Blackberries are a bramble plant that produces sweet berries in late summer. The plant is native to North and South America, Europe and Asia and hardy to plant in USDA growing zones 5 through 10. Blackberry canes grow well in home gardens in central and southern Michigan, where winter temperatures do not get colder than -10 degrees F. Choose a planting location that did not previously grow tomato, pepper or potato plants, as these harbor a fungus that is deadly to blackberries.
Choose a planting location that has well-draining, acidic soil in full sunlight. Work 2 to 3 inches of organic compost in the soil with a tiller to a depth of 10 inches. Test the soil pH to verify it is between 5.0 and 7.0. Work ground rock sulfur into the soil two weeks before planting to lower the pH number, if necessary.
Dig a 2- to 3-inch hole and set the blackberry canes in so the roots are spread out. Cover the roots with soil and gently pack to hold in place. Space the blackberry plants 2 to 3 feet apart in rows at least 4 feet apart.
Water the blackberry canes generously after planting. Provide supplemental water to the canes during the growing season by soaking the soil to a depth of 6 to 10 inches. Do not allow the soil to dry out or create a pooling of water around the plant.
Apply a 4-inch layer of straw or pine bark mulch around the canes to decrease weed growth and increase soil moisture. Mulch will also insulate the roots during the cold Michigan winters.
Fertilize blackberry canes in the second year of growth at the time of blooming and again after the berries are harvested. Apply 5 pounds of a 10-20-10 fertilizer for each 100 feet of planting row. Water the soil well after applying fertilizer.
Prune the canes each spring to remove damaged and dead branches. Summer prune the plants by cutting 3 inches off the end of each new growth cane. Remove all two-year-old canes after harvesting the berries.