Plant in early spring. In the Midwest blackberries need to be planted in early spring. Select blackberry plants hardy to your zone. You can choose from semi-erect bushes that do not require trellising to the more traditional trailing varieties that should be trellised for the best results. Blackberries are self fruitful, so no pollenizer is needed. Choose a dormant bare-root bush.
Prepare the site. No special preparation is needed for the planting site. Blackberries are shallow rooted, so dig a hole or trench just deep enough for the roots. For multiple plants, space them 4 feet apart in rows 10 feet wide.
Prune the newly planted blackberries back to 6 inches.
Apply a general-purpose fertilizer as soon as the buds begin to swell. Apply fertilizer yearly in early spring just after buds swell.
Add a 1- to 2-inch layer of mulch around and in between the plants. This will help the plants retain moisture and limit weed growth. You will need to reapply mulch yearly after applying fertilizer.
Wait for the plants to bear fruit. It will take 2 years for your new bushes to begin to produce fruit. Blackberries have two types of canes: first-year nonfruiting canes called Primocanes and second-year fruit-bearing canes called Floricanes. Floricanes die after fruit production, so they should be cut to the ground after all the berries have been picked.
Train trailing blackberry brambles on any type of trellis or fence. Select the sturdiest canes to trellis and cut the rest to the ground. Remember, you must leave both first-year and second-year canes on the plant at all times for berry production. Erect and semi-erect blackberries do not need trellising.
Water the plants. For optimal berry production blackberry plants require 1 to 2 inches of water per week during the growing season.
Prevent disease and pests in your plants. Since blackberries can succumb to a number of diseases and pests, prevention is the key to keeping your plants healthy. Buy only certified disease-free plants. Fertilize, mulch and remove dead or broken canes. Check your plants weekly for signs of disease and pests. Some common signs are yellowing leaves, black spots, holes in leaves, blossom drop or non-fruiting and canes with dead tips. Contact your local extension office for advice if you see any of the above.