Q: When do you prune blackberries?
A: Remove dead canes immediately after fruiting in the spring. Be careful not to cut out the new canes in the process as they represent next year's crop. The new canes should be tip pruned from June to September to form a bushy hedge to facilitate harvest.
Q: What do you use to fertilize blackberries?
A: Use 21-0-0 or 15-5-10 depending on your soil pH. If your soil pH is above 7 use only 21-0-0 and use 15-5-10 for the first application if your pH is below 7. Use about 4 - 5 pounds per 100 feet of row. Make the first application in early spring, usually right before budbreak. A second application can be made in June if the growth is poor. Use 21-0-0 for the second application regardless of soil pH.
Q. When is the best time to plant blackberries?
A. The best time to plant berries is in January and/or February. Blackberries are best started from root cuttings, but you will need plants to establish raspberries. The best blackberries for your area are Brazos, Rosborough, and Shawnee. There are two thornless blackberry selections you may want to try, Navajo and Arapho. The only raspberry which will survive in your area is Dorman Red. Although it does not have the quality that the northern raspberries have, it is a raspberry which will grow in the south.
The only significant problem you may encounter is iron chlorosis caused by high pH soils. You will probably need to apply iron chelates if your soil pH is above 7.5.