remove all two year old canes after the fruiting season. Leave the young leafy vegetative canes. Prune two year or older vegetative canes to 3 feet in June by removing the top 2 to 3 inches. This will promote lateral branching.
Shade blackberry canes late in the season to prevent sunburn or sun scald on the plants by using a mesh garden canopy or trellis.
Propagate new plants by digging new shoots that grow from the roots. Replant these shoots to start new blackberry plants.