Blackberries are distant cousins to roses, which is evident in the brambly bushes and small, flowers that proceed the berries. Unlike roses, blackberries are prized for their fruit rather than for their flowers. Blackberries are native across the south and up into near-arctic regions in Canada. Blackberries are also cultivated and are the main export of Oregon. Although some species can become invasive, with proper care, a blackberry bush will remain contained, and will produce fruit for up to 20 years.
Test the soil's pH before preparing your berry beds with a pH testing device with a probe. These devices are sold at many garden stores. The ideal pH for your berries is a very acidic 5.5.
Loosen the soil to a depth of 8 inches by pushing a rototiller over it. Spread powdered sulfur over the soil according to package directions. Mix it into the soil by pushing your rototiller over the soil again.
Water the soil with a garden hose and wait approximately 72 hours before planting blackberries.
Lay out a row for your blackberries by placing a garden hose along the row length.
Erect a trellis along the row by digging post holes along the length of the garden hose. Your post holes should be spaced 30 inches apart and 18 inches deep.
Place fence posts that are between 4 and 6 feet long into the post holes. Fill in the holes with dirt. Affix fencing wire to the posts at a height between 38 and 40 inches above the ground. Secure the wire to the posts with fencing staples and a hammer.
Plant blackberry bushes approximately 4 to 6 feet apart in rows with 8 feet of space between them. To do this, dig a hole that is slightly larger than the root ball. Spread roots out in the hole and cover with dirt.
Tie the individual canes of the blackberry bushes to the trellis wire with garden twine in a fan shape. Any canes with blackberries on them are approximately two years old. Canes with no growth on them are one year old. Blackberries only produce berries on canes that are two years old. Seperate canes by age with all one year old growth on one side of the fan shape, and all two year growth on the other. Two year growth will be longer and will produce berries. Younger bushes may not yet have two year old canes. In which case, tie blackberry canes into a half-fan shape on the trellis.
Fertilize plants with a balanced (10-10-10) fertilizer once each spring. Add fertilizer according to package directions. Spread fertilizer in a ring around the bushes that is 12 inches in diameter. Scratch into the soil with a cultivator and cover with pine straw to mulch.
Water bushes only in drought conditions.
Remove two year old canes by cutting them off at the ground with sharp pruning shears. As new canes emerge, tie them onto the trellis in the empty spot on the trellis where your two year growth had been.