The blackberry (Rubus spp.) is a member of the rose family and, like the strawberry, it is not a true berry, but what is known as an aggregate fruit. Borne on a biennial fruit-bearing bush, the blackberry is native to Asia, Europe and the North and South American continents. There are three types of blackberry bushes: erect, semi-erect and trailing and there are thorny and thornless varieties within each type.
Provide the blackberry plant 1 inch of water a week from the middle of June until harvest. During particularly warm or windy weather, they may require an extra 1 inch of water.
Fertilize the blackberry plant in early spring with 5 lbs. of 10-20-10 fertilizer for every 100-foot row. Spread the fertilizer over the soil and water it in.
Remove weeds as they appear throughout the season. Use the hoe to cultivate no deeper than 1 inch.
Remove the top 2 inches from first-year canes, called primocanes, when they reach 3 feet tall, in the summer. This will encourage the plant to produce the branches that will provide next year's fruit. In the winter, remove all but three or four of the strongest primocanes but cutting them to the ground. Prune the lateral branches of the remaining primocanes to 12 inches long.
Cut off 2-year-old canes, or floricanes, after the harvest. These branches will die after fruiting so it's best to remove them.